(合肥工業(yè)大學 材料科學與工程學院，合肥 230009)
摘 要: 以純鋁粉末多孔燒結材料為研究對象，在200 ℃下采用粉末包套−等通道轉角擠壓工藝制備了完全致密的塊體超細晶材料，研究在擠壓過程中3種路徑(A、BC、C)對其組織和性能的影響。結果表明：在3種路徑擠壓下均實現(xiàn)了材料的晶粒細化與致密，其中路徑BC和路徑A的細化效果優(yōu)于路徑C的；以細化效果最佳的路徑BC為例，初始平均粒徑為46.8 µm，相對密度為0.88的粗大等軸晶組織經(jīng)過4道次擠壓后得到平均粒徑為1.5 µm完全致密的超細晶組織，且屈服強度比初始時提高了兩倍左右；3種路徑下顯微硬度與擠壓道次的關系基本一致，即一次擠壓后硬度比初始值提高了75%，之后隨著擠壓道次的增加，硬度增加趨于緩慢。
關鍵字: 粉末燒結材料；組織；性能；包套−等通道轉角擠壓
（School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China）
Abstract: Pure aluminium sintered material was successfully consolidated into fully dense bulk material by powder in tubes-equal channel angular pressing at 200 ℃. During the pressing, the effects of three routes (A, BC, C) on the structure and properties were studied. The results show that the materials are refined and compacted after pressing through three kinds of routes. The refining effect of routes BC and A are better than that of route C. Using route BC as example, the initial coarse equiax-grained microstructure with relative density of 0.88 and mean grain size of 46.8 µm becomes fully dense ultra-fine grained microstructure with mean grain size about 1.5 µm after four pressing passes. The yield strength is two times higher than that of sample before ECAP processed. The relationship between the microhardness and pressing passes under three routes is the same, that is to say the microhardness increases 75% after one pressing, while increases slightly where after.
Key words: powder sintered material; microstructure; properties; tubes-equal channel angular pressing
