热循环对CuW/CuCr界面强度及CuCr合金性能的影响

Influence of thermal cycling on interfacial bond strength of integrated CuW /CuCr material and properties of CuCr alloy

采用立式烧结熔渗法制备的CuW/Cu0.89wt%Cr整体材料经固溶时效处理后,对其在不同热循环条件下的结合面强度进行了研究。结果表明,在室温～500℃温度范围内,随着热循环次数的增加,整体材料的结合面强度和CrCu端合金显微硬度略有提高。而在室温至600℃热循环温度区间内,结合强度和CuCr合金显微硬度随热循环次数的增加而下降。对不同热循环条件下CuCr端合金组织的研究表明,上限温度为500℃时,晶粒没有发生再结晶现象,析出相面心立方的Cr相非常细小、分散,且与Cu基体保持良好的共格关系;而当热循环上限温度为600℃时,晶粒发生了再结晶长大,析出相明显粗化,此时析出的体心立方的Cr相已与Cu基体失去完全共格关系。

After solution-aging treatment, the effects of thermal cycling on interracial bond strength of integrated CuW/Cu-0.89wt% Cr materials fabricated by sintering-infiltration technique were investigated. In the thermal cycling temperature range from room temperature （RT） to 500℃, the interracial bond strength of the integrated materials and microhardness of Cu-0. 89wt% Cr alloy increase slightly with increasing thermal cycling times, but at RT - 600℃ , the bond strength and the hardness decrease with increase of thermal cycling times. Microstructure of the Cu-Cr alloy side of integrated materials after undergoing different thermal cycling was examined by OM and TEM. The results show that the recrystallization does not occur, finer and dispersed precipitates of Cr with fcc lattice are fully coherent with Cu matrix when the upper limit temperature of thermal cycling is 500℃. However, the phenomena of recrystallization and grain growth is observed, the precipitated Cr particles with bee crystal structure are coarsened distinctly and loses coherency with Cu matrix when the upper limit temperature reaches to 600 ℃.