Fabrication of ultrafine-grained Ti-15Zr-xCu alloys through martensite decompositions under thermomechanical coupling conditions  

作　　者：Wenwei Gao Hai Wang Konrad Koenigsmann Shuyuan Zhang Ling Ren Ke Yang 

机构地区：[1]Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China [3]University of Chicago,Chicago,IL 60637,USA

出　　处：《Journal of Materials Science & Technology》2022年第32期19-28,共10页材料科学技术（英文版）

基　　金：the National Key Research and Development Program of China(No.2018YFC1106601);the Doctoral Scientific Research Foundation of Liaoning Province(No.2020BS002)。

摘　　要：Grain refinement is a well-recognized method to simultaneously increase the strength and ductility of metallic materials.Fabrication of ultrafine-grained metals in bulk using a simple low-cost approach is a long-term goal for material scientists.In this work,based on the chemical composition of a biomedical Ti-15Zr alloy,a series of novel Ti-15Zr-xCu(x=0,3,5,7 wt.%)alloys were designed and fabricated.The alloys were quenched in the singleβphase region to obtain a martensitic microstructure and deformed in the temperature range of 710–750℃to obtain an ultrafine-grained microstructure through martensite decomposition under thermomechanical coupling conditions.Experimental results showed that Cu alloying could increase the dynamic recrystallization(DRX)nucleation rate due to its role in both refining martensitic lath width and increasing dislocation density.Cu alloying could also suppress grain growth due to the precipitated Ti_(2)Cu particles exerting pinning forces on the grain boundaries.The optimal Cu content in the Ti-15Zr-xCu alloy was determined to be 5 wt.%.After being subjected to a compression leading to a 70%height reduction at 730℃and 1 s^(–1),the grain size of the Ti-15Zr-5Cu alloy was only 180±70 nm.The tensile strength of the as-prepared alloy reached 975±10 MPa,which was 45%higher than that of the conventional Ti-15Zr alloy(673±16 MPa).This increase in strength was achieved without any reduction in ductility.The comprehensive mechanical properties of the ultrafinegrained Ti-15Zr-5Cu alloy are better than that of the Roxolid Ti–Zr alloy currently used for dental implants.

关 键 词：Titanium alloy Dynamic recrystallization Hot deformation Nucleation 

分 类 号：TG146.23[一般工业技术—材料科学与工程]