ホットプレスしたTi₅Si₃基合金の硬さ試験を用いた室温・高温特性の検討

抄録

The effect of ductile second phase of Ti₅Si₃ base intermetallic compounds on mechanical properties was studied. In this study, α-Ti (hcp) or β-Ti (bcc) are chosen as the second phase. It is necessary to add ternary element to make the β phase stable at room temperature. Chemical compositions of materials investigated here are Ti-32mol%Si (Ti₅Si₃+α-Ti), Ti-32mol%Si-10mol%V (Ti₅Si₃+β-Ti) and Ti-32mol%Si-5mol%Mo (Ti₅Si₃+β-Ti), those were fabricated by mechanical alloying and vacuum hot pressing method. Mechanical properties from room temperature to 1373K were investigated by micro-Vickers hardness tester to show the effect of ductile phase and also ternary element, V or Mo. V addition was effective to increase fracture toughness, K_IC, at R.T. The K_IC value of Ti-32Si-10V compact was 4.43MPa⋅m^1/2 which was about 1.7 times larger than Ti₅Si₃ monolithic compact. Ti-32Si-5Mo compact behaved superior high temperature properties in comparison with Ti-32Si-10V compact.