Optimization of Bioglass 45S5 coating on 316 stainless steel via ultrasonic vibration assisted laser cladding for improved surface properties

Abstract

The demand for advanced medical implants has led to extensive research on enhancing their performance, durability, and biocompatibility. Bioactive glass 45S5 has emerged as a promising coating for metallic implants due to its bioinert properties and interaction with bone tissue. Laser cladding offers precision and minimal mechanical damage, but challenges such as porosity, residual stress, and cracking persist. Ultrasonic vibration, integrated into the laser cladding process, mitigates these issues by reducing defects and improving adhesion. This study employs ultrasonic vibration-assisted laser cladding to deposit bioactive glass 45S5 coatings on SS316 medical implants. The optimal laser processing condition was identified at 110 A amperage, resulting in an acceptable level of surface roughness coupled with superior wettability. Interestingly, lowering the pulse width parameter resulted in a more uniform melting pool and improved surface roughness, but did not significantly impact wettability. The best sample for surface roughness (6.2 µm) was achieved with laser current of 100 A, vibration amplitude of 10 µm, and pulse width of 6 ms. Similarly, the highest wettability (contact angle of 54.62°) was observed with laser current of 110 A, vibration amplitude of 10 µm, and pulse width of 6 ms. This work marks a significant advancement in bio-compatible implant coatings by demonstrating that ultrasonic vibration enhances surface properties, making it a viable technique for biomedical applications.