摘要
采用粉末冶金工艺(混合元素法+冷等静压成形法+真空烧结法)制备了Ti-6Al-4V-x Si合金,并通过光学显微镜(OM)、XRD、SEM和TEM对其组织进行观察分析,结果表明:合金组织中主要为α+β相,伴随有硅化物Ti5Si3析出。第二相Ti5Si3在晶界处的析出可以阻止晶粒长大;作为形核中心,晶粒中的Ti5Si3可以提高晶核形成率,从而起到细化晶粒的作用,提高合金的力学性能。运用精密万能试验机进行力学性能测试,发现当Si元素含量少于0. 5%时,随着合金中Si元素含量的增加,合金组织细化,位错密度增加,使合金的抗拉强度和伸长率明显提高;当Si含量为0. 5%时,合金的抗拉强度达到峰值601 MPa,比未添加Si元素时抗拉强度提高了38. 5%,伸长率提高了25. 3%。
Ti-6Al-4V-xSi alloy was prepared by powder metallurgy process(mixed element,cold isostatic pressing and vacuum sintering).The microstructure of the alloy was observed and analyzed by means of optical microscope(OM),XRD,SEM and TEM.The results show that the microstructure is mainly composed of homogeneousα+βphase with the precipitation of silicide Ti5 Si3.The precipitation of the second phase Ti5 Si3 at grain boundary can prevent grain growing.As the nucleation center,Ti5 Si3 in the grain can improve the nucleation rate,refine the microstructure and improve the mechanical properties of the alloy.The mechanical properties were tested by using the precision universal testing machine and it is found that when Si content is less than 0.5%,the microstructures of the alloy are refined and the dislocation density increases with the increase of Si content in the alloy,so that the tensile strength and elongation of the alloy are obviously improved.When the Si content is 0.5%,the tensile strength of the alloy reaches a peak value of 601 MPa,which is 38.5%higher than that without Si element,and the elongation is 25.3%higher.
作者
郭雷明
王文焱
谢敬佩
赵轩玮
邵昌
刘亚洲
张淼斐
GUO Lei-ming;WANG Wen-yan;XIE Jing-pei;ZHAO Xuan-wei;SHAO Chang;LIU Ya-zhou;ZHANG Miao-fei(School of Material Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Collaborative Innovation Center of Nonferrous Metals,Henan Province,Luoyang 471023,China;Zhengzhou Research Institute of Mechanical Engineering Co.,Ltd.,Zhengzhou 451000,China;Xinjiang Min Long Wear Resistant Material Co.,Ltd.,Kuitun 833200,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2019年第6期148-156,共9页
Journal of Plasticity Engineering
基金
军工“863”项目(2011412-1)
