摘要
随着经济的发展和人口老龄化的加剧,医用金属材料在创伤外科、整形手术和口腔医疗中的需求量越来越大。其中钛及钛合金具有优异的耐腐蚀性能和良好的生物相容性,因此被广泛应用。钛合金中含有对人体有害的合金元素,会使人体出现病症,因此不含合金元素的工业纯钛在生物医学材料领域越来越受到重视。近几十年来,国内外学者应用等径通道挤压(ECAP)技术成功制备出超细晶工业纯钛。但是ECAP技术制备超细晶材料存在细化和强化极限,而且ECAP道次数较多,工序复杂,生产效率低,对工件的尺寸和形状要求很高,因此限制了超细晶工业纯钛的应用。为了使工业纯钛的强度满足使用要求,并且开发出易于实际运用的加工技术,将ECAP与传统塑性加工相结合(复合变形技术)的研究和应用越来越多。工业纯钛先经多道次ECAP变形细化晶粒,再经传统塑性加工提高位错密度,其强度可增加到1000 MPa左右,并且保持良好的塑性。后变形使ECAP变形后的等轴晶粒被拉长,且分布不均匀,材料的力学性能表现出强烈的各向异性。复合变形可以运用较少道次的ECAP,缩短了加工周期。此外,通过后变形可以将材料加工成所需的成品形状,更易于生产和应用。复合变形后的超细晶工业纯钛进行低温退火可以提高材料的塑性,得到更优的综合力学性能。本文综述了复合变形制备超细晶工业纯钛的研究进展,分别对不同复合变形后工业纯钛的显微组织、力学性能、热稳定性和织构演变进行了介绍。对复合变形制备超细晶工业纯钛过程中存在的问题和今后的研究方向进行了总结和展望,以期为开发高效率易加工的复合变形技术提供参考。
With the development of economy and the aging of population,the demand for metal materials in trauma surgery,plastic surgery and dental medicine is increasing.Titanium and its alloys have been widely used in biomedical engineering due to their excellent corrosion resistance and good biocompatibility.The slow dissolution and accumulation of alloying elements of titanium alloys in human body can cause illness,so commercially pure titanium without alloying elements has attracted much attention in the field of biomedical materials.In recent decades,ultrafine grained(UFG)commercially pure titanium has been successfully prepared by equal channel angular pressing(ECAP).However,there are grain refinement and strengthening limits in the UFG materials prepared by ECAP.It is limited the application of UFG commercially pure titanium due to the low production efficiency of multi-passes ECAP,and the high requirement on the size and shape of the workpiece.In order to meet the high strength requirements of commercially pure titanium and develop processing technology which is easy to be applied in practice,ECAP combined with traditional plastic processing(complex deformation technology)has been extensively studied and applied.The strength of commercially pure titanium increases to about 1000 MPa and the plasticity remains good after complex deformation(multi-passes of ECAP and followed by conventional plastic processing),which is due to grain refinement and the increase in the dislocation density.After post-deformation,the equiaxed grains after ECAP are elongated and unevenly distributed,which leads to the strong anisotropy of mechanical properties.The complex deformation can use less passes of ECAP,shorten the processing cycle,and transform the material into the desired finished shape,making it easier to use in production and application.The ductility of UFG commercially pure titanium after complex deformation can be improved by low-temperature annealing.In this paper,the research progresson the preparation of UFG commercially pure titanium by complex deformation is reviewed.It focuses on the microstructure,mechanical properties,thermal stability and texture evolution of commercially pure titanium after different complex deformation.The research status and existing problems in preparation of ultrafine grained commercially pure titanium by complex deformation technology and the further research direction are pointed out.It can provide reference for the development of high-efficiency and easy-to-process complex defor-mation technology.
作者
刘晓燕
张琪
高飞龙
杨西荣
罗雷
柳奎君
LIU Xiaoyan;ZHANG Qi;GAO Feilong;YANG Xirong;LUO Lei;LIU Kuijun(School of Metallurgical Engineering,Xi’an University of Architecture&Technology,Xi’an 710055,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2020年第19期19111-19116,共6页
Materials Reports
基金
国家自然科学基金(51474170)
陕西省医用金属材料重点实验室开放基金(SXBMM-201903)。
关键词
工业纯钛
复合变形
显微组织
力学性能
织构演变
热稳定性
commercially pure titanium
complex deformation
microstructure
mechanical properties
texture evolution
thermal stability
