G.J. Yang , X.Z. Jin , D.B. Shan , B. Guo , M.T. Pérez-Prado , W.C. Xu
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引用次数: 0
Abstract
This work investigates room-temperature serrated flow and anomalous strength variations in forged 2195 Al–Li alloys as functions of forging temperature, focusing particularly on dense dynamic strain precipitation of intragranular icosahedral quasicrystalline phases T2. To achieve this, 2195 Al–Li alloys were forged at temperatures ranging from 180 to 460 °C, reaching a maximum cumulative strain of 2.4, thereby ensuring comparable microstructure and microtexture while varying dynamic precipitation behaviors. The study reveals that forging between 220 and 380 °C significantly promotes dynamic strain precipitation of intragranular, globular icosahedral quasicrystalline phases T2 (Al6CuLi3) due to the high-density, strain-induced crystal defects, which provide enhanced diffusion pathways and sufficient energy to surpass nucleation barriers. The size and average spacing of T2 particles increase with higher forging temperatures, extending the dislocation arrest duration at these precipitates. Consequently, alloys forged within 300–380 °C exhibit intensified serrated flow and severe strain localization during room-temperature tensile tests, resulting in substantially lower tensile elongation compared to alloys forged above 420 °C. The tensile strength initially decreases and then sharply rises with forging temperatures from 300 to 460 °C, reaching a minimum at approximately 380 °C, coinciding with the precipitation or absence of T2 phases. This work paves the way for the designation of high-performance 2195 Al–Li alloys by hot deformation.
期刊介绍:
The Journal of Materials Research and Technology is a publication of ABM - Brazilian Metallurgical, Materials and Mining Association - and publishes four issues per year also with a free version online (www.jmrt.com.br). The journal provides an international medium for the publication of theoretical and experimental studies related to Metallurgy, Materials and Minerals research and technology. Appropriate submissions to the Journal of Materials Research and Technology should include scientific and/or engineering factors which affect processes and products in the Metallurgy, Materials and Mining areas.