2195 Al-li Alloy On The Microstructure Evolution In The Process Of Dynamic Loading

Split Hopkinson pressure bar (SHPB) was used for dynamic loading in hat-shaped specimen of natural aging2195aluminum-lithium alloy. The thermal/mechanical parameters during dynamic loading were calculated by dynamic loading voltage plus time curve. The microstructure and precipitate evolution within shear band were studied by means of TEM. The result shows that adiabatic shear band formed in shear zone during dynamic loading. In the boundary of shear band elongated subgrains were observed and equiaxed nanograins were observed in the center of shear band. No precipitates and dislocation walls were observed within shear band. Recrystallization occurred within shear band.Split Hopkinson pressure bar (SHPB) was used for dynamic loading in hat-shaped specimen of T6peak aging2195aluminum-lithium alloy. The thermal/mechanical parameters during dynamic loading were calculated by dynamic loading voltage plus time curve. The microstructure and precipitate evolution within shear band were studied by means of TEM. The result shows that adiabatic shear band formed in shear zone during dynamic loading. In the boundary of shear band elongated subgrains were observed and equiaxed nanograins were observed in the center of shear band. No precipitates were observed within shear band. Recrystallization occurred within shear band. The adiabatic shear band were compared between natural aging and T6peak aging status.The microstructure within adiabatic shear band of natural aging and T6peak aging2195aluminum-lithium alloy have the same morphology. Rotational dynamic recrystallization (RDR) mechanism was used to explain the possibility of grains refinement within adiabatic shear band in kinetics. A dissolution model of precipitate was suggested to explain the dissolution process of precipitates in adiabatic shear band during dynamic loading.