Vacuum Brazed Aluminum Thermal Plate Inspection and Joint Quality Testing
Vacuum brazed aluminum plate acceptance demands 100 percent inline ultrasonic C-scan inspection and helium leak validation below 10-6 mbar L/s to prevent field coolant leaks.
Pulse-Echo Testing
Meaning
Ultrasonic inspection technique that uses a single transducer to both transmit a sound wave and receive the reflection from internal features. In the context of battery manufacturing, pulse-echo testing identifies delamination between layers or voids in the casing material. This method relies on the timing of the returning signals to calculate the location of a defect.
Signal Timing
Sound waves travel through the material and bounce off the back wall or any internal discontinuity they encounter. During pulse-echo testing, the time of flight between the initial pulse and the received echo determines the depth of the reflecting surface. A shortened return time indicates that the sound hit an obstruction before reaching the far side of the part.
Depth Calculation
Knowledge of the sound velocity in the specific material allows the equipment to convert time into distance. Precision in pulse-echo testing depends on a consistent coupling between the probe and the surface to ensure the maximum amount of energy enters the part. This calculation is used to measure the thickness of battery plates or the depth of a weld bead.
Defect Identification
Characteristics of the echo (such as its height and shape) provide clues about the nature of the internal flaw. Small and sharp reflections suggest a crack, while a loss of the back-wall signal might indicate a large area of porosity that scatters the sound. pulse-echo testing remains the most versatile non-destructive method for checking the health of thick metallic components. The technique provides a clear map of the internal structure of a part without the need for disassembly.