扩散连接冶金技术制备无损检测模拟试块的应用研究

将热压扩散连接冶金法应用于超声波模拟试块制备的应用研究,设计制备含有不同深度、宽度的矩形缺陷阵列试块并进行表征研究。利用石墨限位装置实现3～1 mm梯度的3种试块轴向变形极限条件,实施热压扩散连接试验。所制备试块分析结果表明:3种变形极限条件下,试块连接质量均较好,且试块轴向和径向变形量得到不同程度的限制;设计深度为2.0、1.0和0.5 mm的系列缺陷均能保留,预制缺陷的宽/深比小于3.6时,缺陷不会发生熔合;1 mm变形极限下,可获得最为完整的预制缺陷状态。无损检测结果显示各条件下试块预制矩形缺陷边界清晰;微观形貌显示连接界面区域组织扩散熔合充分且无明显影响预制缺陷的自生有害缺陷生成;连接界面区域与基体金相组织无明显区别,且化学元素分布均匀;热压扩散连接冶金方法可以应用于无损检测模拟试块的研制。

Application study on the preparation of nondestructive testing simulated test blocks by diffusion bonding metallurgy

The hot-pressing diffusion bonding metallurgy was applied in the preparation study of ultrasonic simulation test blocks. Some rectangular defect array blocks containing different depths and widths were designed and prepared for the characterization studies. The axial deformation limit conditions of three test blocks with a gradient from 3 mm to 1 mm were realized using graphite limiting device to implement the hot-pressing diffusion bonding tests. The analysis results of the prepared test blocks showed that: the connection quality of the test blocks was good under all three deformation limit conditions, and the axial and radial deformations were restricted to different degrees. The defects of series with design depths of 2.0 mm, 1.0 mm and 0.5 mm could be retained, and the defects would not fuse when the width/depth ratio of the prefabricated defects was less than 3.6. The most completed prefabricated defect conditions could be obtained at deformation limit of 1 mm. The nondestructive testing results showed that the prefabricated rectangular defect of the test block had a clear boundary under various deformation conditions. The microstructure morphology indicated that the diffusion and fusion of the bonding interface area were sufficient, and there was no self-generated harmful defect that obviously affected the prefabricated defect. There was no obvious difference in metallographic structure between the bonding interface area and the substrate, and the distribution of chemical elements was uniform. The method of hot-pressing diffusion bonding metallurgy could be applied for the development of nondestructive testing simulation test blocks.