工程科学学报，第41卷，第2期：238-245,2019年2月 Chinese Joural of Engineering,Vol.41,No.2:238-245,February 2019 DOI:10.13374/j.issn2095-9389.2019.02.011;http://journals.ustb.edu.cn 医用镍钛合金的制备与热压缩变形行为 王 臻)，徐效文)四，王快社)，王文2) 1)中南大学生物医学工程系，长沙4100832)西安建筑科技大学治金工程学院，西安710055 区通信作者，E-mail:xuxiaowen@csu.edu.cn 摘要采用真空感应熔炼法制备了医用T-50.7%N合金（原子数分数），测试了铸态合金的成分、相变点、微观组织和硬 度，并采用Gleeble-3800热模拟实验机在变形温度750-950℃、应变速率0.001-1s',应变量为0.5的条件下对Ni-Ti合金 进行高温压缩变形，分析其流动应力变化规律，建立了高温塑性变形本构关系和热加工图.结果表明：当变形温度减小或应变 速率增大时，N-Ti合金的流动应力会随之增大.应变速率为1s时，合金的真应力-真应变曲线呈现出锯齿状特征.根据热 加工图，获得了N-T合金的加工安全区和流变失稳区，进而确定其合理的热变形温度范围为820~880℃，真应变速率低于 0.1s·.从而为制定镍钛合金的锻造工艺参数提供理论和数据基础. 关键词镍钛记忆合金：热压缩变形；应变曲线：热加工图 分类号TG174 Preparation and hot compression deformation of biomedical Ni-Ti alloy WANG Zhen'),XU Xiao-wen),WANG Kuai-she2),WANG Wen2) 1)Department of Biomedical Engineering,Central South University,Changsha 410083,China 2)School of Metallurgy Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China Correspondent author,E-mail:xuxiaowen@csu.edu.cn ABSTRACT A Ti-50.7%Ni atomic fraction)shape alloy was prepared by vacuum induction melting under dynamic argon atmos- phere.By analyzing the composition,deformation temperature,microstructure,and hardness of the as-cast Ni-Ti shape alloy in this study,it was found that the properties of the as-cast Ni-Ti alloy met the medical standard.To analyze the variation law of the flow stress,the flow stress of the compression deformation for as-cast Ni-Ti alloy was studied by high-temperature compression with a Gleeble-3800 simulated machine within a deformation temperature range of 750-950C,strain rate range of 0.001-1.0s,and strain level of 0.5.To analyze the relationship between variables in the hot deformation process of as-cast Ni-Ti alloy,a constitutive equation based on dynamic material model was established.To determine the reasonable range of hot working conditions for as-cast Ni-Ti alloy deformation,hot processing maps under different hot deformation conditions were set up.The results show that when the deformation temperature decreases or strain rate increases,the flow stress of as-cast Ni-Ti alloy increases.This phenomenon shows that the main factors affecting the flow stress of as-cast Ni-Ti alloy are deformation temperature and strain rate.When the strain rate is 1.0s,the true stress-true strain curves of as-cast Ni-Ti alloy exhibits a zigzag feature.This is mainly attributed to the alternation between hard- ening and softening during deformation.According to the hot processing maps under different hot deformation conditions,the processing zone and unstable hot deformation region of the as-cast Ni-Ti alloy were obtained.Then,the best temperature range of hot deformation is determined as 820-880C,and the true strain rate is less than 0.1s.This study provides a theoretical and data basis for the de- velopment of forging process parameters of Ni-Ti alloy. KEY WORDS Ni-Ti alloy;hot compression;strain curves;hot processing map 收稿日期：2018-06-07 基金项目：甘肃省科技重大专项计划“镍产业链关键技术开发与产业化”资助项目(17ZD2GC011)工程科学学报,第 41 卷,第 2 期:238鄄鄄245,2019 年 2 月 Chinese Journal of Engineering, Vol. 41, No. 2: 238鄄鄄245, February 2019 DOI: 10. 