pISSN : 1598-706X / eISSN : 2288-8381
한국주조공학회지 (22권1호 42-48)
Characteristic Evaluation of Iron Aluminide-Cu and Ni-P Coated SiCp Preform Fabricated by Reactive Sintering Process
반응소결법으로 제조한 Iron Aluminide-Cu 및 Ni-P 피복 SiCp 예비성형체의 특성평가
Sung-Joon Kim, Jae-Sang Cha, Dap-Chun Choi
Chonnam National University
Effects of coating treatment of metallic Cu, Ni-P film on Siq, for SiCP/iron aluminide composites were studied. Porous hybrid preforms were fabricated by reactive sintering after mixing the coated Si(.}, Fe and Al powders. Then the final composites were manufactured by squeeze casting after pouring AC4C Al alloy melts in preforms. The change of reactive temperature, density, microstructure of the preforrns and microstructure of the composites were investigated. The exprimental results were summa- rized as follows. The thickness of Cu and Ni-P metallic layer formed on SiC;, by electroless plating method were about 0.5 um and coated uniformly. There was no remakable change in the ignition temperature with variation ofthe mixing ratio of Fe and Al powder while in the ease ofcoated SiCP it was lower about 20°C than in the non-coated SiC,, The maximum reaction temperature increased with increasing Al contents, but decreased with increasing SiC§, contents. Expansion ratio ofpreform after reactive sin- tering increased with amount of Cu coated SiCp In the case of Fe-7oat.%Al, the expansion ratio was about 7% up to 8wt.% of SiCP addition but further addition of SiCP increased the ratio significantly. And in the case of Fe-50 and 6oat.%Al, it was about 20% up to l6wt.% of SiC,, addition and about 28% in 24wt.% of SiCP addition. The microstructures of compounds showed that the grains became finer as amount of SiCP and mixing ratio of iron powder increased and the shape of compounds was changed gradually from irregular to spheroidal.
reactive sintering process, iron aluminide-Cu, Ni-P coated SiCp