How to Use Ultrasound Waves During the Welding of Aluminum to Avoid Cracks

Attach the transducer to the electronic ultrasonic set per manufacturer's instructions. High-frequency, electronic pulses will be produced from the ultrasonic device through the coaxial cable connected to the transducer. Turn the ultrasonic set on by flipping its switch and allow it to calibrate if necessary (use the user manual for the device to determine when it is fully calibrated).

Place the transducer against a smooth, flat surface of the aluminum being tested. The transducer, converting the electrical energy from the ultrasonic set to sound waves, automatically transmits at the velocity for aluminum (6,400 metres.) The sound wave will travel through the aluminum and not return unless it hits a reflector, such as a crack. If there are no cracks, the sound wave will return to the transducer at the same velocity. If there is a flaw within the material, the sound wave will return at a higher speed than 6,400 metres. There is a piezoelectric (quartz) crystal located within the transducer that will convert the returned sound wave into an electronic pulse that travels back to the cathode ray tube of the ultrasonic set. The cathode ray tube displays the results of the test.

Evaluate the results of the test. This should be done by an experienced contractor. This test can be conducted during the welding process to prevent cracks in the finished product. If an error is found, the aluminum can be melted and reformed.