Microstructures and mechanical properties of extruded 2024 aluminum alloy reinforced by FeNiCrCoAl_3 particles

FeNiCrCoAl_3颗粒增强2024铝合基复合材料的显微组织和力学性能(英文)

Different proportions of commercial 2024 aluminum alloy powder and FeNiCrCoA13 high entropy alloy （HEA） powder were ball-milled （BM） for different time. The powder was consolidated by hot extrusion method. The microstructures of the milled powder and bulk alloy were examined by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Mechanical properties of the extruded alloy were examined by mechanical testing machine. The results show that after BM, the particle size and microstructures of the mixed alloy powder change obviously. After 48 h BM, the average size of mixed powder is about 30 nm, and then after hot extrusion, the average size of grains reaches about 70 rim. The compressive strength of the extruded alloy reaches 710 MPa under certain conditions of milling time and composition. As a result of the identification of the nano-/micro-strueture-property relationship of the samples, such high strength is attributed mainly to the nanocrystalline grains of a（Al） and nanoscaled FeNiCrCoAl3 particles, and the fine secondary phase of Al2Cu and Fe-rich phases.

将不同比例的2024商业铝粉和由气雾化法制得的FeNiCrCoAl3高熵合金粉球磨不同时间,然后,将混合粉末通过热挤出方法成型。通过XRD、SEM和TEM方法研究球磨粉和烧结后合金的显微组织,并通过应力测试机测试挤出样品的力学性能。结果表明:球磨后,粉末的晶粒尺寸减小,显微组织发生变化。混合粉末经过48h球磨后,颗粒平均直径约为30 nm;粉末在热挤出后,晶粒尺寸约为70 nm。在适当条件下,热挤出合金的压缩强度达到710 MPa。通过对样品组织和性能关系的分析发现:强度的增加主要归因于纳米α(Al)和FeNiCrCoAl3颗粒以及析出的超细二次相Al6Fe相和富Fe相。