Scanning acoustic microscopy (SAM) is used to characterize welds in a thermoplastic polymer (ABS) manufactured by injection-molding, particularly at the locations of weld-lines known to form as unavoidable significant defects. Acoustic micrographs obtained at 420 MHz clearly resolve the weld lines with morphological deformations and microelastic heterogenity. This is also where terahertz (THz) measurements, carried out in support of the SAM study, reveal enhanced birefringence corresponding to the location of these lines enabling verification of the SAM results. Rayleigh surface acoustic waves (RSAW), quantified by V(z) curves (with defocusing distance of 85 μm), are found to propagate slower in regions close to the weld lines than in regions distant from these lines. The discrepancy of about 100 m/s in the velocity of RSAW indicates a large variation in the micro-elastic properties between areas close to and distant from the weld lines. The spatial variations in velocity (V_R) of RSAWs indicate anisotropic propagation of the differently polarized ultrasonic waves.

扫描声显微镜（SAM）用于表征通过注模法制造的热塑性聚合物（ABS）中的焊缝，特别是在已知形成不可避免的重大缺陷的焊缝处。在420 MHz处获得的声学显微照片清楚地分辨了具有形态变形和微弹性异质性的焊缝。这也是在SAM研究的支持下进行的太赫兹（THz）测量的结果，与这些线的位置相对应的双折射得到了增强，从而可以验证SAM结果。瑞利表面声波（RSAW），由V（z）曲线（散焦距离为85μm）在靠近焊接线的区域比在远离这些线的区域传播更慢。RSAW速度大约有100 m / s的差异表明，在靠近和远离焊缝的区域之间，微弹性特性有很大的差异。RSAW的速度（V _R）的空间变化表明不同极化的超声波的各向异性传播。