Work-softening mechanism of Cu-Cr-Ti-Si alloy

Abstract

The Cu-Cr-Ti and Cu-Cr-Ti-Si alloy ingots were melted in the atmosphere, and then treated with hot rolling-solid solution-aging-cold rolling process. Microstructure and properties of alloy after cold rolling with different deformation were studied. The microstructure of the alloy after cold rolling was analyzed by using OM,electron backscatter diffraction, X-ray diffraction and transmission electron microscopy. The results show that when the deformation ε is greater than 80%, the hardness of Cu-Cr-Ti-Si alloy is decreased. Such phenomenon does not occur in Cu-Cr-Ti alloy. With the increase of deformation, the proportion of low angle grain boundaries in Cu-Cr-Ti-Si alloy is decreased, and the increase of dislocation cells and sub-grains leads to slight decrease of dislocation density. Since no re-crystallization was observed, recovery is responsible for work softening. By analyzing the microstructure before cold rolling, it is found that Si can refine the alloy grains, resulting in smaller grains of Cu-Cr-Ti-Si alloy than Cu-Cr-Ti before deformation. More grain boundaries per unit area provide more energy storage at nucleation sites for recovery during deformation of the alloy.

Keywords

• cu-cr-ti
• cu-cr-ti-si
• work-softening
• recovery
• dislocation density
• grain refinement