ZrC含量对钨材料组织和性能的影响

Effect of ZrC Content on Microstructure and Properties of Tungsten Materials

采用＂溶胶-非均相沉淀-喷雾干燥-热还原＂制备了W-ZrC复合粉末,经氢气保护气氛高温烧结后制备出W-ZrC材料,研究了ZrC含量对W的力学性能和显微组织的影响。结果表明,W-ZrC材料的相对密度较纯W材料得到很大提高,其室温抗拉强度由粉末烧结态纯W的290 MPa可提高至543 MPa,材料的应变由1.7%增大至3.5%;ZrC第二相粒子作为障碍能有效阻碍钨晶界的移动,由纯W晶粒的100μm左右细化至10~15μm;纯W的断口形貌主要为沿晶解理断裂,添加ZrC第二相粒子后断口组织中出现了穿晶解理断裂,说明ZrC能够有效强化W的晶界强度,并起到良好的细晶强化和弥散强化作用。

W-Zr C composite powders were prepared by sol-heterogeneous precipitation-spray drying-thermal reduction technology. Then W-Zr C material was prepared by high temperature sintering under hydrogen atmosphere. Effects of Zr C content on the microstructure and properties were investigated. The results show that the relative density of W-Zr C material is greatly improved compared with that of pure W, and the room temperature tensile strength of W-Zr C material, 543 MPa is almost twofold of 290 MPa of pure W. And the strain of the material is increased from 1.7% to 3.5%. The second phase particles of Zr C can effectively prevent the migration of W grain boundary. The grains are refined from 100 μm to 10~15 μm. The fracture morphology of pure W is mainly intergranular fracture, while the transgranular brittle fracture occurs in W-Zr C materials. Zr C can effectively enhance the strength of the grain boundary of W, and has a good effect in fine grain strengthening and dispersion strengthening.