Processing effect on microstructures and flexural response of AlSi10Mg/AA 6061 multi-material fabricated by laser powder bed fusion

This study investigates the microstructure, tensile, and bending properties of AlSi10Mg/AA6061 bimetals fabricated via Laser Powder Bed Fusion (LPBF) in both butt and laminate configurations. Microstructural analysis reveals an interfacial zone, 40–100 μm thick, exhibiting strong metallurgical bonding facilitated by Marangoni convection and silicon diffusion. Tensile tests indicate ultimate tensile strengths (UTS) ranging from 307 to 314 MPa. Three-point bending tests highlight a configuration-dependent performance: laminated specimens with AA6061 under tension achieve exceptional bending strength (655 MPa, approximately 2 % higher than monolithic AlSi10Mg) and an elongation of 12.5 %, matching the ductility of AA6061. In contrast, butt joints exhibit minor strength reductions (596 MPa), due to small interfacial microcracks resulting from residual stresses. Digital image correlation confirms that strain localization patterns are governed by material modulus and hardening characteristics.