Ultrasonic HDPE Fusion Weld Testing

HDPE fusion weld testing

The need for excellent performance and durability of components drives the selection of materials in industries. Recent years have seen a rise in demand for HDPE (High-Density Polyethylene) because of the many advantages it provides compared to the other conventional metals like carbon steel for industrial piping systems. Its excellent corrosion and chemical resistance, strength, and flexibility make it ideal for water supply, petroleum transport, and chemical supply plants. 

However, given the fundamentally different chemistry of the HDPE, the fabrication process involved is also unique compared to its metallic counterparts. But the fundamental principle of its use for industrial operation remains the same; that is, the weld should be free of flaws and discontinuities. To ensure that the mechanical properties of the HDPE pipes or tubes are not compromised during the welding, nondestructive testing (NDT) plays an effective role. Here, we will discuss the importance of NDT, such as ultrasonic testing (UT) in HDPE fusion weld inspections. 

HDPE Fusion Welds and UT Inspection

The most common welding process for HDPE fusion is the butt welding process. The process involves the use of a hot plate to heat the flat ends of the to-be-fused HDPE pipe, tubes, or fittings, which are then pressed together mechanically to form a bond. During the process, the following conditions should be met:

  • The temperature of the heating plate should usually be between 150℃ to 300℃.
  • The two heated surfaces should be joined together under controlled pressure. 
  • The weld component should not be exposed to extreme environments or external inclusions as a weld preparation.
  • The alignment of the HDPE pipes should be checked before fusing them under pressure. The maximum allowable misalignment should be less than 10% of the wall thickness of the pipe. 

Violation of any of these fusion conditions can lead to flaws in the weld, such as lack of bond, porosity, cracking, and inclusions. To ensure these flaws do not interrupt the industrial operation, phased array ultrasonic testing (PAUT) is ideally used for the HDPE butt fusion weld inspections. 

Learn more about Inspecting HDPE butt fusion welds.

As HDPE has a high attenuation,the conventional high-frequency UT inspection process is not optimal. As such, a recommended solution has been established as a combination of PAUT with TOFD (Time of Flight Diffraction). TOFD with PAUT facilitates:

  • Higher sensitivity to detect even the minute flaws. 
  • Focused beam for scanning in weld areas with irregular surfaces and thicknesses.
  • Larger coverage of the weld area and the heat-affected zone. 
  • High-resolution scanning and imaging for flaw sizing.  
  • Vertical flaw detection.

By precisely identifying the flaws that are potential risks to the industrial system, these NDT solutions foster time and cost-saving in HDPE inspection and ensure productivity. 

Learn more about TOFD inspection of HDPE piping

Learn more on the webinar: Ultrasonic Inspection Solution for HDPE Butt Fusion Joints.

HDPE Welding in Industries

In the petroleum industry, the demand for HDPE pipe is seeing a boost, given the excellent advantages of corrosion and erosion resistance desired for the transport of crude oil. Especially in applications with low pressure and low temperature, i.e., less than 60℃, HDPE has replaced carbon steel with its advantage of strength and easy weldability. HDPE is also popular because of its chemical stability which facilitates its use for petrochemical use without the incidence of any chemical reaction. As such, the inspection of HDPE welds holds greater importance given their role in ensuring the strength and safety of petroleum applications. 

HDPE fusion weld testing with PAUT enables accuracy in flaw detection. With proper corrective actions guided by the flaw characterization, possible leaks can be easily prevented, which can be disastrous in the oil and gas industry. 

Read more about HDPE welding in the petroleum industry.

Ultrasonic Solutions to Overcome HDPE Inspection Challenges

In HDPE, difficult-to-detect flaws are induced with incorrect heating and surface preparation techniques. Adding to the ultrasonic inspection challenge is the high attenuation factor of HDPE and the vertical fusion welding method. 

With a low-frequency PAUT probe, flaws can be detected with high precision and accuracy. TOFD enabled PAUT provides greater sensitivity of identifying flaws in a wide range of orientations. With volumetric HDPE fusion weld testing enabled with phased array ultrasonic NDT, a variety of industries can ensure productivity and efficiency in their respective operations. 

Zetec provides specialized ultrasonic NDT solutions that provide the advantage of excellent flaw detection in HDPE fusion weld testing. For quality equipment and tailored inspection plans, contact us today to learn more. 

Friction Stir Welding Inspection: What to Look Out For

friction stir welding

As a relatively newer welding process, friction stir welding has seen an increase in use in offshore, aerospace, automotive, shipbuilding, and other similar applications due to its many advantages. It is a solid-state welding technology that fuses two similar or dissimilar metals using a non-consumable tool. The weld formed with friction stir welding is typically stronger than the typical fusion welding process with a smaller heat-affected zone. 

However, the weld achieved can not always be free of flaws and defects, which may potentially make the welded component inoperable. Friction stir welding inspection performed correctly can identify flaws in all orientations, ensuring adequate coverage for high-quality results. 

Friction Stir Welding Inspection

The welding mechanism of friction stir welding differs from the conventional welding process in that it does not arc or flame to join two pieces of metal. Instead, the two metal pieces are clamped together while the rotating device is driven along the weld interface. The friction generated between the rotating device and material surface due to high speed creates heat, softening the material. 

