Optimizing Mechanical Properties of AlCoCrFeNiTi_x High-Entropy Alloys by Tailoring Microstructures

Yinfeng WANG¹，Shengguo MA²，Xiaohua CHEN²，Juyan SHI¹，Yong ZHANG²，Junwei QIAO^1,3

1. College of Materials Science and Engineering, Taiyuan University of Technology2. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing3. Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology

摘 要：The effects of Ti addtions and the heat treatment on the mechanical properties of AlCoCrFeNiTix （x = 0, 0.2, 0.3, 0.4 and 0.5） high-entropy alloys （HEAs） were studied. The results show that the dendrite phase with a body-centered-cubic （bcc） structure transforms into the interdendrite phase with a new bcc structure. With the increase of the Ti contents and heat-treatment temperature, the average hardness and yield strengths are greatly improved, and the highest hardness and yielding strength are 583 HV and 2.07 GPa, respectively in the investigated HEA system. The as-cast and annealed HEAs exhibit excellent mechanical properties, combining with high yielding strength and plasticity. The solid solution strengthening mechanism of Ti additions is responsible for the strengthening effect of AlCoCrFeNiTix HEAs.

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