| Budget Amount *help |
¥6,700,000 (Direct Cost: ¥6,700,000)
Fiscal Year 1987: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1986: ¥5,600,000 (Direct Cost: ¥5,600,000)
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| Research Abstract |
The present study aimed to develop ductile intermetallic compounds, based on the ductilization concept proposed by the present investigators. Furthermore, the correlations between atomic (electronic) structure and mechanical properties in these intermetallic compounds was analyzed.
1. Alloy design Some ductile L1_2-type compounds such as Co_3Ti, Ni_3(Si,Ti), Ni_3(Al,Mn) and Ni_3(Al,Fe) were predicted by the structural and electronical analysis for grain boundary of intermetallic compounds. Also, B2-type CoTi was shown to be deformable above room temperature. It was suggested that the ductilization and expansion of phase field of compound were, based on theory of phase stability, accomplished by the simultaneous additions of proper alloy elements.
2. Structural analysis Atomistic defect structures of some compounds were investigated in terms of the alloy stoichiometry. Alloying behavior such as solubility, occupation site and interaction with constituent atoms were investigated for additives of substitutionals and interstitials such as H,B and C. Also, point defect and line defect (dislocation) responsible for the peculiar mechanical properties of compounds were investigated by TEM and XDM techniques.
3. Mechanical properties. Mechanical properties of poly- and single-crystals of compounds mentioned above were investigated in terms of test temperature, composition, strain rate and test environment. Excellent, peculiar strength and ductility properties were found.
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