The softened material from the metal pieces fuses under pressure to create a weld. The weld thus formed has a smaller heat-affected zone with reduced stress and distortion. The welding process embraces high-level automation, and its high speed facilitates the joining of thick metal pieces in a relatively short amount of time.

During the welding process, inaccurate design and weld parameter control can generate defects, including kissing bonds (incomplete bond continuity between materials), cracks, wormholes, and lack of penetration. These defects can be visible on the surface or lie in different orientations within the subsurface, making it difficult to visualize.

Nondestructive testing (NDT) of friction stir welding can help maintain weld quantity with reliable inspection, wider coverage, and improved odds at defect identification. Phased array ultrasonic testing (PAUT) and eddy current array (ECA) both serve as potentially effective NDT solutions.

Solutions for Friction Stir Welding NDT

Traditionally, there has been a need for multiple probes, each individually aligned and calibrated, to address the inspection needs of friction stir weld. The inspection process is generally time-consuming with a standard probe, with less coverage and less reliability in identifying defects in all orientations. 

The right phased array ultrasonic testing (PAUT) portable and scalable instruments and approach can make this challenging inspection process faster and easier with their quick setup and calibration ability. Since PAUT uses multiple small transducers, the inspection coverage can be increased. It is recommended that 3 beam angles be used for inspection of parallel flaws in friction stir welding along the weld seam. This is supported by the PAUT, where the individual elements can be pulsed at different times for ultrasonic beam generation. The beam angle can be changed for each pulse, facilitating sectorial scanning for a wide range of angles. For friction stir welding inspection, PAUT enables merging of all scanning sequences along the beam angles +45°SW, 0°LW, and -45°SW, for complete coverage in a single scan. 

Zetec’s PAUT instruments such as TOPAZ64 (change hyperlink) and Emeraldcan provide complete features needed for performing friction stir weld inspection. NDT technicians can leverage the following advantages:

  • Parallel firing capability
  • Improved sensitivity and sizing capability
  • 0°LW and 45°SW beam angle generation for flaws that are transverse or parallel to the weld centerline
  • Simplified calibration and optimization ability
  • 1D linear array and 2D matrix array probing
  • Data throughput of up to 30MB/s

Similarly, ECA instruments such as MIZ-21C from Zetec also support inspection through conductive materials like aluminum to identify surface or near-surface flaws. NDT inspectors can utilize features including:

  • C-scanning
  • Depth sizing
  • Multi-layer inspection

With flexible ECA probes, inspectors can perform inspections in harder-to-reach areas and identify minor flaws that may affect the component’s performance. 

The simplified scanning process of the weld with PAUT and ECA equipment allows industries to reduce the inspection time while improving reliability significantly.

Improving Efficiency of Friction Stir Welding Inspection with NDT

Compared to conventional eddy current and ultrasonic testing, ECA and PAUT probes can be successful in identifying hidden cracks and pores in the metal. Advanced NDT probes can be optimized to support flaw detection across different orientations. Through reliable capture of weld defects and discontinuities, industries like shipbuilding or aerospace can ensure the quality of their components. 

Multi-elemental probes and their excellent repeatability feature can be relied upon for improved coverage, and thus, reduced inspection time. With enhanced friction stir welding inspection systems, industries can minimize the many challenges they face in maintaining the product and manufacturing standard.

Zetec provides a range of exceptional phased array ultrasound testing instruments and probes for friction stir welding inspection to facilitate your need for faster NDT and improved operational efficiency. To find the best NDT solution for your testing needs, contact us today. 

How Ultrasonic Inspection of Forgings Ensures Quality Products

Forging is a necessary metalworking process where metal parts are molded or pressed to achieve the desired design requirement. Modern industrial components such as rotors, shafts, turbine blades, and landing gears are mostly forged and provide similar or enhanced mechanical properties as the machined or cast components. 

However, due to compression and deformation processes that the metal has to go through, the internal texture of the metal changes gives rise to defects. For this very reason, nondestructive testing (NDT) is necessary. By inspecting the type and extent of flaws and defects, the quality of the forged product can be ensured. 

Understanding Forging Defects and Ultrasonic NDT

Forged structures are preferred by industries in applications with high strength requirements. Different forging mechanisms are responsible for developing various types and degrees of forging defects.  

Based on temperature ranges, these forging mechanisms can be classified as hot forging (metal is heated to their melting point) and cold forging (little heat is used). These forging processes bring about the change in the microstructure of metal due to thermal variation. Hence, the following types of flaws can be observed:

For metals such as steel, aluminum, brass, copper, titanium, etc., which can be shaped with a forging mechanism for use in various applications, NDT methods such as ultrasonic testing (UT) provide an ideal solution for identifying the flaws mentioned above. 

Other NDT methods, including visual inspection, magnetic particle testing, radiographic testing, and liquid penetration testing, have been utilized to inspect forged parts. However, they all have their limitations in ensuring complete coverage of all apparent and underlying defects. 

UT is sensitive to both surface and subsurface discontinuities and can provide a highly accurate picture of the flaw attributes. However, this is only true for conventional UT when the defect is not aligned parallel to the ultrasonic beam. For more advanced and volumetric inspection, phased array ultrasonic inspection of forgings can prove beneficial.

