Improvement of the Probe for Lamb Wave On-line Ultrasonic Testing to Detect Inclusions in the Strip of Aluminium Can Stocks

摘要

The remarkable improvement of Lamb wave ultrasonic wheel probe which provides good performance of inspection of nonmetallic inclusions in aluminium can stocks is described. Lamb wave ultrasonic testing by only line scan has excellent capability to be suitable for on-line testing. Fundamental Lamb wave properties obtained from basic experiments using wheel probe have given us technical improvement points like an increase of Lamb wave frequency, a choice of optimal transducer material, an increase of amplifier gain, setting of optimal Lamb wave beam direction and dynamic stabilization of wheel probe motion. The equipment which incorporated above technologies was made as an experiment. This equipment is able to detect 50-80mum diameter nonmetallic inclusions in the aluminium thin strip.