大型部材のパルス通電加圧焼結とその応用に関する研究

抄録

We have investigated the relationship between a sintering condition of TiAlSi mixed powder and microstructure of the sintered compact for the purpose of fabricating large target (such as 160mm x 100mm). The pulse current pressure sintering (PCPS) method was employed in order to consolidate the mixed powders consisting of Ti₅₀:Al₄₀:Si₁₀ (atomic %). The Ti₅₀Al₄₀S_i10 compacts were sintered under the variation of pressure (49～98MPa) and temperature (773K ～873K). When sintering temperature was 833K or higher, Al-Si liquid oozed out from the sintered compact. On the contrary, when the temperature was 833K or higher, many micro pores have formed in the sintered compact. Higher sintering pressure (60MPa or higher) increased the relative density of the compact and caused the formation of metallic compound in the interface of Ti and Al/Si. Relatively high density consolidation of 97% for Ti₅₀Al₄₀Si₁₀ mixed powder was obtained from the compact sintered at 823K under the pressure of 60MPa. Water quenching test revealed that this sintered compact had relatively high resistance of thermal shock due to the formation of little amount of metallic compound. Disk compacts of Φ190mm ×8mm were obtained and 160mm ×100 mm rectangular sputtering targets were fabricated from these disk compacts under the proper condition of PCPS.

Then we investigated that microstructure and mechanical properties of Ti-Al-Si-N films deposited from the rectangular targets to confirm whether the targets are useful for sputtering. The Ti₅₀Al₄₀Si₁₀ targets were sputtered in a mixture of argon and nitrogen using an r.f. sputtering apparatus of Facing Target-type Sputtering. The highest hardness of 43GPa was obtained for the Ti-Al-Si-N films deposited at 573k without substrate bias. The hardness or the films is～20% higher than that for Ti-Al-N films. These results indicate that the Ti₅₀Al₄₀Si₁₀ compact sintered by PCPS was useful and favorable for the sputtering target.