Phased Array Ultrasonic Testing of Forgings

Phased array ultrasonic testing (PAUT) operates using a series of individually inducible transducers in a single probe. The beams through each transducer can be separately controlled, focused, and swept without moving the probe. This allows for scanning across diverse angles, enabling the detection of underlying, hard-to-detect flaws in any orientation. Furthermore, a single PAUT probe can facilitate:

  • Volumetric coverage with the help of multiple transducers
  • Inspection of complex geometrical structure made easier with a customizable beam angle 
  • Sensitivity to minor defects with a controlled focus
  • Increased inspection speed due to large area scanning ability
  • Reduced inspection cost through time saving efficiencies

The PAUT instrument solutions such as TOPAZ from Zetec provide an integrated 2D matrix array feature without needing any external software, making the inspection process more efficient. Conventional UT probes can find it challenging to identify flaws in different orientations during forging inspection due to their fixed beam positioning feature. 2D matrix array enables enhanced beam steering for detecting out-of-spec defects with a complete 3D volumetric inspection.

Similarly, with products such as the paintbrush corrosion scanner, conformity to different geometric systems and complete coverage can be assured. Not only that, with high-quality imaging and real-time inspection analysis, technicians can easily locate flaws and analyze inspection data.

NDT Ensures Quality of Critical Forged Components

Any defect development can be damaging for components that are specifically forged to improve product strength. With different materials being forged in varying geometries for different applications, it is necessary that an NDT solutioncan fulfill all inspection requirements. 

Zetec’s TOPAZ and paintbrush scanners are effective for ultrasonic inspection of forgings. Through smooth scanning and enhanced data analysis, technicians can easily find hidden flaws, which ensures product quality.

Zetec, a leading provider of NDT instrumentation, can help with maintaining product quality for forge components. Contact us today to discuss the NDT solutions for your application and receive a custom plan for ultrasonic inspection of forgings.

The Many Roles of NDT in Aerospace

For both civilian and military purposes, aerospace manufacturing is subjected to tough design specifications and quality standards. Additionally, they also need to strictly verify the quality of the aircraft engine, body, and related components before the operation and frequently during service. This is to address the high stake of human lives associated with the industry. 

NDT has been a primary quality assessment and component inspection practice in aerospace industries for decades. It ensures the provision for inspecting a wide range of components quickly and efficiently in a volumetric manner. For this, the aerospace industry has been relying on NDT solutions from providers such as Zetec with their advanced eddy current and ultrasonic testing equipment that has helped industries ensure flight safety for decades. 

NDT Inspection of Vital Aircraft Composites

Composites are extensively used in the aerospace industry for components such as the body frame, engine blades, wings, and fuselage. It is a desirable choice due to its lightweight quality while providing similar structural strength as other metals. The defects induced in these composites during manufacture or in-service can be successfully scanned using phased array ultrasonic testing (PAUT) instruments with a proper inspection technique. The modern PAUT scanners and probes provide flexibility, accuracy, and reliability when detecting damages in aerospace composites which may include delamination, cracking, inclusions, and porosity. Qualified technicians along with powerful inspection solutions can help maintain standards for NDT in aerospace industry.

Learn more about Strategies for NDT of aerospace composites.

Understanding carbon fiber is imperative when we discuss aerospace composites. NDT inspection of carbon fiber reinforced plastic (CFRP) composite for the aerospace industry benefits from the time-reversal PAUT technique, providing improved signal quality, coverage, and probability of defect detection. 

Read more to Understand the NDT of carbon fiber

Portable PAUT equipment such as a paintbrush scanner can detect the underlying flaws in composites while exhibiting excellent flexibility to inspect along curved or flat surfaces.  With excellent data processing ability, fast scanning, improved user interface, and configurability, different inspection needs for composites can be met during aircraft inspection.

Learn more about the best equipment for nondestructive testing of composite materials.

The use of PAUT probes with the time-reversal capability can overcome the challenges of complex geometry and variable thickness inspection problems faced by a standard PAUT in aerospace testing of composites. Through enhanced probe alignment ability and auto inspection system facilitating efficient surface profiling, data capture, and analysis, time-reversal PAUT can produce faster and precise results. 

Read more about Automated composite inspection technique with time-reversal phased array.

Examining Aerospace Components with NDT

Every takeoff and landing takes a toll on the aircraft wheel due to extreme heat and braking force. As an important part of the aircraft, wheels should be subjected to NDT inspection for potential defects like cracks. For improved accuracy, faster inspection, and cost efficiency, many technicians trust eddy current testing (ECT).    

Read more about the efficient aircraft wheel NDT tools

The defects induced in propellers due to heat or stress can be difficult to visualize manually. As propellers are mostly made of composites, most defects may be underlying. To identify the flaws, quality inspectors can use NDT techniques such as ECT and UT. ECT is favorable for identifying surface defects, especially in conductive alloys. UT is suitable for locating subsurface defects and is a perfect solution for composite inspection.

 Learn more about finding the right NDT equipment for propeller inspection.

