单相组织金属间化合物的超塑性行为

Superplastic Behavior of Single-Phase Intermetallic Compound

在一定条件下具有单相微观组织的 L 12 型 [Ni3 Al,Ni3 (Si,Ti) ,Co3 Ti],L 10 型 (Ti Al)和 B2型 (Fe Al,Fe3 Al,Ni Al)金属间化合物均表现出超塑性行为。其中 ,L 12 型和 L 10 型金属间化合物的超塑性变形机制为晶界的滑移 ,而 B2型金属间化合物的超塑性变形则来自于变形过程中发生的动态回复及再结晶。超塑性变形机制的多样性是由于金属间化合物在微观组织及位错结构上 (如反向畴界能、层错能和化学成分差异、超位错及界面位错等 )比普通金属合金要复杂得多。

The superplasticity of L1 2 structure [Ni 3Al, Ni 3(Si,Ti), Co 3Ti], L1 0 structure (TiAl) and B2 structure (FeAl, Fe 3Al, NiAl) in single phase intermetallic compound was reviewed. The superplasticity of these intermetallic compound possess all characteristics of conventional superplastic materials. The superplasticity of L1 2 structure and L1 0 structure stems from the grain boundary sliding, while the dynamic recovery and recrystallization are the superplastic deforming mechanism for B2 structure. The multi mechanisms of superplasticity arise from the microstructural and dislocation characteristics of an ordered intermetallic compound, such as anti phase boundary, stacking fault, compositional difference, superdislocation and interfacial dislocation, are much more sophisticated than those of a monolithic metal alloy.