Phased array and wedge

Types of phased array and wedge

Phased array ultrasonic testing (PAUT) involves using an array of ultrasonic transducers controlled by a phased array device to inspect components for volumetric defects. In contrast, wedges are used in ultrasonics to couple the probe to the test material. These wedges might be made of plastic, rubber, or polyurethane, which are essential in ultrasonic testing.

• Wedge

  The function of the ultrasonic testing wedge is to provide an angle of incidence for an effective examination of the material. It allows for the appropriate refraction of ultrasound waves into the test material. Wedges enhance coupling between the transducer and the test surface, reducing dead zones. This enables better detection of defects. Wedges also serve to protect the transducer from wear and environmental damage. They act as a buffer to preserve the transducer's integrity and longevity. Wedges can be finely shaped to meet the particular geometries and requirements of various inspection scenarios.

• Phased array

  Several small fixed-element ultrasonic transducers make up the phased array. Each transducer generates an ultrasonic pulse that is transmitted to the test object. The phased array uses sophisticated electronic systems to control the firing sequence and time delays among the transducers. By altering the delay time and sequence, the transant can electronically steer or scan the ultrasonic beam in different directions. This enables the phased array to produce images with high angular resolution. It can also capture a wide coverage area. Some advantages of phased arrays include improved defect detection through increased spatial resolution, the ability to visualize and image flaws, rapid inspection speed owing to electronic scanning, and flexibility in probe and scan plan adjustments for different scenarios.

Specifications and maintenance of phased array and wedge

Specifications

• Wedge probes are typically designed to operate within a specific frequency range, commonly between 2.25 and 10 MHz. Higher frequencies may offer better resolution, while lower ones might penetrate deeper.

• For phased array probes, the quantity of individual elements can differ. Some may have as few as 8 elements, while others might boast over 64. Typically, more elements lead to enhanced resolution and versatility.

• The diameter of the wedge probe's acoustic head can vary. Common sizes include small transducers, with a head diameter of around 0.25 to 0.5 inches for general applications, and larger heads (2-4 inches) for specific tasks like weld inspections or thicker materials.

• Wedges are made with specific beam angles, which are crucial for determining the direction of the sound waves transmitted into the test material. Common refracting materials include Plexiglas and Lucite. The angles vary based on the geometry of the wedge.

• Particularly for phased array wedges, the spacing between elements affects resolution and lateral coverage. In many cases, an element spacing of 0.5 inches is standard, but this can vary based on the specific application requirements.

Maintenance

• Cleaning:

  Using a soft cloth and a mild detergent, gently clean the wedge's surface. This will ensure that no residual liquid or debris remains on it. After cleaning, let it dry naturally, or use compressed air to dry the water on the surface faster.

• Storage:

  Put the wedge probe into its protective case when it's not in use. Ensure that the storage environment is dry and that the storage temperature doesn't exceed the maximum limit.

• Regular Inspections:

  Check the connecting cable and the housing of the wedge probe. If any damage is found, repair it promptly to prevent further damage.

Application scenarios of phased array and wedge

A phased array ultrasonic testing device is mainly used in the aerospace, oil and gas, power generation industries. Here are some application scenarios where the devices and their wedges are applied:

• Weld inspections

  Defects in welds can pose a safety threat when they go unnoticed. Welds are generally subject to extreme loads, high pressures, and temperatures. A phased array ultrasonic testing machine is ideal for reliable detection of defects like lack of fusion, cracks, and porosity in welds. The devices can be used on various structures like pipelines, pressure vessels, and structural components.

• Curved components

  Curved components are commonly found in power plants, aerospace, and automotive industries. Examples are turbine blades, pipe probes, and pressure vessel headers. Such components have complex geometries that make them hard to inspect with traditional methods. A phased array device can easily inspect such components and reveal any flaws in the curved geometries.

• Composite materials

  Phased array technology is effective in detecting irregularities in composite materials in real time. It can find outlay delaminations, voids, and fiber misalignments before they develop into bigger issues. The technology works well in scenarios where composite materials are used, such as aerospace, automotive, and civil engineering industries.

• Asset integrity management

  Many industries have to deal with the challenges of managing asset integrity. Examples include the oil and gas industry, chemical processing, and power generation, to mention but a few. A phased array ultrasonic testing device can ease the burden of managing asset integrity. It can do periodic inspections of critical components. The device reveals structural degradation caused by cracking, corrosion, and other defects. Early detection of such damages prolongs the asset's life and improves safety on the premises.

• Research and development

  Phased array technology continues to evolve thanks to ongoing research and development. Innovations in the devices boost their capabilities and enhance resolution and control. Furthermore, new applications of the technology are being unveiled regularly.

How to Choose Phased Arrays and Wedges

• Determine Needs

  Businesses should first be clear about their own testing needs in order to select suitable phased array systems or wedge transducers. Considerations about the types of materials and structures that need to be inspected, the sizes and shapes of the inspection targets, as well as the desired detection resolutions and sensitivities should all be included.

• Focus on Versatility

  Industrial buyers need to choose phased array systems with versatile performances, as well as wedge transducers with various configurations, in order to meet their future inspection requirements as much as possible. This also enables businesses to avoid frequently purchasing new equipment, thereby reducing long-term operating costs.

• Pay Attention to Software

  Instruments equipped with advanced analysis and imaging techniques are essential for enhanced data interpretation and visualization. Automated reporting capabilities can also improve operational efficiency and ensure consistency in inspection procedures.

• Ensure Equipment Integration

  Consider equipment's compatibility and integration with existing testing equipment to ensure seamless data exchange and workflow optimization.

• Focus on Technical Support

  Pay attention to the supplier's technical support and after-sales service to ensure timely assistance and equipment maintenance when needed.

Phased array and wedge FAQ

Q1: What is the difference between phased array and conventional ultrasound?

A1: In phased array ultrasonic testing, multiple small diameter beams are used instead of a single large diameter beam. The ability to steer and sweep these beams offers advantages in scanning speed, coverage, and enhanced detection of flaws and characterization of materials.

Q2: What is the difference between phase array transducers and linear transducers?

A2: Linear transducers, such as those used in conventional ultrasound, employ a single large crystal or group of crystals to produce a sound wave in a straight line. In contrast, phased array transducers feature numerous small crystals that can be sequentially pulsed, effectively "steering" the sound wave in various directions.

Q3: What are the advantages of wedge-shaped transducer holders?

A3: This design allows for better contact and alignment with curved surfaces, making it ideal for complex geometries. Additionally, the lightweight and low-profile construction of phased array wedges promotes ease of use and maneuverability in field or workshop settings, enhancing inspection efficiency and effectiveness.