Maintaining Standards with NDT in Aerospace Industry

The integrity of military aircraft is important in ensuring mission readiness, which is why they have to be inspected to meet certain design and manufacturing standards. Qualified technicians with different levels of expertise periodically inspect to ensure component quality using NDT. In addition, ECT and UT can serve to detect dangerous flaws and discontinuities with the powerful and precise scanning ability that can accommodate complex geometries, varying materials, and remote, difficult-to-reach spaces. 

Learn more about NDT in the air force.  

The value of commercial aircraft is associated with its top-tier performance that can provide travel efficiency while ensuring the safety of the crew and passengers. This can be achieved by identifying the underlying defects that can affect the integrity of the aircraft components. UT and ECT can produce high-quality inspection results in less time versus many legacy inspection approaches, facilitating quality assurance with less downtime. 

Learn more about NDT for commercial aircraft.

NDT for commercial and military aerospace use requires adherence to standards laid out by government and international bodies. For example, in the US, the Federal Aviation Administration recommends the provision of annual inspection certification. Compliance with the federal and international regulations during manufacture and maintenance helps keep the crew and passengers safe and ensures the durability of the aircraft.

Learn more about NDT standards for aviation.

NDT Solutions for Enhancing Safety in Aerospace Industry

Different inspection technologies have been used for aircraft inspection, but many have not been as efficient as eddy current and ultrasonic testing techniques. The advanced NDT equipment available in the market supports high volume inspection with their higher sensitivity to flaws during precision scanning. Complex inspection can be made easier and aviation standards can be maintained with NDT in the aerospace industry.

Learn more about Aerospace NDT inspection solutions.

Zetec has been providing advanced PAUT and ECT technologies for flaw detection in the aerospace industry for several decades. To learn more about our solution for NDT in aerospace, contact us today.

Inspecting Power Distribution Busbars

Busbars are an integral part of electrical systems in small or large-scale industrial applications. Since busbars are responsible for power distribution, their quality is important in ensuring proper inflow and outflow of electricity. Quality in a busbar implies that it should be free of flaws so it can operate at its full potential. 

In all the industrial applications that the power distribution busbars are used, their inspection can be carried out with the help of nondestructive testing (NDT) technology. Especially eddy current testing (ECT) has been proven efficient in testing busbars of different materials, shapes, and sizes. Here we discuss it further. 

What Are Power Distribution Busbars?  

Busbars are used in power distribution systems to ensure proper flow of current in high-voltage applications. Often made up of metals, busbars can be found in various shapes (i.e., solid bars, flat metallic strips, or rods) and size that the technician can select depending on the maximum electric current requirement for the application. 

Power distribution busbars are usually found enclosed within switchgear, panel boards, or busway enclosures. It acts as a junction where all the incoming electric current is collected before it is distributed. Busbars allow different circuits to branch off anywhere along the busway rather than the traditional way of branching from the single main switch location. 

Each power distribution busbar has its individual isolator and circuit breaker, which trips when a wiring fault is detected. This can not only prevent possible damage to the main switch, but also makes it easy to disconnect and replace the faulty busbar. 

This functionality has made the power distribution busbar system a popular alternative to the electrical wiring system in most small and large-scale industrial applications. Some other advantages include:

  • Rapid installation process
  • Easy addition or removal of busbars
  • Easy maintenance with no downtime
  • Cost-efficiency

These benefits have been leveraged by electrical components in many industries for applications such as:

Defect Development in Busbars

With the expanding use of power distribution busbars, it is important to understand how potential flaws may develop in busbars and how they can be identified. The initial possibility of defect arises during the manufacturing process of busbars, where processes like stamping or machining can cause the metal to crack. Similarly, busbars can experience high stress and temperature deviations in high voltage operations, leading to fatigue cracking. 

These flaws in busbars can be identified with the help of NDT. For small-scale industrial equipment and large-scale power generation applications, NDT can ensure that busbars are defect-free so that problems like arching and shorts in the power transmission system can be avoided. 

Nondestructive Testing Power Distribution Busbars

NDT inspection of the power distribution busbar requires assessment of complex geometries, contoured surfaces, and bends as well as inspection through non-conductive coatings.  Eddy Current Array (ECA) has proven to be an effective NDT method capable of providing reliable results for such requirements. 

The multi-coil arrangement of the ECA probes provides versatility in inspection, by which it can:

  • Improve the inspection speed and provide large surface area coverage.
  • Improve scanning sensitivity and accuracy for accurate defect sizing. 
  • Conform to the changing contours to facilitate complete coverage (along bends in busbars)

The flaws such as surface and near-surface cracks can be easily identified with ECA solutions which can inspect the component in a single pass, minimizing downtime and improving cost-efficiency in all power distribution applications. 

Zetec’s NDT solutions, such as Surf-X Eddy Current Array probe and MIZ-21C, provide inspectors the ability to flexibly scan and display the data to improve the probability of defect detection. For the effective operation of your power distribution application, Zetec’s NDT solutions can provide accuracy and precision in inspection to ensure the quality of the busbars.

Zetec’s advanced NDT solutions can assist you in the efficient inspection of power distribution busbar, whether for small-scale industrial equipment or large-scale power generation application. Contact Zetec today to create your custom power busbar inspection solution.

