Effect of Si on Microstructure and Mechanical Properties of FeCrNi Medium Entropy Alloys

Fang Ding; Yuankui Cao; Ao Fu; Jian Wang; Weidong Zhang; Jingwen Qiu; Bin Liu

doi:10.3390/ma16072697

Effect of Si on Microstructure and Mechanical Properties of FeCrNi Medium Entropy Alloys

Materials (Basel). 2023 Mar 28;16(7):2697. doi: 10.3390/ma16072697.

Authors

Fang Ding¹, Yuankui Cao¹, Ao Fu¹, Jian Wang¹, Weidong Zhang², Jingwen Qiu³, Bin Liu¹

Affiliations

¹ State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China.
² College of Materials Science and Engineering, Hunan University, Changsha 410082, China.
³ Hunan Provincial Key Laboratory of High Efficiency and Precision Machining of Difficult-to-Cut Material, Hunan University of Science and Technology, Xiangtan 411201, China.

Abstract

FeCrNi medium entropy alloy (MEA) has been widely regarded for its excellent mechanical properties and corrosion resistance. However, insufficient strength limits its industrial application. Intermetallic particle dispersion strengthening is considered to be an effective method to improve strength, which is expected to solve this problem. In this work, microstructural evolution and mechanical behavior of FeCrNi MEA with different Si content were investigated. We found that the precipitation of fine σ particles can be formed in situ by thermomechanical treatment of Si doping FeCrNi MEAs. The FeCrNiSi_0.15 MEA exhibits a good combination of strength and ductility, with yield strength and tensile elongation of 1050 MPa and 7.84%, respectively. The yield strength is almost five times that of the as-cast FeCrNi MEA. The strength enhancement is mainly attributed to the grain-boundary strengthening and precipitation strengthening caused by fine σ particles.

Keywords: mechanical property; medium entropy alloy; microstructure; strengthening mechanism; thermomechanical treatment.

Abstract

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