Microstructures and mechanical properties of Nb-32Ti-7Al alloys containing different V and Zr contents were investigated. The microstructures were characterized using optical microscopy and scanning electron microscop...Microstructures and mechanical properties of Nb-32Ti-7Al alloys containing different V and Zr contents were investigated. The microstructures were characterized using optical microscopy and scanning electron microscopy (SEM). The alloy with V and Zr presents single phase Nb solid solution (Nbss). Tensile testing was carried out at room temperature and 1373 K. The results show that these alloys have good ductility at room temperature. The strengths at room and high temperature increase with the addition of V and Zr, but the room temperature ductility decrease.展开更多
激光定向能量沉积(laser-directed energy deposition,LDED)成形Ti-Al合金的微观组织通常表现为贯穿多个熔池的粗大柱状晶,使得该合金较难获得均匀的力学性能。本文选用Nb作为Ti-Al二元合金的添加元素,通过LDED技术成形一系列Ti-6Al-x N...激光定向能量沉积(laser-directed energy deposition,LDED)成形Ti-Al合金的微观组织通常表现为贯穿多个熔池的粗大柱状晶,使得该合金较难获得均匀的力学性能。本文选用Nb作为Ti-Al二元合金的添加元素,通过LDED技术成形一系列Ti-6Al-x Nb(x=5、6.5、7.5,质量分数)三元合金,采用光学显微镜、X射线衍射仪、扫描电镜和电子背散射衍射仪对合金的微观形貌、室温拉伸性能以及变形机制进行研究,探究Nb含量对LDED成形Ti合金微观组织及拉伸性能的影响。结果表明:不同Nb含量合金的微观组织形貌较为接近,均主要由细长的针状或片层状α/α′相组成,且存在少量的残余β相。当Nb质量分数为6.5%时,合金具有最高的极限抗拉强度((902±35)MPa)和屈服强度((849±20)MPa),这主要归因于晶粒尺寸的减小。此外,随Nb含量增加,合金的伸长率逐渐降低。当Nb质量分数为7.5%时,合金的伸长率最低,为(10.2±1.4)%。展开更多
文摘Microstructures and mechanical properties of Nb-32Ti-7Al alloys containing different V and Zr contents were investigated. The microstructures were characterized using optical microscopy and scanning electron microscopy (SEM). The alloy with V and Zr presents single phase Nb solid solution (Nbss). Tensile testing was carried out at room temperature and 1373 K. The results show that these alloys have good ductility at room temperature. The strengths at room and high temperature increase with the addition of V and Zr, but the room temperature ductility decrease.
文摘激光定向能量沉积(laser-directed energy deposition,LDED)成形Ti-Al合金的微观组织通常表现为贯穿多个熔池的粗大柱状晶,使得该合金较难获得均匀的力学性能。本文选用Nb作为Ti-Al二元合金的添加元素,通过LDED技术成形一系列Ti-6Al-x Nb(x=5、6.5、7.5,质量分数)三元合金,采用光学显微镜、X射线衍射仪、扫描电镜和电子背散射衍射仪对合金的微观形貌、室温拉伸性能以及变形机制进行研究,探究Nb含量对LDED成形Ti合金微观组织及拉伸性能的影响。结果表明:不同Nb含量合金的微观组织形貌较为接近,均主要由细长的针状或片层状α/α′相组成,且存在少量的残余β相。当Nb质量分数为6.5%时,合金具有最高的极限抗拉强度((902±35)MPa)和屈服强度((849±20)MPa),这主要归因于晶粒尺寸的减小。此外,随Nb含量增加,合金的伸长率逐渐降低。当Nb质量分数为7.5%时,合金的伸长率最低,为(10.2±1.4)%。