Testing Wind Turbine Components: How NDT Improves Wind Energy Reliability

The increasing need for clean energy has increased interest from investors across the globe in renewable energy projects like wind farms. In 2020, wind energy will contribute 8% of the U.S.’s total electricity generation. However, to improve the consumer reliability of wind energy and increase the number of projects, it is also necessary to ensure that the existing wind turbines and their components function correctly to provide a longer service life. 

Wind turbines used for utility-scale electricity generation are complicated structures consisting of many complex components, including turbine blades, busbars, rotors, shafts, gears, and other mechanical components. Enhanced inspection leveraging the advantages of nondestructive testing (NDT) can help guarantee the quality of these wind turbine components. By reducing risk and enhancing the operation of wind turbines, NDT can help wind be a dependable source for commercial energy use.

Wind Turbine Components and Its Assessment

Components of a wind turbine require a timely inspection to ensure structural integrity. 

However, the flaws can be introduced in the components as early as during the manufacturing phase. The commonly observed defects include inclusion, delamination, micropitting, voids, cracks, corrosion, and lack of fusion in joints. During installation and operation, these flaws may further exacerbate under different stress and load conditions. A common example includes exposure to heavy wind and storm conditions which can severely damage the turbine blades. The time-varying nature of wind conditions also means the wind turbine components may be prone to fatigue, further increasing the chances of failure.

Technicians must be mindful of assessment procedures for composites, welds, and material inspection for possible surface and subsurface defects in wind turbine components. NDT methods such as ultrasonic testing (UT) and eddy current testing (ECT) have effectively identified these flaws and ensured the quality of wind turbine components. 

Learn all you need to know about Wind turbine non-destructive testing

NDT Minimizes Chances of Wind Turbine Failure 

UT Inspection of Wind Turbine Components

Turbine blades usually have materials such as resins, fiberglass, and metals such as iron, steel, and aluminum. Delamination and cracks can be difficult to detect if they are hidden within the composite layers. Air bubbles and inclusions can be trapped within the fiber layers during the resin flow in the production process. The aerodynamic load can lead to the development of fatigue cracks, and corrosion can result from environmental conditions. In addition, complex blade geometry can present a challenge during scanning for conventional UT probes. 

Additionally, weld defects in wind towers should be subjected to NDT inspection along with micropittings in gear teeth and bearings developed due to varying load, changing speed, and vibration. 

Detection of these flaws during wind turbine inspection can be made easier with advanced UT techniques such as phased array ultrasonic testing (PAUT). Unlike conventional UT, PAUT provides customized beam focusing ability for technicians to send and receive signals along a range of angles in multiple directions. The improved probe sensitivity facilitates detection of all minor flaws that may be difficult to detect visually. 

The high-frequency beam can easily analyze thicker welds and materials of attenuative nature. A comprehensive single-probe analysis ability can provide faster inspection, and high flexibility enables complex geometrical inspection. 

ECT Inspection 

ECT is most prominently used when inspecting key structural components such as busbars and gears for detecting surface and near-surface defects. The material composition, stress, temperature fluctuation, and mechanical use of these components dictate the extent of defect development. The advanced ECT technique such as Eddy Current Array (ECA) facilitates effective weld and material inspection to identify defects and discontinuities such as cracks, corrosion, and pits. 

Unlike conventional ECT, multi-element ECA probes provide greater sensitivity and wider coverage in a single pass. With modern flexible and portable surface array probes, inspection on weld joints, contoured surfaces, and bent areas is made easy, such as curved wind turbine towers and bent areas in busbars. In addition, the provision for +point coils in ECA probes such as Zetec’s Surf-X Array facilitates flaw detection in hard to inspect areas. 

The selection of the right instrument allows NDT inspectors to examine all critical wind turbine components with a greater probability of defect detection. Zetec’s compact and portable solutions can help with quick and accurate inspection to minimize the chances of wind turbine failure.

Quality Inspection Fosters Wind Energy Reliability 

Regular inspection is a necessary measure to establish the quality of wind turbine components. ECA and PAUT techniques are effective in inspecting these components pre-service as well as during operation. Zetec’s ultrasonic and eddy current solutions, including MIZ-21C, Surf-X Flexible Array Probes, and TOPAZ provide flexibility in inspecting many types of materials and geometries in many locations. With enhanced sensitivity, analysts can easily deduce otherwise difficult to assess defects. 

The complex structure of wind turbine components and varying loads means a greater probability of wear and tear and chances of structural failure. NDT of wind turbine components is thus extremely important to reduce the potential failure and downtime. With cost-effective and faster inspection options, it is possible to improve the reliability of wind energy as a prominent renewable energy option. 

Zetec is a leading provider of advanced ECT and UT instruments that can help you inspect wind turbine components, including turbine blades, busbars, gears, and many more. To develop a custom NDT plan for wind turbine inspection needs, contact Zetec today.

The Advantages of Eddy Current Tests on Large Area Surfaces

Eddy current testing (ECT) has become one of the most popular nondestructive testing (NDT) techniques for inspecting conductive materials for surface and subsurface flaws. Eddy current testing of large areas or complex surfaces can be taken to the next level with an eddy current array (ECA)—a system capable of producing detailed three-dimensional renderings of flaws, including extremely small indications that can elude other NDT techniques.

