Ti-13V-11Cr-3Al合金の変形・破壊過程のSEM内その場観察
1992 年 78 巻 4 号 p. 673-679
詳細
1992 年 78 巻 4 号 p. 673-679
The deformation and fracture behavior of the aged microstructure of Ti-13V-11Cr-3Al alloy was studied by SEM in-situ observation. Comparing with beta matrix, the areas where alpha phase precipitates i.e. alpha colonies and the neighborhoods of grain boundaries show higher resistance to deformation. Thus, strength becomes higher by increase of alpha precipitates with aging. In the fracture of this alloy, a main crack propagates with forming microcracks within alpha colonies and along grain boundaries ahead of the main crack and joining them. The crack propagation along grain boundaries is faster and less ductile than the transgranular crack propagation following microcracks in alpha colonies. With development of aging, the grain boundary cracking becomes prevailing as a fracture mechanism, hence, ductility reduces notably. Alpha precipitates play an important role not in strengthening but also in fracture of this alloy.
