中文摘要：

为了检测新材料性能和评估新制备工艺,利用超声显微无损检测系统和PVDF线聚焦超声探头,对增材制造（3D打印）和粉末冶金2种特种加工试件进行表面波波速测量,用于材料力学性能的反演.利用散焦实验测量和时间分辨法,测量试件截面不同位置、不同角度的表面波波速,获取相应位置和角度下的力学性能参数.实验所用窄探头PVDF薄膜宽度仅为1 mm,通过减少被测面积,提高了探头的分辨率.结果表明：粉末冶金材料在任意方向上的表面波波速基本一致,呈各向同性.3D打印材料不同方向表面波波速略有差异,呈现出一定的各向异性.超声显微无损检测系统可用于材料的小区域、多角度声学性能测试,实现材料力学性能的反演表征,为新材料性能检测、新制备工艺评估提供一种无损检测与评价的方法.

英文摘要：

Based on the acoustic microscopy nondestructive testing system,the surface acoustic wave velocities of two types of special samples that were processed by additive manufacturing（ 3D printing）and powder metallurgy were measured by using line-focusing PVDF transducers,which can be used for the inversion of mechanical properties of materials. The surface wave velocities at different positions and angles were obtained by defocus measurement and time-resolved method. Mechanical properties at the corresponding position and angle were calculated by these surface wave velocities. To improve the resolution of the transducer,the line-focusing PVDF transducer with 1 mm wide film was developed specially to reduce the detection area. Measurement results show that the surface wave velocities in the arbitrary directions are constant for powder metallurgical material, namely isotropy. Surface wave velocities of 3D printing material at different directions are slightly different,showing anisotropy. The acoustic performance of arbitrary angle or small area of materials can be measured by the acoustic microscopic nondestructive measurement system, which is used to inverse the material mechanical properties with high precision and reliability. It provides a nondestructive testing and evaluation method for performance test of new materials and the assessment of new processing.