微量Cr对93W-Ni-Fe合金组织及力学性能的影响

Effect of minor Cr additions on microstructure and mechanical properties of 93W-Ni-Fe alloys

研究了Cr元素对93W-4.9Ni-2.1Fe高密度合金性能和微观结构的影响,并探讨固溶淬火工艺对添加微量Cr的93W-Ni-Fe合金微观结构及力学性能的影响。实验采用光学金相、扫描电镜和能谱等对烧结态、固溶淬火态样品的组织形貌进行表征,采用准静态拉伸实验对合金的拉伸强度和伸长率进行测试,采用阿基米德排水法对合金的相对密度进行测试。结果表明:随着Cr含量(质量分数)由0增加到1.5%,烧结态93W-Ni-Fe合金的拉伸强度、相对密度、伸长率分别由997.2MPa、99.27%和14.94%降至834.7MPa、95.21%和5.69%。随着Cr含量由0增加到1.5%,固溶淬火态93W合金的拉伸强度、相对密度、伸长率分别由1039MPa、99.33%和18.37%降至888.5MPa、96.10%和7.39%;Cr元素与W、Ni、Fe、O等元素在93W-Ni-Fe合金中生成富Cr固溶体,并在合金界面上形成偏聚,降低93W-Ni-Fe合金界面的结合强度,导致合金的力学性能降低。

The effects of solid solution quenching and element chromium additions on the properties and microstructure of 93W-4.9Ni-2.1Fe alloy were investigated deeply. Optics microsccopy（OM）, scanning electricity microsccopy（SEM） and EDAX energy spectrum were used to study the microstructure and compositions of the alloys, respectively. The strength and elongation of alloys were tested with quasi-static tensile testing machine, and the relative densities of the alloys were measured by Archimedes method. The results indicate that when the Cr content （mass fraction） increases from 0 to 1.5%, the tensile strength, relative density and elongation of 93W-Ni-Fe alloy reduce from 997.2 MPa, 99.27% and 14.94% to 834.7 MPa, 95.21% and 5.69%, respectively. Meanwhile, with the Cr content increases from 0 to 1.5%, the tensile strength, relative density and elongation of solid solution quenching 93W-Ni-Fe alloy reduce from 1 039 MPa, 99.33% and 18.37% to 888.5 MPa, 96.10% and 7.39%, respectively. Elements Cr, W, Ni, Fe and O form Cr-rich solid solutions and gather along the interfaces of the alloys, which result in reducing the mechanical properties of 93W-Ni-Fe alloys.