热压烧结制备高Nb-TiAl合金烧结工艺研究

摘要

以Ti-45Al-8Nb-0.2B-0.2W-0.1Y元素粉末为原料,采用真空热压烧结工艺制备了高Nb-TiAl合金。结果表明,烧结温度对合金的显微组织影响显著,当烧结温度高于1350℃时,可制备出致密度高、晶粒尺寸在20~30μm间的全片层组织高Nb-TiAl合金；提高烧结温度可促进Nb在基体相中的扩散,有助于加强Nb的固溶强化效果；合金的室温力学性能与显微组织密切相关,当烧结温度为1350℃时,其显微硬度为744.5 HV 0.1/15,抗弯强度为674 MPa,显示出较好的室温力学性能。%Using the Ti-45Al-8Nb-0. 2B-0. 2W-0. 1Y element powder as raw material,the high Nb-TiAl alloy was prepared through vacuum hot pressing sintering process. The results show that the sintering temperature has significant influence on alloy microstructure, when the sintering temperature higher than 1 350 ℃, the film layer high-TiAl alloy with high density, grain size between 20 ~ 30 microns can be prepared;Improving the sintering temperature can promote the diffusion of Nb in the matrix phase,which can help to strengthen the solid solution strengthening effect of Nb;the mechanical properties of alloy at room temperature is closely related to its microstructure, when the sintering temperature at 1 350 ℃,the microhardness of 744. 5 HV0. 1/15,bending strength of 674 mpa,showing a good mechanical properties at room temperature.