Effect of α-Platelet Thickness on the Mechanical Properties of Ti-6Al-4V Alloy with Lamellar Microstructure

[摘要] In this paper, lamellar microstructures with average α-platelet thicknesses ranging from 0.55 μm to 1.98 μm were obtained in Ti-6Al-4V (Ti64) alloy by solution-treated above β-transus temperature and followed cooling through different methods. Then effects of the average thickness of plate-like α phase on the mechanical properties of this alloy were investigated. The results show that the yield stress and/or the flow stress of Ti64 decrease with increased average α-platelet thickness during compression under various strain-rate and temperature conditions. Conversely, the ductility increases with increased average α-platelet thickness. The greater plate thickness facilitates slip and avoids severe pile-up of dislocations in α phase, resulting in the augmentation of the fracture strain as well as decrease of the strength of Ti64. Finally, the variation of yield stress with average α-platelet thickness satisfies Hall-Petch relationship at both quasi-static and dynamic loading strain-rates.

[发布机构] School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing; 102206, China^1;No. 52 Institute of China Ordnance Industries, Yantai, Shandong; 264003, China^2;School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing; 100083, China^3

[效力级别] 机械制造 [学科分类] 材料科学（综合）

[关键词] Beta transus;Fracture strain;Hall Petch relationship;Lamellar microstructure;Plate thickness;Quasi-static;Temperature conditions;Ti-6Al-4V alloy