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在氩气保护下 ,利用非自耗钨极水冷铜坩埚电弧熔炼法制备 Ti-Si共晶合金 ,并研究其组织与性能。 X射线衍射结果 ,室温下铸态 Ti-Si合金的组织由α-Ti基体和金属间化合物 Ti5Si3两相组成 ,具有非平衡凝固特征。Miedema理论计算说明 ,Ti5Si3相的生成热比高温下 β-Ti的生成热更小 ,共晶反应时 Ti5Si3相先析出。首次测得 Ti-Si共晶系合金的压缩强度和塑性 ,分析断口特征发现 ,不同共晶类型的 Ti-Si合金虽然都属于脆性断裂 ,但断裂机制不尽相同
The Ti-Si eutectic alloy was prepared by arc melting with non-consumable tungsten water-cooled copper crucible under argon gas protection and its microstructure and properties were studied. X-ray diffraction results showed that the microstructure of as-cast Ti-Si alloy at room temperature consisted of two phases of α-Ti matrix and intermetallic compound Ti5Si3, which had the characteristics of non-equilibrium solidification. The Miedema theoretical calculation shows that the heat of formation of Ti5Si3 phase is smaller than the formation heat of β-Ti at high temperature, and the Ti5Si3 phase is precipitated first in the eutectic reaction. The compressive strength and plasticity of the Ti-Si eutectic alloy were measured for the first time. The fracture characteristics were analyzed. The Ti-Si alloys with different eutectic types belong to the brittle fracture, but the fracture mechanisms are different