合金元素对Laves相增强Nb基合金的相组成与力学性能的影响  

Effects of Alloying Element Additions on the Phase Transformation and Mechanical Properties of Laves Phase Reinforced Nb Matrix Composites

作　　者：肖璇[1] 鲁世强[1] 董显娟[1] 黄铭刚[1] 刘俊伟[1] 

机构地区：[1]南昌航空大学,江西南昌330063

出　　处：《稀有金属材料与工程》2013年第3期560-564,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50474009);江西省自然科学基金(0350045);江西省教育厅青年科学基金(GJJ10179);南昌航空大学博士科研启动基金(EA200906169)

摘　　要：采用机械合金化与热压烧结工艺制备了添加合金元素V和Fe的Laves相增强的Nb基复合材料。研究了添加质量分数4%V和Fe的Nb/NbCr2-4.0V和Nb/NbCr2-4.0Fe配比成分的元素粉,经MA20h后在1250℃热压30min所获得的Nb/NbCr2合金的组织和性能。结果表明:在热压过程中原位合成出细小弥散分布的三元Laves相Nb(Cr,V)2和Nb(Cr,Fe)2,并且V和Fe原子只占据Laves相中的Cr原子位置。制备出的Laves相增强Nb基合金接近全致密,组织细小均匀,晶粒尺寸小于500nm。Nb/NbCr2-4.0V和Nb/NbCr2-4.0Fe合金的断裂韧性分别达到5.3和6.3MPa·m1/2,其中Nb/NbCr2-4.0Fe合金不仅抗压强度达到2256MPa,其屈服强度和塑性应变也分别达到2094MPa和6.03%。The Laves phase reinforced Nb matrix composite materials with V and Fe additions were prepared by mechanical alloying and reactive hot pressing.Microstructures and properties were investigated of Nb/NbCr2 alloys prepared from 20 h mechanically alloyed powders of Nb/NbCr 2-4.0V and Nb/NbCr 2-4.0Fe stoichiometric compositions by hot pressing at 1250 ℃ for 30 min.The results indicate that the fine dispersed ternary Laves phase Nb（Cr,V）2 and Nb（Cr,Fe） 2 are synthesized in the Nb matrix by the in-situ reaction synthesis technique during hot pressing.In the ternary Laves phase V and Fe atoms preferentially occupy the Cr sites.The prepared Laves phase reinforced Nb matrix alloys with fine and uniform microstructures are nearly full-dense,and their grain sizes are less than 500 nm.The Nb/NbCr2-4.0V and Nb/NbCr 2-4.0Fe alloys have fracture toughnesses of 5.3 and 6.3 MPa·m 1/2 respectively.Furthermore,the Nb/NbCr2-4.0Fe alloy has a yield strength of 2094 MPa,compressive strength of 2256 MPa and plastic strain of 6.03%.

关 键 词：机械合金化 热压 Laves相NbCr2 Nb基复合材料 组织与性能 

分 类 号：TG146[一般工业技术—材料科学与工程]