Effects of processing parameters on joining strength of 316L-Cu interface in multi-materials laser powder bed fusion

Abstract

This study examines the impact of processing parameters on the joining strength and interfacial characteristics of 316L stainless steel-copper (Cu) interfaces fabricated using laser powder bed fusion. The integration of 316L and copper is critical for engineering applications that require a combination of mechanical strength, thermal conductivity, and corrosion resistance. Systematic experiments are conducted to evaluate the effects of varying laser power and scanning speed on interfacial properties. The 316L-Cu interfaces are characterized using optical microscopy, energy-dispersive X-ray spectroscopy (EDS), and microhardness testing to assess morphological and elemental features. A lap shear test was conducted to evaluate the mechanical strength of the joint, revealing an ultimate shear strength of 42.95 MPa for the sample with the optimal printing parameters in this work. The results indicate that increased volumetric energy density enhances interfacial bonding by promoting elemental diffusion and reducing porosity. However, challenges such as residual stresses and thermal expansion mismatch still affect interface quality. This research provides insights into the optimization of laser powder bed fusion parameters to improve the mechanical performance and reliability of multi-material components, advancing their applicability in diverse industrial sectors.