Surface modification of plasma nitriding on Al_xCoCrFeNi high-entropy alloys

Jinxiong Hou¹，Wenwen Song²，Liwei Lan¹，Junwei Qiao^3,4

1. College of Materials Science and Engineering, Taiyuan University of Technology2. Steel Institute, RWTH Aachen University3. College of Materials Science and Engineering,Taiyuan University of Technology4. Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education,Taiyuan University of Technology

摘 要：Plasma nitriding is successfully employed in treating Al_xCoCrFeNi high-entropy alloys（HEAs） with finelydivided Al content（i.e.,x values in molar ratio,x=0.1-0.8） to develop wear-resistant structural materials.Nitridation greatly removes the Al from the matrix that completely deplete the Ni-Al enriched phase,forming nanoscaled nitrides（AIN and CrN） precipitations near the surface.Nitriding promotes the hardness of present alloys with values widely ranging from 276 HV to 722 HV.Interestingly,the higher content the Al,the smaller thickness the nitrides layer,but the higher hardness due to the increased amount of hard nitrides phases and volume fraction of BCC phase.Significantly,plasma nitriding considerably improves the wear re sistance of Al_xCoCrFeNi HEAs by 4-18 times.

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