Mo14Re合金SPS烧结及室温力学性能

Room Temperature Mechanical Properties of Mo14Re Alloys Obtained by SPS Sintering

摘要:

分别采用高能球磨（high energy ball milling， HEBM）和喷雾干燥-氢气还原（spray drying-hydrogen reduction， SPHR）法制备了钼铼粉体，然后通过放电等离子烧结（spark plasma sintering， SPS）得到Mo14Re合金（Mo14Re-HEBM和Mo14Re-SPHR）。利用X射线衍射仪（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）和背散射电子能谱（EBSD）等分析了Mo14Re合金的物相、显微结构、成分分布和晶粒尺寸，探讨了Mo14Re合金室温拉伸和压缩的变形机理。XRD结果表明Mo14Re-SPHR合金(101)晶面间距小于Mo14Re-HEBM合金；EDS结果显示，Mo14Re-HEBM合金在晶界处存在Re偏聚，而Mo14Re-SPHR合金元素分布均匀；室温压缩结果显示，Mo14Re-SPHR压缩屈服强度为679.11 MPa，高于Mo14Re-HEBM合金的602.71 MPa；EBSD分析发现，压缩变形量大于5.0%时，Mo14Re-SPHR中以｛123｝<111>为主滑移系的晶粒比例增加，以{110}<111>和{112}<111>为主滑移系的晶粒比例降低，而Mo14Re-HEBM中3个滑移系的变化趋势与Mo14Re-SPHR中的相反，使得Mo14Re-HEBM的应变硬化率高于Mo14Re-SPHR；室温拉伸结果显示，Mo14Re-SPHR表现出更好的塑性和韧性。

Abstract:

Mo14Re powders were prepared by high-energy ball milling (HEBM) and spray drying-hydrogen reduction (SPHR), separately. Then, the Mo14Re alloys were obtained by spark plasma sintering (SPS). The phase structure, microstructure, element distribution, and grain size were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). The deformation mechanisms of Mo14Re alloy under room temperature tension and compression were discussed. The XRD results indicate that the (101)-spacing of the Mo14Re-SPHR is smaller than that of the Mo14Re-HEBM. The EDS results show that the segregation of Re is observed at the grain boundary of the Mo14Re-HEBM, while uniform elements distribution in the Mo14Re-SPHR alloy. The room temperature compression results show that the compressive yield strength of the Mo14Re-SPHR is 679.11 MPa, higher than that of the Mo14Re-HEBM (602.71 MPa). EBSD results show that when the compression deformation is larger than 5.0%, the proportion of grains with {123}<111> as the main slip system in Mo14Re-SPHR increases, while the proportion of grains with {110}<111>and {112}<111> as the main slip systems decreases. The change trend of the three slip systems in Mo14Re-HEBM is opposite to that in Mo14Re-SPHR, resulting in a strain hardening rate of Mo14Re-HEBM higher than that of Mo14Re-SPHR. Room temperature tensile results show that Mo14Re-SPHR exhibits better plasticity and toughness.