Experimental and failure analysis of the mechanical and fatigue properties of laser assisted hybrid stainless steel-thermoplastic composites joints

Combining different types of materials increases its importance in lightweight component studies. However, conventional joining methods cannot provide perfect joining of dissimilar materials. In this context, glass fiber-reinforced Elium based thermoplastic materials and an AISI 304 stainless steel have been joined using laser-hybrid joining. After the joining operation, mechanical characterization tests (lap shear, compression shear, and three-point bending) were performed on coupon samples. In addition, after the tests, the joint grids have been examined and the failure type (cohesive/adhesive/mixed) has been analyzed. Moreover, fatigue tests have been applied to highlight the endurance of tensile-tensile loading condition. Finally, as a result of all these tests, it was determined that the laser-assisted bonding has a lap shear strength of nearly to 18 MPa and a fatigue life of up to 10⁶ cycle at 30% UTS. As a result of all these tests, it was determined that the material maintains its strength in both dynamic tensile-tensile loading and static mechanical tests with the laser hybrid joining.