Effects of layer thickness ratio on deformation coordination and dynamic softening mechanisms of hot-compressed 1060Al/SiC–6061Al/1060Al composites

The 1060Al/SiC–6061Al/1060Al laminated particle-reinforced aluminum matrix composites (LPRAMCs) have their deformation behavior affected not only by processing parameters but also significantly by the initial layer thickness ratio of their components. This ratio affects the interface structure, microstructure and mechanical properties of the material by affecting the physical properties and the strain partitioning during the deformation process. In this study, the flow behavior, interfacial structure, hot processing maps, and microstructural evolution of two LPRAMCs, designated as 363 and 444 composites with different layer thickness ratios, were systematically investigated under various deformation conditions via hot compression tests. Additionally, the influence of layer thickness ratio on deformation coordination and recrystallization mechanisms was analyzed. The results revealed that, under all deformation conditions, the 363 composites, which contain a higher proportion of the hard 6061Al–SiC particle-reinforced layer (PR layer), consistently exhibited higher flow stress than the 444 composites. Although the 363 composites displayed superior overall deformation coordination to the 444 composites, the coordinated deformation effect between the component layers in the 444 composites became more evident with increasing distance (i.e., strain) from the center to the edge of the sample. The different component ratios of the composites correspond to different deformation behaviors. The deformation mechanism of the 1060Al layer (Al layer) in the two composites was dominated by dynamic recovery (DRV), accompanied by partial continuous dynamic recrystallization (CDRX), whereas the PR layers primarily underwent CDRX. However, localized geometric dynamic recrystallization (GDRX) was observed in the PR layer of the 444 composite.