연소합성법에 의한 $MoSi_2-Al_2O_3$ 복합재료의 특성에 미치는 $Mo/MoO_3$ 몰비의 영향 |
장윤식, 이윤복, 김용백, 김인술1, 박흥채2, 오기동 |
부산대학교 무기재료공학과 1포항산업과학연구원 2부산대학교 무기재료공학 |
Influences of the Molar Ratio of $Mo/MoO_3$ on Characteristics of $MoSi_2-Al_2O_3$ composites by SHS Methods |
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ABSTRACT |
MoSi2-Al2O3 composites were prepared by thermal explosion mode of self-propagating high temperature syn-thesis (SHS) using element powders of MoO3 Mo Si and Al. The combustion products of MoSi2 which have 10, 20, 30 and 40 wt% Al2O3 showed the molten state in the range of Mo to MoO3 6:1-9.5:1, 2:1-8:1, 1:1-5:1, and 1:1-3:1 (molar ratio) respectively. The combustion products which made least seperation the molten phase from the slag phase were in Mo/MoO3=9, 5:1, 8:1, 5:1 and 3:1 (molar ratio) respectively. Particles size of MoSi2 and Al2O3 in the combustion product were decreased as the molar ratio of Mo to MoO3 increase. By XRD analysis only MoSi2 and $alpha$-Al2O3 peaks were identified in the combusion products, In case of MoSi2 containing 20wt% Al2O3 5.1wt% Al existed into MoSi2 grains and 30.7wt% Si and 7.7wt% Mo existed into Al2O3 grains. The relative density of MoSi2 containing 10, 20, 30 and 40 wt% Al2O3 were 82.7, 85.2, and 81.9% respectively. The fracture strength of MoSi2-Al2O3 composites increased with increasing Al2O3 and that of MoSi2-20wt% Al2O3 composite was 195 MPa. |
Key words:
$MoSi_2-Al_2O_3$ composites, Thermal explosion mode of SHS, The molar ratio of Mo to $MoO_3$ |
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