The traditional conditional radiography testing, which is the main testing technology of welding seam,
can not gain the size and position in the welding seam height. Therefore the disadvantage increases the workload of e鄄
liminating flaw and affects repairing welding quality. The phased array ultrasonic technology can detect flaw size and
position by flaw echo wave. The positioning technology of reference test pieces and aluminum alloy melting welding
seam is studied by the Ominsacn MX phased array ultrasonic and 5L64-A2 detector. The research result, microscopic
measurement and macroscopic measurement are contrasted. The result shows that measurement of phased array ultra鄄
sonic, microscopic and macroscopic is uniform, thus the phased array ultrasonic can be used to detect the flaw posi鄄
tion of aluminum alloy melting welding seam