Interfacial Thickness-Induced Tensile Strengthening Effect of 3D-Printed Interactive Bimaterial Specimens

Functional materials fabricated by using 3D printing are an emerging and cutting-edge research branch in the field of advanced energy, and the mechanical behavior of bimaterial composites is crucial for designing structures with enhanced strength, toughness, and multifunctionality. In this work, the thickness-induced tensile strengthening effect in 3D-printed bimaterial specimens was investigated. Specimens with varying layer thicknesses were fabricated by using a vat photopolymerization (VPP) multimaterial 3D printing process, and tensile tests were conducted to analyze the impact of thickness on the interfacial interaction and overall tensile strength. The experimental results show that reducing the layer thickness of the specimen to 0.2 mm significantly enhances the tensile strength due to improved interfacial bonding and material synergy. The finite element model of the transition region with the equivalent interfacial layer is established based on the microscopic morphology at the interface. Finite element analysis confirmed the experimental results, showing that reducing the layer thickness is beneficial for enhancing tensile strength in bimaterial structures.