The research studied two different kinds of n-SiCp/2024 aluminum matrix composite ingots,with hot backward extrusion and T6 heat treatment,which were processed by low frequency electromagnetic casting (LFEC) and conventional semi-continuous casting (DC) respectively.The OM,TEM,and tensile test were adopted to study the microstructure and mechanical properties variations of the two different kinds of n-SiCp/2024 aluminum matrix composites.The research proved that there were segregations on part of the DC processed n-SiCp/2024 aluminum matrix composite ingots' surface.Most of them located near the grain boundaries in clumps,while only very little of them located within the grain The LFEC processed n-SiCp/2024 aluminum matrix composite,however,had practically no n-SiCp in clumps and had a clear grain boundary,a uniform microstructure,and an obvious grain refining effect.LFEC process could refine the grain size of n-SiCp/2024 aluminum matrix composite ingots effectively,and its electromagnetic stirring relieved clumps of n-SiCp grain significantly.Compared with the conventional DC process,the LFEC process could improve both the strength and the ductility.%分别采用低频电磁铸造(LFEC)与传统半连续铸造(DC)制备n-SiCp/2024复合材料铸锭,并对铸锭进行挤压以及T6热处理.通过金相组织观察(OM) 、TEM、室温力学性能测试等手段,分别研究了低频电磁铸造与传统半连续铸造工艺对n-SiCp/2024复合材料的微观组织、力学性能的影响情况.实验结果表明:DC制备的n-SiCp/2024复合材料铸锭表面局部存在偏析瘤,大多数n-SiCp团聚在晶界处,只有少数聚集在晶粒内部;LFEC制备的n-SiCp/2024复合材料铸锭组织晶界清晰,n-SiCp团聚现象基本消失,组织均匀,晶粒细化效果明显.LFEC制备工艺可以有效细化n-SiCp/2024复合材料铸锭的晶粒尺寸,其电磁搅拌作用对消除n-SiCp颗粒的团聚现象有显著作用;与DC工艺相比,LFEC可同时提高复合材料的强度与延伸率.
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