摘要
The mechanisms of fatigue crack propagation in intermetallics alloys, specifically γ TiAl, Nb 3Al and MoSi 2, were compared with corresponding behavior in brittle ceramics and ductile metals. This was achieved by considering the process of fatigue crack growth as a mutual competition between intrinsic mechanisms of crack advance ahead of the crack tip (e.g., alternating crack tip blunting and resharpening), which promote crack growth, and extrinsic mechanisms of crack tip shielding behind the tip (crack closure and bridging), which impede it. The differing nature of these mechanisms in brittle and ductile materials and their specific dependence upon the alternating and maximum driving forces (e.g., Δ K and K max ) provided a useful distinction of the process of fatigue crack propagation in these different classes of materials.
The mechanisms of fatigue crack propagation in intermetallics alloys, specifically γ TiAl, Nb 3Al and MoSi 2, were compared with corresponding behavior in brittle ceramics and ductile metals. This was achieved by considering the process of fatigue crack growth as a mutual competition between intrinsic mechanisms of crack advance ahead of the crack tip (e.g., alternating crack tip blunting and resharpening), which promote crack growth, and extrinsic mechanisms of crack tip shielding behind the tip (crack closure and bridging), which impede it. The differing nature of these mechanisms in brittle and ductile materials and their specific dependence upon the alternating and maximum driving forces (e.g., Δ K and K max ) provided a useful distinction of the process of fatigue crack propagation in these different classes of materials.
出处
《中国有色金属学会会刊：英文版》
CSCD
1999年第S1期214-227,共14页
Transactions of Nonferrous Metals Society of China
