Bimodal grain structures and tensile properties of a biomedical Co-20Cr-15W-10Ni alloy with different pre-strains

作     者：Cheng-Lin Li Seong-Woo Choi Jeong Mok Oh Jae-Keun Hong Jong-Taek Yeom Joo-Hee Kang Qing-Song Mei Chan Hee Park Cheng-Lin Li;Seong-Woo Choi;Jeong Mok Oh;Jae-Keun Hong;Jong-Taek Yeom;Joo-Hee Kang;Qing-Song Mei;Chan Hee Park

作者机构：Department of Materials EngineeringSchool of Power and Mechanical EngineeringWuhan UniversityWuhan 430072China Advanced Metals Division.Korea Institute of Materials ScienceChangwon 51508Republic of Korea Materials Testing&Reliability DivisionKorea Institute of Materials ScienceChangwon 51508Republic of Korea 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2021年第40卷第1期

页      面：20-30页

核心收录：

学科分类：08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：financially supported by the Korea Institute of Materials Science(No.PNK7140) the National Key R&D Project of Ministry of Science and Technology of China(No.2020YFC1107200) 

主　　题：Biomaterials Bimodal grain structure Deformation heterogeneity Pinning High strength/ductility 

摘      要：The influence of pre-strain on the formation of bimodal grain structures and tensile properties of a Co-20 Cr-15 W-10 Ni alloy was *** bimodal grain structures consist of fine grains(FGs;2-3μm in diameter)and coarse grains(CGs;8-16μm in diameter),which can be manipulated by changing the pre-strain(ε=0.3-0.7)and annealing temperatures(1000-1100℃).High pre-strain applied in the samples can intensify the plasticity heterogeneity through increasing the total dislocation density and the local volumes of high-density *** can essentially result in finer FGs,a higher FG volume fraction,and overall grain refinement in the samples after ***-temperature essentially increases both the size and volume fraction of CGs,leading to an increase in the average grain *** tensile test suggests that the bimodal grain structured samples exhibited both high strength and ductility,yield strengths of621-877 MPa and ultimate tensile strengths of1187-1367 MPa with uniform elongations of 55.0%-71.4%.The superior strength-ductility combination of the samples arises from the specific deformation mechanisms of the bimodal grain *** tensile properties strongly depend on the size ratio and volume fraction of FGs/CGs in addition to the average grain size in the bimodal grain *** grain structures can be modified via changing the pre-strain and annealing temperature.