摘要
采用真空热压烧结工艺制备了CoCrCuFeMn和CoCrCuFeMnNi两种高熵合金,对其微观组织、力学性能和在质量分数为3.5%的NaCl溶液中的腐蚀性能进行了研究。结果表明,两种合金均由富Cr-Co-Mn-Fe的FCC1主相、富Cu-Mn的FCC2次要相和少量富Cr-Fe的σ相组成。CoCrCuFeMnNi合金的屈服强度、断裂强度和硬度(HV)分别为(1121±14)MPa、(1936±17)MPa和400±5,与CoCrCuFeMn合金相比,分别增加了18.6%、9.9%和15.3%,断裂应变为(25.3±1.0)%,较CoCrCuFeMn合金下降了9.3%。两种合金的断裂形式主要为准解理断裂。在3.5%的NaCl溶液中,CoCrCuFeMnNi合金的腐蚀电位、腐蚀电流密度和平均腐蚀速率分别为-74.1mV、5.48×10^(-5) A/cm^(2)和0.059mm/a,表现出较好的耐腐蚀性能,这主要归因于Ni的加入使合金中富Cu的FCC2相含量降低,各元素分布趋于均匀,偏析现象减弱,降低了原电池腐蚀程度,从而改善了合金的耐蚀性能。
CoCrCuFeMn and CoCrCuFeMnNi high entropy alloys were prepared by vacuum hot pressing sintering process,and the microstructure,mechanical properties and corrosion resistance of alloys in 3.5%NaCl solution were investigated.The results indicate that both alloys are composed of(Cr,Co,Mn,Fe)-rich FCC1 primary phase,(Cu,Mn)-rich FCC2 secondary phase,and a small amount of(Cr,Fe)-richσphase.The yield strength,fracture strength and microhardness of CoCrCuFeMnNi alloy are(1121±14)MPa,(1936±17)MPa and(400±5)HV,which are increased by 18.6%,9.9%and 15.3%,respectively,while the fracture strain is(25.3±1.0)%,which is decreased by 9.3%compared with CoCrCuFeMn alloy.The fracture mode of alloys is dominated by quasi cleavage fracture.In 3.5%NaCl solution,the corrosion potential(E_(corr)),corrosion current density(J_(corr))and average corrosion rate(V_(corr))of CoCrCuFeMnNi alloy are-74.1 mV,5.48×10^(-5)A/cm^(2),and 0.059 mm/a,respectively,showing desirable corrosion resistance,which is mainly attributed to the fact that the addition of Ni reduces the content of Cu-rich FCC2 phase in the alloy,and the distribution of elements tends to be uniform as well as weakening the segregation phenomenon,so the corrosion degree of galvanic cell is reduced,thus improving the corrosion resistance of the alloy.
作者
邵亚云
郭富强
Shao Yayun;Guo Fuqiang(Department of Prelimary Teaching,Zhengzhou University of Industrial Technology)
出处
《特种铸造及有色合金》
CAS
北大核心
2023年第7期888-894,共7页
Special Casting & Nonferrous Alloys
基金
河南省本科高等学校“十四五”规划教材建设项目(教高[2020]469号)。
关键词
高熵合金
真空热压烧结
微观组织
力学性能
耐蚀性能
High-entropy Alloy
Hot Pressing Sintering
Microstructure
Mechanical Properties
Corrosion Resist-ance
