1994 Fiscal Year Final Research Report Summary
Mechanisms of deformation and fracture of intermetallic compounds
| Project/Area Number |
04239105
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
|
| Allocation Type | Single-year Grants |
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
YAMAGUCI Masaharu Kyoto Univ., Grad.School, Dept.Mater.Sci.&Eng., Prof., 工学研究科, 教授 (90029108)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MORI Hirotaro Osaka Univ., RCUHVEM, 超高圧電顕センター, 教授 (10024366)
UMAKOSHI Yuukichi Osaka Univ., Dept.Mater.Sci.Eng., Prof., 工学部, 教授 (00029216)
KIKUCHI Makoto Tokyo Inst.Tech.Univ., Dept.Metall.Eng., Prof., 工学部, 教授 (30089817)
OIKAWA Hiroshi Tohoku Univ., Dept.Mater.Sci., Prof., 工学部, 教授 (30005243)
TAKEUCHI Shin Univ.of Tokyo, Inst.Solid.Stat.Phys., Prof., 物性研究所・所長, 教授 (60013512)
|
|---|
| Project Period (FY) |
1992 – 1994
|
| Keywords | Intermetallic Compounds / Aluminides / Silicides / Lattice Defects / Deformation / Slip System / Fracture |
|---|
| Research Abstract |
The mechanical properties of high-temperature aluminides and silicides of transition metals, in particular, TiAl (gamma) /Ti_3Al (alpha_2) two-phase alloys and MoSi_2 have been intensively investigated.
Polysynthetically twinned (PST) crystals of binary and some ternary two-phase TiAl alloys with the lamellar structure derived from a single alpha-phase grain have been grown and the effect of lamellar orientation on their deformaiton and fracture behavior has been investigated. Such deformation experiments of PST crystals in uniaxial tension and compression have resulted in considerable progress in our understanding of the basic deformation behavior of two-phase TiAl alloys, in particular in the lamellar form. The mechanical properties of two-phase TiAl alloys in the lamellar form are quite anisotropic with respect to the lamellar orientation. Such anisotropic nature of mechanical properties sould be in use to develop two-phase TiAl-base alloys with a good balance of mechanical properties. Thus, the prospects of the DS-processing of two-phase TiAl-base alloys have been investigated.
The deformation behavior of MoSi_2 single crystals has been studied as a function of crystal orientation in the temperature range from -196 to 1500ﾟC in compression. It has been found that [001] -oriented crystals cannot be plastically deformed below 1300ﾟC,however, single crystals with orientations away from [001] can be plastically deformed even at temperatures as low as room temperature. The brittleness of polycrystalline MoSi_2 is believed to be closely associated with the difficulty in the plastic deformation for the [001] orientation at low temperatures.
Results which are both fundamentally and industrially interested have been obtained not only on TiAl and MoSi_2 but also other aluminides and silicides.
|
