快速凝固Al－TiC自生复合材料的显微组织和力学性能

MICROSTRUCTURE AND PROPERTIES OF A RAPIDLY SOLIDIFIED INSITU Al-TiC COMPOSITE

将常规熔铸工艺与快速凝固技术相结合，成功地制备出Ａｌ－ＴｉＣ自生复合材料．常规熔铸Ａｌ－ＴｉＣ自生复合材料中ＴｉＣ的体积分数为１４．５％，颗粒尺寸为０．２－１．０μｍ，一般呈聚集态分布；与类似工艺条件下的人工复合材料相比，业已表现出较好的综合力学性能．快凝及热挤成型以后，ＴｉＣ的体积分数约为１３．５％，颗粒尺寸减至４０－８０ｎｍ，并弥散分布于晶粒尺寸为０．３０－０．８０μｍ的α－Ａｌ基体上，室温拉伸强度增加了约１００ＭＰａ，表现出良好的高温力学性能．

Combining the advantages of ingot metallurgy,rapid solidification technology and in situ processed composites,a kind of innovative in situ Al-TiC composite has been successfully made with a series of research on its microstructure and properties.The ingot metallurgy microstructures exhibited that the accumulated TiC particulate phase with a volume fraction of 14.5% and sizes of 0.2-1.0μm segregated generally at the α-Al grain boundaries.After rapid solidification and thermal extrussion,the microstructures comprise uniform fine-scale dispersions of TiC phase particles(the volume fraction slightly reduced as 13.5%) with sizes of 40-80 nm in a supersaturated α-Al matrix of 0.30-0.80 μm grain sizes.The rapidly solidified in situ Al-TiC composite exhibited high Young's modulus and substantial improvements in room and elevated temperature tensile properties.