(中南大学 轻质高强结构材料国家级重点实验室，长沙 410083)
摘 要: 以90W-7Ni-3Fe预混粉末和30CrMnSiNi2A钢雾化粉末为原料，采用热等静压技术在1350 ℃、150 MPa、3 h烧结工艺下进行共烧结。利用SEM、XRD、TEM和万能力学试验机等研究了90W-7Ni-3Fe/ 30CrMnSiNi2A共烧结体的微观组织和力学性能特征。结果表明：采用共烧结方法成功制备了90W-7Ni-3Fe/30CrMnSiNi2A结构复合材料，共烧结体组织均匀、致密度高、界面无孔洞和裂纹，结合良好；钨合金和钢基体的相对密度均大于99%，抗拉强度分别为920 MPa和1309 MPa。在钨合金和钢的界面区域发生强烈的元素扩散，形成了厚度为40~50 μm的Fe6W6C相，并分析了Fe6W6C相的形成；硬脆Fe6W6C相的存在恶化钨合金/钢界面的力学性能，界面的抗拉强度为85 MPa。断裂模式为Fe6W6C相和W相的混合断裂。
关键字: 钨/钢结构复合材料；热等静压；粉末共烧结；微观组织；力学性能
（National Key Laboratory of Science and Technology for National Defence on High-strength Structural Materials, Central South University, Changsha 410083, China）
Abstract:90W-7Ni-3Fe premixed powders and 30CrMnSiNi2A steel atomized powder were used as raw materials and co-sintered by HIP at (1350 ℃, 150 MPa, 3 h). The SEM, XRD, TEM and universal mechanical testing machine were used to evaluate the microstructure and mechanical properties of co-sintered samples. The results show that the 90W-7Ni-3Fe/30CrMnSiNi2A composite can be successfully fabricated by co-sintering method. The co-sintered samples shows high density and uniform microstructure, and the interface present good metallurgical bonding free from voids or cracks. The relative densities of 90W-7Ni-3Fe alloy and steel are more than 99%, and their tensile strengths are 920 MPa and 1309 MPa, respectively. The violent element reaction occurs at the interface between 90W-7Ni-3Fe alloy and 30CrMnSiNi2A steel and the Fe6W6C phase with thickness of 40-50 μm forms. In addition, the formation mechanism of Fe6W6C phase was discussed based on the phase diagram theory. The tensile strength of tungsten alloy/steel joint is 85 MPa, and the tungsten/steel composites failed mainly along the interface of tungsten alloy/Fe6W6C, which show Fe6W6C phase brittle fracture and W/W interfacial failure on the fracture.
Key words: tungsten/steel structural composite materials; hot isostatic pressing; co-sintering; microstructure; mechanical property
