摘要
Ti6Al4V合金广泛应用于航天航空领域多种重要部件的制造,然而其硬度低,仅为高强度钢硬度的60%~70%,严重制约了其推广应用。本工作采用激光熔化沉积技术制备Ti6Al4V合金样品,分析了激光工艺参数对单道熔覆层物相组成、微观组织及显微硬度的影响。物相分析结果表明,柱状晶内部主要由针状α’相组成,β相含量较少;组织尺寸分析结果表明,相较于高能量输入,在低能量输入下针状α’相马氏体组织会更加细小;结合组织尺寸和硬度检测结果分析,硬度性能受针状α’相尺寸影响,随扫描速度的增加或激光功率的减小硬度性能呈现增大趋势,在1200~1600 W的功率范围内,硬度性能不仅受组织尺寸影响,还受气孔缺陷的影响,由于气孔缺陷的产生进一步降低致密度导致硬度性能大幅度下降。在本工作所采用的工艺参数中,在激光功率为1200 W、扫描速度为15 mm/s时得到的试样有最大硬度值415HV,硬度相比Ti6Al4V合金基板提升了27.59%。
Ti6Al4V alloy is widely used tomanufacture many important components in the aerospace field.However,its hardness has only 60%⁃70%of the hardness of high strength steel,which seriously hinders its application.In this paper,Ti6Al4V alloy specimens were printed via laser melting deposition technology.The effects of laser process parameters on the phase composition,microstructure and microhardness of single⁃pass cladding layer were analyzed.The results of the physical phase analysis show that the interior of the columnar crystal is mainly composed of needle⁃likeα'phase,and less content ofβphase.The results of the tissue size analysis show that the martensite tissue of needle⁃likeα'phase were finer at low energy input compared with high energy input.Considering the tissue size and hardness test results,the hardness performance was affected by the size of needle⁃likeα'phase and showed an increasing trend with the increase of scanning speed or the decrease of laser power.In the power range of 1200~1600 W,the hardness properties are not only affected by the tissue size,also by the porosity defects,which further reduce the densities and lead to a significant decrease of hardness properties.Among the process parameters used in this paper,the specimens obtained at a laser power of 1200 W and a scanning speed of 15 mm/s have a maximum hardness value of 415 HV,which is 27.59%higher than that of the Ti6Al4V alloy substrate.
作者
崔志伟
林昕
朱锟鹏
CUI Zhiwei;LIN Xin;ZHU Kunpeng(Key Laboratory for Metallurgical Equipment and Control of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Institute of Precision Manufacturing,Wuhan University of Science and Technology,Wehan 430081,China;Advanced Manufacturing Technology Research Center,Institute of Intelligent Machinery,Hefei Institute of Physical Sciences,Chinese Academy of Sciences,Changzhou 213164,Jiangsu,China)
出处
《材料导报》
CSCD
北大核心
2023年第S02期424-430,共7页
Materials Reports
基金
国家自然科学基金(52175481)。
