6GINZEL E.Materials research institute etc,time-of-flight diffraction and pulse echo line scanning[J].NDT,2000(6):64-68.
7Saka M, Uchikawa T. Simplified NDE of a closed ver- tical crack using ultrasonic [ J ]. NDT&E International, 1995, 28 (5) :289 - 296.
8HART D E, KATZ J M. Ultrasonic measurement of weld penetration [ J ]. Welding Journal, 1984, 63 (9) : 273 - 281.
9Lott L A. Ultrasonic detection of molen/solid inter- faces of weld pools [ J]. Materials Evaluation, 1984, 42:337 - 341.
10Bird C. Quality control of firction slit" welds hy the application of nondestructive testing[ C]. 4'~' International Symposium on Friction Stir Welding. Utah ,USA ,2003 : 14 - 16.
