激光立体成形Ti-80%Ni合金显微组织及力学性能

来源期刊：金属学报2010年第9期

论文作者：许小静 林鑫 黄卫东 王亮

文章页码：1081 - 1085

关键词：Ti-80%Ni； 激光立体成形； 工艺参数； 微观组织； 力学性能

Key words：Ti-80%Ni； laser solid forming(LSF)； laser processing parameter； microstructure； mechanical property

摘    要：采用激光立体成形技术制备了Ti-80%Ni(质量分数)合金,研究了工艺参量对显微组织和力学性能的影响.结果表明,激光立体成形Ti-80%Ni合金由η-TiNi₃板条和TiNi(B2)+η共晶构成.随着激光扫描速率的增大,η板条逐渐转变为η板条+(TiNi(B2)+η)共晶,η板条尺寸随着扫描速率的增大而减小;随着激光功率的增大,共晶体积分数逐渐增大,η板条逐渐碎断转变为一定取向的块状组织,功率越大,块状组织越细,形成(TiNi(B2)+η)离异共晶组织+板块间(TiNi(B2)+η)共晶组织.激光扫描速率和激光功率的增大均导致硬脆η板条含量减少,合金的成形性和塑性增加.

Abstract: Ti-80%Ni alloy was prepared by laser solid forming (LSF) under different processing parameters.The microstructure of the alloy consists ofη-TiNi₃ phase under low scanning rate v and power P.With the increase of scanning rate,TiNi(B2)+η eutectic appeared,and with the increase of laser power,ηlaths were broken into bulks and distributed along certain orientation,and (TiNi(B₂)+η) devoiced eutectic+inter-lath (TiNi(B2)+η) eutectic appeared.The higher the power is,the finer theηbulks are.And the enhanced power leads to a growing up of(TiNi(B2)+η) eutectic volume fraction. The microstructure became much fine with increasing v and P,while the volumn fraction of hard-brittleηlath decreased,as a result,the laser formability and plasticity of Ti-80%Ni both increased.