ECA has the benefit of quickly performing an eddy current test on a large area without the need for coupling fluid, making it an ideal technology for identifying cracks, signs of fatigue, corrosion, and other surface and near-surface flaws. Here, we can discuss some of the major types of flaws that affect metal surfaces and how ECA can improve the ability to detect them.

How ECT Works to Uncover Flaws

Basics of Eddy Current Testing (ECT)

ECT uses the principle of electromagnetic induction to test for flaws in conductive materials. In its most basic form, a single-coil ECT probe is energized with an alternating electrical current, which generates an oscillating magnetic field around itself. When the probe approaches a test piece made of a conductive material, it induces an eddy current in the material.

Any flaws or discontinuities in the test piece cause changes in the eddy current’s amplitude, measured by the probe and used to generate a visual representation of the test surface.

ECT has several advantages over other NDT techniques:

  • Can be used with both ferrous and non-ferrous materials, as long as they are electrically conductive
  • Can penetrate non-conductive coatings
  • No coupling fluid or surface preparation required
  • Produces a computerized record of the inspection

Common applications of ECT include surface inspection, corrosion detection, bolt hole inspection, and weld inspection.

Eddy Current Array: Eddy Current Testing for Large Areas

Some of the drawbacks of single-coil ECT are that it can only be used to test a small area at a time and can only reliably detect flaws that are oriented perpendicular to the eddy current. This is fine when the direction of potential linear flaws like cracks is known, but getting a thorough picture of the test piece, including flaws in multiple orientations, requires multiple passes, increasing inspection time. 

The eddy current array (ECA) overcomes this limitation by combining several single-coil ECT probes on a grid that produce signals in both the axial (direction of scan) and transverse (perpendicular to scan) directions. The coils fire in a coordinated way to create a three-dimensional image of the surface and subsurface in a single pass, simplifying eddy current testing of large areas and speeding up inspection times by as much as 95 percent compared to traditional probing techniques.

Compared to single-coil ECT, some of the advantages of ECA include:

  • Faster inspection time
  • Easier technique
  • More accurate and repeatable results
  • More information captured in a single pass
  • Can find linear flaws 
  • Provides high confidence in full surface coverage
  • Powerful reporting and data recording capabilities

Types of flaws

Several types of flaws can occur on metal surfaces. ECA inspection is effective at detecting most types of linear and volumetric discontinuities, such as:

  • Cracks
  • Incomplete fusion/separation
  • Pitting corrosion
  • Porosity/voids

Linear flaws: Cracks, Laps, Separation

ECA inspection is ideal for detecting cracks and other linear discontinuities caused by fatigue or manufacturing flaws. It can identify all kinds of surface and internal cracks, including:

  • Stress/fatigue fractures
  • Tip cracks
  • Weld root cracks
  • Forging bursts
  • Incomplete fusion/forging laps

The best eddy current instruments can detect cracks for complex inspections like tubing using multiple frequencies and dual options and can detect cracks as small as 0.1 mm or less in depth.

The 3D renderings produced by ECA inspection make it easy to see where cracks are developing and their orientations. Furthermore, ECA can show variations in crack size and depth that may not be visible with other NDT techniques like liquid penetrant testing (PT) or magnetic particle testing (MT).

Watch our webinar to learn more about the advantages of eddy current array (ECA) testing compared to liquid penetrant testing (PT) and magnetic particle testing (MT).

Volumetric flaws: Corrosion, Pitting, Voids

ECA’s three-dimensional imaging capability also makes it effective for identifying volumetric flaws like voids, pitting corrosion, or generalized corrosion and distinguishing these flaws from linear ones.

ECA effectively penetrates tough welding sections to detect indications of corrosion. The signal-to-noise ratio can help pinpoint the slightest deviations or material losses resulting from corrosion, in addition to abnormal changes in thickness. 

Corrosion can often produce multiple flaw types simultaneously, such as pitting and corrosion cracking. The ability to see indications in both the axial and transverse directions makes it easier to distinguish between these flaw types, providing a clearer picture of the problem and its causes. 

While single-coil ECT, PT, and even visual inspection might all be able to detect corrosion, the specific types of flaws might not be obvious. For example, ECA’s axial and transverse channels clearly distinguish between volumetric flaws visible on both channels and linear flaws, which only show up on the channel perpendicular to the flaw.

ECA Technology for Eddy Current Testing on Large Areas

From detecting extremely small indications to performing eddy current tests on large area surfaces in a single pass, Zetec can help.

Zetec has been a global NDT leader for over 50 years, and we’re constantly advancing the science and technology of eddy current testing and other NDT technologies. Zetec’s proven expertise and product portfolio set the standard for the inspection needs of the aerospace, transportation, power generation, manufacturing, and oil and gas industries.

When it comes to performance, accuracy, dependability, and affordability, eddy current array solutions may be a key asset. To learn more about our ECA inspection solutions for your company, contact Zetec today.

Using Ultrasound Plane Wave Imaging in NDT

Using Ultrasound Plane Wave Imaging in NDT with Zetec's Emerald.

