具有bcc结构的β型钛或锆系合金的低模量机制  

Mechanism for Low Modulusin β-Type Titanium or Zirconium Alloys with Body-Centered Cubic Structure

作　　者：侯艳嫔 吴亭慧 郭顺[1] 刘海霞[1] 程晓农[1] Hou Yanpin;Wu Tinghui;Guo Shun;Liu Haixia;Cheng Xiaonong(School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《稀有金属》2024年第5期745-752,共8页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51771082);江苏省六大人才高峰项目(2019-XCL-113);镇江市科技计划项目(GY2020001);江苏大学农业装备学部项目(NZXB20200101)资助。

摘　　要：低弹性模量的三元β型钛或锆系合金中的体心立方(bcc)结构多处于不稳定状态,因此难以通过制备单晶的方式来直接测定单晶弹性常数。利用原位同步辐射高能X射线衍射(SXRD)技术和Eshelby-Kroner-Kneer弹塑性自洽模型,获取了具有bcc结构的三元Ti-33Nb-4Sn,Ti-35Nb-4Sn,Zr-12Nb-4Sn和Zr-4Mo-4Sn多晶合金的单晶弹性常数,成功解决了此类合金难以通过制备单晶来直接获得单晶弹性常数的技术瓶颈,揭示了具有bcc结构的多晶β型钛或锆系合金的低模量机制。结果表明,与二元β型TiV,TiCr和TiNb单晶合金相比,经冷轧退火处理的Ti-33Nb-4Sn和Ti-35Nb-4Sn合金和固溶处理的Zr-12Nb-4Sn和Zr-4Mo-4Sn合金具有较低的■剪切模量C′和超低的{001}<100>剪切模量C_(44)。基于Hill近似理论进一步分析可知,三元β型Ti-33Nb-4Sn,Ti-35Nb-4Sn,Zr-12Nb-4Sn和Zr-4Mo-4Sn合金较低的剪切模量C′以及超低的剪切模量C_(44),是此类合金呈现较低杨氏模量E_(H)的原因。通过合理的成分设计及热机械处理降低合金的剪切模量C′和C_(44),可望获得与人骨模量相近的超低模量钛或锆合金。Recently,β-type titanium and zirconium alloys with body-centered cubic (bcc) structure for biomedical applications,have been attracted considerable attention due to their relatively low moduli,which are essential to avoid the bone degradation and the absorption originating from the difference in the elastic modulus between human bone and implant.Nonetheless,the mechanism for low elastic modulus,especially in the ternary and quaternary β-type titanium and zirconium alloys (such as Ti-Nb-Sn,Zr-Nb-Mo,ZrSi-Nb,Zr-Mo-Sn,Ti-Nb-Ta-Zr and Ti-Nb-Zr-Sn alloys),has not yet been elucidated in detail,although a deeper under standing on this issue could pave the way for further decreasing the elastic modulus of biomedical β-type alloys.It is well known that the elastic modulus of β-type alloys with bcc structure is closely associated with their single-crystal elastic constants (SECs).In general,these elastic parameters (i.e.,C_(11),C_(12) and C_(44)) can be obtained directly in β-type single crystal alloys by conventional resonant ultrasound spectroscopy.However,in most ternary β-type titanium or zirconium alloys with low elastic modulus,it is quite hard to fabricate the corresponding single crystals for obtaining their SECs directly because of the low bcc-structural (β phase) stability.In this study,four types of representative ternary β-type polycrystalline titanium and zirconium alloys with low elastic modulus (including the cold rolled plus annealed Ti-33Nb-4Sn and Ti-35Nb-4Sn alloys,together with the solution treated Zr-12Nb-4Sn and Zr-4Mo-4Sn alloys) had been selected,and the in situ synchrotron X-ray diffraction (SXRD) technique was carried out to obtain the experimental values of diffraction elastic constants (DECs) for their corresponding{110}_β,{200}_β,{211}_β and{310}_β crystallographic planes.Meanwhile,through running repeatedly Eshelby-Kroner-Kneer elastoplastic self-consistent model with different hypothetical SECs and evaluating the minimum weighted sum of squared residuals between the calculated DECs

关 键 词：β型钛或锆系合金 低弹性模量 同步辐射X射线衍射(SXRD) 弹性常数 

分 类 号：TG146.2[一般工业技术—材料科学与工程]