Enhancing steel-on-aluminum wire laser cladding through laser-induced surface texturing and response surface methodology

Stainless steel laser cladding on aluminum substrates is severely restricted by poor metallurgical compatibility and the formation of brittle Fe–Al intermetallic compounds. To address this challenge, this study proposes a novel hybrid approach that combines laser surface texturing with coaxial wire laser cladding (1.2 kW diode laser operated at 1024 W), in which the substrate topology is engineered to regulate heat transfer, melt pool behavior, elemental diffusion, and mechanical interlocking without modifying the laser processing parameters. A combined experimental, statistical, and numerical investigation was conducted using a Central Composite Design (CCD) to optimize texture width (50–350 μm), distance (125–575 μm), and depth (160–640 μm), while evaluating bond strength, dilution rate, contact angle, clad height, and clad width. Response surface methodology and multi-objective optimization demonstrated that the surface texture geometry strongly influenced bond strength, dilution, contact angle, and clad geometry. Within the CCD experiments, the measured bond strength ranged from 7.9 to 87.3 MPa, and the dilution rate ranged from 16.53 to 41.31%, demonstrating the strong dependence of interfacial and geometrical responses on the texture parameters. The optimized texture (180 μm width, 488 μm distance, and 4T (320 μm) depth) yielded an experimentally validated bond strength of 61.7 ± 7 MPa and a dilution rate of 19 ± 2%, together with controlled clad geometry and contact angle. Additional validation experiments identified a deposition speed of 10 mm/s as providing the most stable clad geometry. Profilometer, metallographic, EBSD, and EDS analyses confirmed enhanced geometric uniformity, controlled aluminum diffusion, and improved interfacial integrity.