Effect of ternary additions on mechanical properties of TiAl
Effect of ternary additions on mechanical properties of TiAl
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DOI：
10.1016/s1359-6454(97)00422-9
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发表时间：
1998-03-23
期刊：
影响因子：
9.4
通讯作者：
Izumi, O
中科院分区：
文献类型：
--
作者：
Kawabata, T;Fukai, H;Izumi, O
研究了V、Cu、Nb、Zr和Mn等三元合金元素的添加以及化学计量成分向富Al成分的偏离对TiAl合金室温（室温）、873和1073 K真空下力学性能的影响。V、Zr和Mn的添加增加了室温、873和1073 K下的弯曲屈服应力，而Cu的添加仅增加了873和1073 K下的屈服应力。V、Nb、Zr和Mn的加入提高了室温和873 K下的断裂应力。Nb和Mn的加入提高了合金的室温断裂应变。在873 K下，通过与任何三元元素的微合金化通常倾向于增加断裂应变。三元添加剂在873 K时加工硬化速率增加，在1073 K时加工硬化速率降低。在空气中获得的断裂应变的一半左右，在真空中在RT，除了高V添加，这似乎抑制了环境脆性。在10（-5）~ 10（-3）s（-1）范围内，断裂应变随应变速率的增加而增加。弯曲屈服应力、断裂应力和断裂应变随晶粒尺寸平方根d（-1/2）的倒数而增大。断口分析表明，在室温下，在空气和真空中，穿晶解理是主要的断裂类型。在873 K时，沿晶断裂的面积比室温下的大。微合金化元素对力学性能的影响进行了讨论，在晶格参数，晶粒尺寸，测试气氛，应变速率，气态杂质元素和测试温度的变化。(C)1998年冶金学报
The effect of ternary additions such as V, Cu, Nb, Zr and Mn as well as the deviation from the stoichiometric composition to the Al-rich composition on mechanical properties of TiAl was studied at room temperature (RT) in air, and RT, 873 and 1073 K in vacuum. V, Zr and Mn additions increased the bend yield stress at RT, 873 and 1073 K while Cu additions increased the yield stress at 873 and 1073 It only. The fracture stress was increased by the addition of V, Nb, Zr and Mn at RT and 873 K. The RT fracture strain was improved by additions of Nb and Mn. At 873 K by microalloying with any of the ternary elements generally tended to increase the fracture strain. The work hardening rate was increased at 873 K and decreased at 1073 K by the ternary additions investigated. The fracture strains obtained in air were about a half of those in vacuum at RT, except high V addition which seems to suppress the environmental brittleness. The fracture strain increased with increasing strain rate within 10(-5)-10(-3) s(-1). The bend yield and fracture stresses and the fracture strain increased with the inverse of square root of grain size, d(-1/2). Fractography revealed that the transgranular cleavage was a main fracture type in air and in vacuum at RT. At 873 K, the area of the intergranular fracture was larger than that at RT. The effects of microalloying elements on the mechanical properties have been discussed in terms of changes in lattice parameters, grain size, test atmosphere, strain rate, gaseous impurity elements and test temperature. (C) 1998 Acta Metallurgica Inc.