분말야금법에 의한 Ti3Si3계 금속간화합물의 합성연구

초록

Ti5Si3 intermetallics containing 0∼6wt% of Cu were made by reactive sintering(RS) under vacuum using elemental powder mixtures(Processl1), electro-pressure sintering(EPS) using RS'ed materials(Process2), EPS using elemental powder mixurtes(Process3) and EPS using degassed elemental powder mixtures(Process 4). Relatively low dense titanium silicides were gained by Process 1, in which porosity decreased with increaing Cu content. For example porosity changed from 42 to 19.4% with the increase in Cu content from 0 to 6wt%, indicating that Cu is a useful sintering aid.. The titanium silicides fabricated by Process 2 had a higer density than those by Process 1 at given compositon, and porosity decreased with increasing Cu content. For example, porosity decreased from 38 to 6.8% with the change in Cu content from 0 to 6wt.% A high dense titanium silicides were obtained by Process 3. In Process 3, porosity decreased a little by Cu addition, and was almost insensitive to Cu content. Namely, about 9 or 7% of porosity was shown in 0 or 1∼6wt% Cu containg silicides, respectively. At given composition and holding time during EPS, the materials fabricated by Process 4 had a higher density than those by Process 3, which clearly indicates that the degassing process is an important controlling factor for densification. In Process 4, if holding time is chosen as 12 minutes, nearly full-dense materials(about 2% of porosity) were achieved irrespective of sintering aids. All these results suggst that process 4 is the best fabricated method to achive dense titanium silicides.