A combination strategy of strengthening for enhancing impact-resistance property in high entropy alloys

• Published in: Materials characterization Vol. 215; p. 114150
• Main Authors: Liu, Kun, Sun, Qing-ya, Li, Xin, Wang, Kang, Xiang, Yu-hang, Yang, Xiao-ning, Malomo, Babafemi, Yang, Liang
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.09.2024
• Subjects: High entropy alloy; Impact-resistance property; L12 structure precipitate; Laves phase; Impact-resistance property; High entropy alloy; L12 structure precipitate; Laves phase
• ISSN: 1044-5803
• DOI: 10.1016/j.matchar.2024.114150

Developing new high-entropy alloy system has been a subject of significant research interest in recent years. However, it is a challenge to enhance the impact-resistance property in existing high-entropy alloys. Here we proposed a combination strategy of strengthening via second phase and grain refining to build a network microstructure in Co2Ni2CrVTa0.3 high entropy alloys that could significantly enhance the ballistic limit velocity from 407.8 m/s to 435.4 m/s. Especially, under a high impact velocity of 750 m/s, the energy absorption of the alloy was evidently larger than that of the Ta-free alloy. The microstructure of Co2Ni2CrVTax alloys could be sensitively tuned via Ta addition because of the Ta-induced multi-scale microstructure involving the micro-scale Laves phase and nano-scale L12 structure precipitates. This should be the structural mechanism of the enhanced impact-resistance property, and will shed light on the development of alloys with excellent impact-resistance property. •A combination strategy of strengthening was proposed.•Co2Ni2CrVTax HEAs were developed.•A network microstructure with multi-scale second phase particles was built.•Co2Ni2CrVTa0.3 HEA had 435.4 m/s ballistic limit velocity.