Effect of SiC addition on Laser‑based CoNi Binary Alloy Coatings on Ti‑6Al‑4V alloy

Abstract

This research explores the impact of variations in laser scanning speed and the incorporation levels of SiC-Ni-Co powders on Ti-6Al-4V alloy using laser surface cladding technique. Key parameters, including a consistent laser power of 700 W, a 4 mm beam spot size, a powder feed rate of 1.0 g/min, and a gas fow rate of 3 L/min, along with fxed powder composi tions, were maintained. The laser scanning speeds were adjusted to 0.4 m/min, 0.8 m/min, and 1.2 m/min. Microstructural analyses were carried out using scanning electron microscopy (SEM) while Vickers microhardness was employed to assess coating hardness, and corrosion properties were evaluated using a linear potentiodynamic polarization technique. Follow ing the corrosion attack, the protective oxides formed were identifed through SEM and X-ray difractometer (XRD). The results revealed a strong metallurgical relationship between the clad layer and the substrate, demonstrating the efectiveness of the laser-clad technique. Particularly, the highest laser scan speed exhibited the most signifcant improvements in hardness and corrosion resistance. The coatings displayed an average hardness value of 1269.20 HV0.1, a notable fourfold increase compared to the substrate's value of 334 HV0.1. Concerning corrosion, a clear correlation emerged between scan speed and polarization resistance, confrming that higher scan speeds could lead to enhanced polarization resistance