|
Vol.42, No.2, 135 ~ 143, 2004
|
| Title |
| Microfracture Mechanisms of Zr-Base Bulk Amorphous Alloys Fabricated by Strip Casting |
| 이정구 Lee Jeong Gu , 이동근 Lee Dong Geun , 이성학 Lee Seong Hag , 김낙준 Kim Nag Jun , 조경목 Jo Gyeong Mog , 박익민 Park Ig Min |
|
|
|
| Abstract |
| The mechanical property improvement of a strip-cast Zr-base bulk amorphous alloy was explained by clarifying fracture mechanisms. Effects of crystalline phase particles formed in the amorphous matrix during strip casting on strength, ductility, and fracture toughness were explored in detail by directly observing microfracture processes using an in situ loading stage installed inside a scanning electron microscope (SEM) chamber. The compressive and fracture toughness test results indicated that ductility, strength, and fracture toughness of the atrip-cast amorphous alloy were higher than those of the as-cast monolithic amorphous alloy, although the strip-cast alloy contained a considerable amount (4.5 vol. %) of hard, brittle crystalline particles. This improvement of mechanical properties in the strip-cast alloy could be plausibly explained by mechanisms of (1) blocking of crack propagation, (2) formation of multiple shear bands, and (3) crack deflection by crystalline particles. Such property improvement presents new applicability of the strip-cast amorphous alloy containing crystalline particles to structures and components requiring excellent fracture toughness. |
|
|
| Key Words |
| Bulk amorphous alloy, Strip casting, Crystalline particle, Multiple shear band, Crack deflection |
|
|
 |
|