Across many industries, technicians and engineers have strived for high accuracy and efficiency in flaw detection. In the medical field, this has been achieved with the help of Plane Wave Imaging (PWI) technology. Plane wave imaging holds the promise of producing high-resolution imaging through scan and precise flaw detection. Now, this technology is gaining popularity in other industries as a data acquisition method for ultrasonic non-destructive testing (NDT)

Rapid data acquisition and analysis through ultrasound plane wave imaging —often in conjunction with full matrix capture (FMC) and the total focusing method (TFM)—provide many advantageous prospects for industries.

Ultrasound Plane Wave Imaging

The phased array ultrasonic testing (PAUT) NDT technique has been mostly preferred by industries for its ability to generate focused imaging, accurate results, and faster inspection. Often, for more advanced inspections this can be supported by FMC data acquisition and TFM algorithms to digitize and analyze the data for later or even real-time processing. The A-scan signal data thus stored in the form of a matrix grid is instrumental in developing high-resolution imaging for flaw detection. 

However, TFM requires more computing power for the analysis of large numbers of data in the matrix grid. In addition, FMC data can generate extremely large size data files and requires extensive processing power for real-time data reconstruction. As a result, many inspections rely on heavy external computer processing for TFM image reconstruction.

Plane wave imaging simultaneously excites all available elements in an array for the transmission of ultrasonic signals at different angles. Simultaneous excitation means a single transmission circuit can be used for the process. Plane wave imaging also reduces the number of excitation required to capture the data. Few excitation and wide area coverage allow for faster data collection, processing, and analysis. The data collected is stored in form of a matrix. At each angle, the plane wave data acquisition recreates the dynamically focused image at different depths. By adding these images, the final image can be achieved. This resulting image can be used to identify the type of flaws in the component. 

Benefits of Utilizing Ultrasound Plane Wave Imaging

Compared to TFM/FMC, ultrasound plane wave imaging offers many advantages in data acquisition and processing. For industrial NDT, plane wave imaging can facilitate:

  • Less computation time due to increased scan area and less excitation requirement
  • High-quality data and high-resolution imaging
  • Single transmission circuits that lead to ease of inspection with less complicated hardware 

In addition to the advantages plane wave imaging offer, industries should also be wary of some issues:

  • With a reduced number of excitations, the amount of data or signals collected can be less.
  • High computation power may be required for real-time data processing. 

Ultrasound Plane Wave Imaging Solutions for Improved flaw Detection

Industries are now leveraging the advantages of ultrasound plane wave imaging for NDT data acquisition and analysis. Zetec has introduced the EMERALD system with powerful TFM image processing capability. EMERALD offers:

  • Plane-wave imaging as a powerful data acquiring technique with up to 128 elements 
  • Advanced plane wave image reconstruction ability with A-scan signal processing along every angle and acoustic path

Using ultrasound plane wave imaging for NDT allows industries to focus on efficiency and productivity through its advanced image processing and flaw detection ability. Look for systems that offer fast and efficient onboard processing capabilities, along with superior signal quality designed to achieve high amplification without distortion. This can make a big difference in inspection productivity. 
With the right equipment, technicians and engineers can quickly analyze images—even from complex configurations to help foster quality and safety in industrial operations.

Zetec is a leader in nondestructive testing solutions with options for advanced ultrasound plane wave imaging algorithms for precise image capture and flaw detection. To find the NDT equipment which best suits your testing needs, contact us today!

Advanced NDT Software for Metals, Materials, and Composites

Nondestructive testing (NDT) methods, such as eddy current testing (ECT) and ultrasonic testing (UT), provide the ability to inspect for surface, subsurface, and internal discontinuities or flaws, ensuring the safety and reliable performance of welds, components, and structures. However, NDT methods are only effective if properly used. If NDT equipment isn’t set up correctly, for example, defect indications might not be visible. Likewise, defects can be missed or misclassified if technicians are not adequately trained to interpret the results.

Fortunately, these concerns can be largely addressed by facilitating as much of the inspection process as possible using NDT software tools. In this post, we will discuss how advanced NDT software can improve the value and reliability of both eddy current (ECT) and ultrasonic testing (UT).

How NDT Software Can Alleviate Testing Concerns

Whether using ECT or UT technology, an effective NDT process must be able to:

  • Consistently identify critical indications
  • Produce results quickly
  • Make it easy to see trends over time

Traditionally, analysts had to interpret NDT results off-site or in a less visually intuitive approach, which can present a few problems. This type of analysis requires highly experienced, trained technicians to identify defects accurately. The process is time-consuming, and the subjectivity involved opens the inspection process to variation.

Now, many industries may be replacing this type of analysis with advanced NDT software that can help control the scan, collect and analyze data in real-time, and generate images, greatly improving speed and consistency over legacy analysis. For example, 2D or 3D images generated by software such as UltraVision allow technicians to quickly and easily identify defects. In addition, the right NDT software produces accurate, consistent, fast, and easy results for the technician to interpret.

Below is a summary of some features NDT software can provide and how they can improve inspection processes:

Feature Advantage
Coverage MappingProvides understanding of detection capability and inspection coverage
Inspection SimulationMakes testing more predictable
Analysis ToolsReduces inspection time, makes results more repeatable/reproducible
Real-Time AnalysisProvides immediate awareness of indications
Flaw Detection and ClassificationImproves detection rate and consistency of defect classification
Noise MonitoringReduces false positives and streamlines inspection
User Configuration LockingSafeguards against errors and guarantees control over results
Historical Data ComparisonProvides early warning of problems and better understanding of process capability
For more information about software solutions for Ultrasonic Testing (UT), see our UltraVision software packages.

