Insight to the plastic deformation behavior of a laminated particle reinforcement magnesium-based heterostructured material

Particle-reinforced magnesium matrix composites typically suffer from a trade-off between strength and ductility. Here, we fabricate a laminated heterostructure via additive manufacturing, comprising alternating hard regions (TC4 particle-reinforced AZ31 magnesium matrix composites) and soft regions (AZ31 alloy). This design achieves an improved strength-plasticity synergy through cooperative plastic deformation between the hard and soft regions. The hard regions are formulated with three TC4 particle contents: TS-1 (2.18 vol%), TS-5 (10.87 vol%), and TS-7 (17.49 vol%). The microstructure exhibit equiaxed grains, with no interfacial reactions or detectable defects at the particle/matrix interfaces. Al₈Mn₅ precipitates are uniformly dispersed within the AZ31 alloy matrix. The TS-1 specimen delivers an ultimate tensile strength of 247.1 MPa and an elongation of 13.8%. In contrast, the TS-7 specimen shows pronounced particle agglomeration and interfacial debonding. Both experimental and simulation results reveal that strain localized at the particle/interface matrix and the strain mismatch increases with the increase particle content. The primary extra strengthening mechanism is hetero-deformation induced (HDI) strengthening, arising from strain mismatches at both the particle/matrix interfaces and the interfaces of the laminated structure. Moreover, the laminated structure plays a critical role in strain transfer, helping to suppress strain localization and thereby enhancing the overall mechanical performance.