13374 / j. issn2095鄄鄄9389. 2019. 02. 011; http: / / journals. ustb. edu. cn 医用镍钛合金的制备与热压缩变形行为 王 臻1) , 徐效文1) 苣 , 王快社2) , 王 文2) 1) 中南大学生物医学工程系, 长沙 410083 2) 西安建筑科技大学冶金工程学院, 西安 710055 苣通信作者,E鄄mail:xuxiaowen@ csu. edu. cn 摘 要 采用真空感应熔炼法制备了医用 Ti鄄鄄50郾 7% Ni 合金(原子数分数),测试了铸态合金的成分、相变点、微观组织和硬 度,并采用 Gleeble鄄鄄3800 热模拟实验机在变形温度 750 ~ 950 益 、应变速率 0郾 001 ~ 1 s - 1 ,应变量为 0郾 5 的条件下对 Ni鄄鄄Ti 合金 进行高温压缩变形,分析其流动应力变化规律,建立了高温塑性变形本构关系和热加工图. 结果表明:当变形温度减小或应变 速率增大时,Ni鄄鄄Ti 合金的流动应力会随之增大. 应变速率为 1 s - 1时,合金的真应力鄄鄄真应变曲线呈现出锯齿状特征. 根据热 加工图,获得了 Ni鄄鄄Ti 合金的加工安全区和流变失稳区,进而确定其合理的热变形温度范围为 820 ~ 880 益 ,真应变速率低于 0郾 1 s - 1 . 从而为制定镍钛合金的锻造工艺参数提供理论和数据基础. 关键词 镍钛记忆合金; 热压缩变形; 应变曲线; 热加工图 分类号 TG174 收稿日期: 2018鄄鄄06鄄鄄07 基金项目: 甘肃省科技重大专项计划“镍产业链关键技术开发与产业化冶资助项目(17ZD2GC011) Preparation and hot compression deformation of biomedical Ni鄄鄄Ti alloy WANG Zhen 1) , XU Xiao鄄wen 1) 苣 , WANG Kuai鄄she 2) , WANG Wen 2) 1)Department of Biomedical Engineering, Central South University, Changsha 410083, China 2)School of Metallurgy Engineering, Xi爷an University of Architecture and Technology, Xi爷an 710055, China 苣Correspondent author, E鄄mail:xuxiaowen@ csu. edu. cn ABSTRACT A Ti鄄鄄50郾 7% Ni (atomic fraction) shape alloy was prepared by vacuum induction melting under dynamic argon atmos鄄 phere. By analyzing the composition, deformation temperature, microstructure, and hardness of the as鄄cast Ni鄄鄄 Ti shape alloy in this study, it was found that the properties of the as鄄cast Ni鄄鄄 Ti alloy met the medical standard. To analyze the variation law of the flow stress, the flow stress of the compression deformation for as鄄cast Ni鄄鄄 Ti alloy was studied by high鄄temperature compression with a Gleeble鄄鄄3800 simulated machine within a deformation temperature range of 750鄄鄄950 益 , strain rate range of 0郾 001鄄鄄1郾 0 s - 1 , and strain level of 0郾 5. To analyze the relationship between variables in the hot deformation process of as鄄cast Ni鄄鄄Ti alloy, a constitutive equation based on dynamic material model was established. To determine the reasonable range of hot working conditions for as鄄cast Ni鄄鄄Ti alloy deformation, hot processing maps under different hot deformation conditions were set up. The results show that when the deformation temperature decreases or strain rate increases, the flow stress of as鄄cast Ni鄄鄄 Ti alloy increases. This phenomenon shows that the main factors affecting the flow stress of as鄄cast Ni鄄鄄Ti alloy are deformation temperature and strain rate. When the strain rate is 1郾 0 s - 1 , the true stress鄄鄄true strain curves of as鄄cast Ni鄄鄄Ti alloy exhibits a zigzag feature. This is mainly attributed to the alternation between hard鄄 ening and softening during deformation. According to the hot processing maps under different hot deformation conditions, the processing zone and unstable hot deformation region of the as鄄cast Ni鄄鄄Ti alloy were obtained. Then, the best temperature range of hot deformation is determined as 820鄄鄄880 益 , and the true strain rate is less than 0郾 1 s - 1 . This study provides a theoretical and data basis for the de鄄 velopment of forging process parameters of Ni鄄鄄Ti alloy. KEY WORDS Ni鄄鄄Ti alloy; hot compression; strain curves; hot processing map