Interface echo
Phase boundary echo is an acoustic reflection effect at the interface between two different materials in ultrasonic testing. It helps detect liquids, gases, or other material changes.
Physicochemical mechanism of action
A phase boundary echo occurs when an acoustic wave pulse is reflected at the interface between two media with different densities and elasticities. The reflection is strong when the impedance difference is large.
Metallurgical relevance & risks in welding
In ultrasonic testing of weld areas, phase boundary echoes can be indicators of liquids, gases, or incomplete fusion. These can lead to cracks, porosity, or other defects and must therefore be precisely identified.
Workshop practice & instructions
When performing ultrasonic testing, it is important to carefully analyze phase boundary echoes. A high reflection amplitude can indicate liquids or gases. In cases of suspicion, additional testing should be carried out to ensure that no defects are present.