激光直接沉积界面超声反射与力学性能关系研究

Study on Relationship Between Interface Ultrasound Reflection of Laser Direct Deposition and Mechanical Properties

通过对激光直接沉积制备的FGH96粉末高温合金与K441高温合金界面超声回波的研究,分析界面回波高度变化的原因,在不同回波高度位置取样进行室温拉伸性能测试,断口观察并利用EBSD测量K441高温合金的晶粒取向。结果发现,不同回波高度位置取出的试样拉伸性能差异不大,回波高度与拉伸性能无明显相关性,试样回波高度的变化主要是由于K441高温合金粗晶粒取向不同造成的,FGH96粉末高温合金/K441高温合金界面可能产生φ1.2 mm平底孔当量的伪缺陷显示。

Ultrasonic echo of interface between FGH96 powder metallurgy superalloy and K411 alloy manufactured by laser direct deposition was studied. The reason of the variable amplitude of interface reflection was analyzed. Tensile tests were carried out on the specimens taken from position with different ultrasonic reflection at room temperature. The fractures of the specimens were observed and the grain orientation of K441 alloy was measured by EBSD. The results show that tensile performance of the samples from position with different ultrasonic reflection nearly has no change. There is no significant correlation between echo reflection and tensile properties. The amplitude variation of echo reflection is mainly caused by the orientation of K411 alloy grains. The interface of FGH96 powder metallurgy superalloy/K411 alloy may produce pseudo-defect display with equivalent of φ1.2 mm flat bottom hole.