摘要
Enhanced oxidation resistance is a primary demand for the application of refractory high-entropy alloys(RHEAs)at elevated temperatures.In this study,Al was added to a Ti_(2)VZrNb RHEA to partially substitute Nb to improve its oxidation resistance and mechanical properties.The alloy was found to have an increased oxidation resistance by forming a continuous Al_(2)O_(3)+ZrO_(2)oxide protective surface.At the same time,the room-temperature yield strength was also increased by 66%to 1273 MPa via solid solution strengthening.The low atomic mass of Al also helped to reduce the density of the alloy by 8.2%to 5.44 g cm^(−3).This resulted in a high specific yield strength of 234 MPa cm3 g^(−1) for the alloy.Meanwhile,the Ti_(2)VZrNb_(0.5)-Al_(0.5)alloy also exhibited a high compressive plasticity of>50%.These values are among the best reported so far for RHEAs.
提高抗氧化性能是难熔高熵合金高温应用的首要要求.本研究中,我们将Al代替50%Nb添加到Ti_(2)VZrNb难熔高熵合金中,以提高其抗氧化性能与力学性能.结果表明,相比于Ti_(2)VZrNb合金,Ti_(2)VZrNb_(0.5)-Al_(0.5)合金的抗氧化性得到了显著提升,这是由于在合金表面形成了连续的Al_(2)O_(3)+ZrO_(2)氧化层保护膜.同时,Ti_(2)VZrNb_(0.5)-Al_(0.5)合金室温屈服强度高达1273 MPa,相比于Ti_(2)VZrNb合金强度提升66%.结构表征说明,Ti_(2)VZrNb_(0.5)-Al_(0.5)合金强度提升得益于其较大的固溶强化效果.较轻元素Al的添加使得该合金具有较低的密度(5.44 g cm^(−3)),相比于T i_(2)V Z r N b合金密度降低8.2%,这使得该合金的比强度高达234 MPa cm3 g^(−1).同时,Ti_(2)VZrNb_(0.5)-Al_(0.5)合金也具有较高的压缩塑性(>50%).综合这些结果,该合金是迄今为止所报道的性能最好的难熔高熵合金.
作者
Zibing An
Shengcheng Mao
Tao Yang
Yinong Liu
Yanhui Chen
Xiaomeng Yang
Shanshan Liu
Xin Wang
Qingsong Deng
Ze Zhang
Xiaodong Han
安子冰;毛圣成;杨涛;刘亦农;陈艳辉;杨晓萌;刘珊珊;汪鑫;邓青松;张泽;韩晓东(Beijing Key Lab of Microstructure and Property of Advanced Materials,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China;Department of Materials Science and Engineering,College of Science and Engineering,City University of Hong Kong,Hong Kong,China;Department of Mechanical Engineering,The University of Western Australia,Perth,WA 6009,Australia;State Key Laboratory of Silicon Materials,Department of Materials Science and Engineering,Zhejiang University,Hangzhou 310058,China)
基金
supported by the National Key R&D Program of China(2021YFA1200201)
the National Natural Science Foundation of China(52071003,91860202,and 11604006)
Beijing Nova Program(Z211100002121170)
Beijing Municipal Education Commission Project(PXM2020_014204_000021 and PXM2019_014204_500032)
Beijing Outstanding Young Scientists Projects(BJJWZYJH01201910005018)
Beijing Natural Science Foundation(Z180014)
“111”project(DB18015)。
