Laser coating of bioactive glasses on bioimplant titanium alloys

Abstract

Laser-assisted material processing is a promising field for new material synthesis. This study explores the feasibility of using laser as a tool to synthesize SiO 2 -Na 2 O-CaO-P 2 O 5 bioactive glass coatings on Ti-6Al-4V alloy for bio-implant application. Various laser processing conditions were explored to investigate their effects on coating characteristics. Detailed microstructure and elemental distribution on the top surface and in the cross-sectional region of the bioactive glasscoated alloy were investigated by scanning electron microscope and energy dispersive spectroscopy. Bio-mineralization in simulated body fluid for both representative-coated samples and uncoated control sample for comparison was carried out. The thermokinetic effects during laser processing were simulated using a multi-physics finite element model. The results demonstrated synthesis of bioactive glass coating on the metal substrate with local segregation of Na, P, and Si elements and considerable dilution of Al and Ti in the coating from the alloy substrate impacted the bioactivity of the coating. Although the observations suggest that the laser processing is a promising method in applying bioactive glasses coatings, further efforts are warranted to optimize laser processing conditions to produce adherent coating while retaining its bioactivity. K E Y W O R D S

Bioactive glass coatings on metallic implants for biomedical applications

“…Comparing to the conventional surface modification techniques, laser technique not only conducting fast surface modification with high resolution but also taking care of advantages as mention above [[39], [40], [41], [42], [43], [44]]. Moreover, considering short laser beam-material interaction times (milliseconds to few seconds), Krzyzanowski et al predicted the evolution of thermokinetic conditions and thermal stresses during the laser-assisted synthesis of bioactive glass coating on Ti-based alloys using a comprehensive computational model and primary experimental observations [102].…”

“…Additionally, it was noted that the presence of the titanium alloy particles also increased the interleukin-1, interleukin-6, and tumor necrosis factor. Whereas, the chromium-cobalt alloy particles reduced the release of prostaglandin E2 and interleukin-6, while it had little effect on the release of interleukin-1 and tumor necrosis factor [[39], [40], [41], [42], [43], [44]]. Therefore, it is safe to say that cobalt-chromium is a superior choice over titanium and its alloys for large joint replacement applications.…”

Bioactive Glass—An Extensive Study of the Preparation and Coating Methods

“…The powder or paste material can also be deposited on the surface of the substrate, then melted with a laser beam [162]. Bioactive glass coatings obtained using this technique were applied to Ti-6Al-4V alloy substrates [163,164]. In addition to the 45S5 bioactive glass, S520 type bioactive glass coatings were obtained.…”

Effect of boron oxide on mechanical and thermal properties of bioactive glass coatings for biomedical applications

“…Recently, laser‐assisted coating has been used to apply bioactive glass coatings on metal implants, high laser energy melts bioactive glass and metal to form a cladding layer and prompts a strong interfacial bonding 19,47,48 . However, the high energy density also induces tensile stress and elemental dilution between the glass and the heat affect zone of metal, which changes the chemical composition and microstructure of the glass and can decrease the biological response 48–50 . Thus, it is clear that designing bioactive glass coating for metal implants is a challenging task due to large design parameter space of potential glass compositions, various targeted thermal, mechanical, and bioactivity properties, and available coating methods.…”