Microstructural evolution and strengthening of 40% SiCp/Al composites fabricated by rolling-assisted resistance seam additive manufacturing

This study systematically investigates the influence of rolling treatment on the microstructural evolution and mechanical properties of 40 vol% SiCp/AlSi10 Mg composites fabricated via resistance seam additive manufacturing (RSAM). The experimental results demonstrate that interlayer rolling effectively eliminates macroscopic pores through intense plastic deformation while simultaneously fragmenting SiC particle agglomerates. This process yields a pre-densified microstructure with significantly fewer defects, which facilitates the subsequent hot isostatic pressing (HIP) process in further eliminating residual micro-pores. Consequently, the interfacial metallurgical bonding and overall mechanical properties are significantly enhanced. Compared with the R0 sample, the rolling + HIP samples exhibit a reduced porosity of 0.75% (a decrease of 44%), while the ultimate tensile strength (UTS) increases substantially from 97.95 MPa to 226.16 MPa. The combined process clearly produces a synergistic effect. These findings demonstrate that rolling treatment serves as an effective pre-densification and microstructural regulation strategy, playing a crucial role in the fabrication of high-performance aluminum matrix composites.