Potential of multi-pass ECAP on improving the mechanical properties of a high-calcium-content Mg-Al-Ca-Mn alloy

• 作者: Aibin Ma Ce Wang Feng Xue He Huang Huan Liu Jiapeng Sun Jing Bai Jinghua Jiang
• 来源期刊: 镁合金学报(英文)
• 学科: 工学
• 关键词: Mg-Al-Ca-Mn alloy Equal channel angular pressing Dynamic recrystallization PRECIPITATES Mechanical property
• 年，卷（期）: mhjxbyw_2019,（4）
• 页码范围: 617-627
• 页数: 11页
• 分类号: TG1

摘要

In this study,the multi-pass equal channel angular pressing(ECAP)was employed on a high-calcium-content Mg-Al-Ca-Mn alloy to tailor its microstructure and mechanical properties.The obtained results showed that the network-shaped Mg2Ca and(Mg,Al)2Ca eutectic compounds in as-cast alloy were gradually crushed into ultra-fine particles after ECAP,which exhibited a bimodal particle size distribution and most aggregated at original grain boundaries.Dynamic recrystallization(DRX)of α-Mg occurred during hot deformation via a particle stimulated mechanism,and the almost complete DRX with an average grain size around 1.5μm was obtained after 12p-ECAP.Moreover,abundant nano-sized acicular and spherical precipitates were dynamically precipitated withinα-Mg grains during ECAP.Tensile test results indicated that the maximum strength and ductility were acquired for 12p-ECAP alloy with ultimate tensile strength of 372 MPa and fracture elongation of 8%.The enhanced strength of the alloy could be ascribed to fine DRX grains,ultra-fine Ca-containing particles and dynamically precipitated nano-precipitates,while the improved ductility was mainly due to the refined and homogeneous microstructure,and weak texture with high average Schmid factors.