轧制Mo-14%Re合金的显微组织和室温拉伸性能

Microstructure and Room Temperature Tensile Properties of Rolled Mo-14%Re Alloy

摘要:

为了进一步了解轧制Mo-14%Re合金的显微组织和室温拉伸性能，采用扫描电镜（SEM）和高分辨电子背散射衍射（EBSD）研究了轧制Mo-14%Re合金的显微组织和断口形貌。采用Channel 5软件分析了轧制Mo-14%Re合金在不同退火温度下的组织演变。结果表明，随着退火温度的升高，Mo基体相和ReO₃相的施密特因子逐渐减小。织构强度迅速增加，极图上的晶体取向强度从6.51增加到10.18。轧制Mo-14%Re合金的初始再结晶发生在1100 ℃，在此退火温度下，合金中富稀土ReO₃相均匀析出，导致拉伸过程中应力分布均匀，Mo基体相和ReO₃相表现出明显的晶体取向，ReO₃相晶界主要为大角度晶界，使得断后伸长率达到最大值33.5%。拉伸断裂的韧窝数量最多且最大。此外，还研究了断裂过程中微孔的形成、聚集、生长和裂纹扩展。

Abstract:

Mo-Re alloys have excellent mechanical and processing properties due to their high-temperature resistance, corrosion resistance, and plasticity. To further understand the microstructure and room temperature tensile properties of rolled Mo-14%Re alloy, the microstructure and fracture morphology of the Mo-14%Re alloy were investigated by scanning electron microscopy (SEM) and high-resolution electron backscatter diffraction (EBSD). Channel 5 software was used to analyze the microstructure evolution of rolled Mo-14%Re alloy at different annealing temperatures. With the increase in annealing temperature, the Schmidt factor of the Mo matrix phase and ReO₃ phase decreases gradually. The texture intensity increases rapidly, and the crystal orientation intensity of the polarography increases from 6.51 to 10.18. The initial recrystallization of the rolled Mo-14%Re alloy occurs at 1100 °C, at which the uniform precipitation of the earth-rich ReO₃ phase in the alloy leads to uniform stress distribution during tensile process, the grains of Mo matrix phase and ReO₃ phase show obvious ＜101＞ crystal orientation and ＜111＞ crystal orientation, and the grain boundaries of ReO₃ phase are mainly high-angle grain boundaries, which makes the elongation after fracture reach the maximum of 33.5%. The tensile fracture has the highest number of dimples and the largest size. Besides, the formation, aggregation, growth, and crack propagation of micropores during fracture were studied.