Industry Applications for NDT Software

The benefits of NDT software can be found anywhere UT or ECT could be employed for inspection. Below are some examples of how NDT software can improve inspection processes in the oil and gas and aerospace industries:

Oil and Gas Pipelines

UT is commonly used for weld inspection and corrosion mapping in pipelines—a time-consuming process. By implementing UT equipment with built-in NDT software, the technician can create setups and calibrate the instrument in minutes rather than hours. NDT also software allows inspection parameters to be changed on demand, saving inspection time. 

Aerospace Components

Aerospace manufacturers and operators use ECT to check for cracked bolt holes. Bolt holes may be susceptible to cracking during the manufacturing process and operation due to over-tightening fasteners. However, there is a high potential for false positives caused by burrs, scratches, or other non-critical imperfections. Even worse, noise from these indications can obscure actual defects.

ECT software can help manage signal-to-noise ratio so that technicians can more easily distinguish between burrs or scratches and fine cracks. This can greatly improve the reliability of aerospace bolt hole inspections, which can be critical to flight safety.

See our software solutions for Eddy Current Testing (ECT).

Improving Inspection with Advanced NDT Software

NDT software is growing faster, more powerful, and more user-friendly all the time, and industries are taking notice. The latest software can help simplify the inspection process, analyze data in real-time, and generate 3D visualizations while ensuring the most accurate results possible. Industries that rely on NDT processes should be aware of the software options available to perform faster, more reliable testing.

Zetec offers a wide range of NDT software solutions for UT and ECT inspection requirements. For more information on our NDT software and instrumentation, contact us today.

Eddy Current NDT for Power Busbars

Power busbars are an integral part of heavy-duty power-dependent applications. Busbars are the strip or bar of copper, brass, aluminum, or other metals that help in power distribution by collecting the incoming current and distributing them through the outlet terminals used in high-power spacecraft, wind turbines, and other electrical systems.

Busbars need to be free of defects to ensure proper functioning. Inspection with eddy current (EC) testing before installation and periodically while in use is a helpful way to guarantee their quality. 

Functionality of Power Busbar and Potential Defect Development

Power busbar can be typically found inside switchboards and busway enclosures to help conduct electricity from one electrical terminal to the other. They are assigned a typical voltage, mostly high, and can be found in various sizes and shapes, i.e., bars, strips, and rods.

The busbar acts as a junction from where collection and distribution of power can be made possible; it is composed of conductive materials like copper or aluminum. Different circuits are connected within this junction along the busway rather than branching off of multiple circuits from the main switch. Each power busbar has an isolator and a circuit breaker. The circuit breaker trips when the wiring fault is detected, saving the main switch from being damaged. The damaged busbar can also be easily disconnected and replaced.

Power busbars are cost-effective and durable solutions to wirings. However, material composition and mechanical use of the power busbar can lead to defect development. Under stress and temperature fluctuation due to high current and voltage, fatigue cracks can develop, especially at the bent area. 

This defect can ultimately lead to arching and shorts in the power transmission system. With non-destructive testing (NDT), the power busbar can be examined for possible defects even before the installation. The reliable NDT assessment using EC testing can help massive power generation industries test busbar for surface cracks at different installation and operation phases, thus saving massive repair costs.

Eddy Current Inspection Approach to Power Busbar

In a simple electric panel to large-scale wind generation turbines, the power busbar performs a critical function. Inspecting this component with the advanced eddy current array (ECA) can help prevent failures and potential hazards. 

For a wide range of geometries, the frequency can be optimized in ECA to facilitate greater sensitivity in scanning. With the help of multi-element probes, ECA can inspect larger areas in a single pass as compared to conventional EC testing. In power busbar inspection, surface and near-surface cracks along the surface and bend areas can be simplified with ECA probes which can facilitate:

  • Faster inspection with larger coverage area
  • Flaw detection in varying geometries and orientations
  • 2D or 3D scanning ability
  • Improved defect sizing and data recording capabilities

With advanced eddy current testing solutions from Zetec, power busbar inspection can be made easier.

Learn more about Zetec’s solution for Wind turbine busbar inspection.

Solving Busbar inspection Challenge in Power Generation with NDT

Power busbar is used in almost every application and industry where power is generated. The safety of the power system depends on the quality of the power busbar, which should be free of defects. With Zetec’s solutions, such as Surf-X array probe and MIZ-21C instrument, technicians can easily inspect multiple busbars simultaneously with much more sensitivity and accuracy. 

  • Surf-X Eddy Current Array probe provides flexibility in inspection, which allows assessment of power busbar such as that of wind turbine towers with complex geometries. 
  • MIZ-21C, a portable, handheld instrument provides excellent user interface, display, and data recording capabilities facilitating defect sizing for improved flaw detection in critical applications. 

Quick inspection turnarounds with Zetec’s solution provide an efficient and economic way to ensure the power distribution system operates at its finest. 

Zetec provides portable and flexible ECA instruments that can help serve your NDT needs in the power generation industry with efficient power busbar inspection. Contact Zetec today to create your custom power busbar inspection solution.