| Intermetallic compounds based on Ti_5Si₃ were made by reactive sintering(RS) alone or in combination with pseudo-hot isostatic pressing(PHIP) and their density variation with sintering parameters was studied. Adding Cu, selected as a sintering aid on the ground of the `figure of merit` theory, increased the density significantly during reactive sintering, presumably due to the role of Cu in increasing the inter-solubility of the base metals and catalyzing their diffusivity during sintering. The sintered density could be increased by decreasing the particle size of the elemental powders and increasing the sintering heat treatment time. The maximum relative sintered density, about 93%, was obtained under a condition of 6wt.% Cu, small particle size and 7h of holding time at 1450℃. Also, the sintered density of the Ti_5Si₃ base intermetallic compound could be remarkably improved by using the method of PHIP. A sintered density of approximately 99% was obtained by compacting at 1250℃ for 2h under a pressure of 250MPa, which was explained in terms of adequate particle rearrangement and effective removal of pores aided by the external pressure during the densification process. |
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