Laser cladding of bioactive glass coatings (original) (raw)
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Journal of the Mechanical Behavior of Biomedical Materials, 2021
Free from toxic elements biomaterial potentially applicable for load bearing biomedical implants was obtained for the first time by laser cladding of S520 bioactive glass onto ultrafinegrained commercially pure titanium. The cladding process affected the refined structure of the substrate inducing martensitic transformation near its surface. The α' acicular martensite gradually passes into relatively large grains with increasing distance from the substrate surface, which subsequently are transformed into smaller grains of about 2 μm in diameter. Both the melted zone, where the martensite crystalline structure was found, and the HAZ are characterized by relatively lower hardness in comparison with that of the substrate core indicating increased ductility. Such a combination of zones with different properties may have a synergistic effect and is beneficial for the obtained biomaterial. A characteristic region in the form of about 3 µm width band was formed in the melted zone at about 10 µm below the titanium surface. The results of EDS analysis indicate that several glass elements moved into the region while the titanium content in the same area was decreased. High bioactivity of the coated S520 glass was revealed by in vitro testing with SBF solution and almost complete reduction of P concentration occurred after 14 days.
Bioactive Glass Coatings Synthesized by Pulsed Laser Deposition Technique
Acta Physica Polonica A, 2012
Surface modification of medical implants is often required to improve their biocompatibility or, through bioactive properties of the surface material, facilitate its intergrowth with the living tissue. Bioactive-glass coatings can serve that purpose for the bone implants. We report a successful preparation of silicate-phosphate bioactive-glass coating on titanium substrate using the pulsed laser deposition method and present the coating characterization in terms of bonding configuration and chemical activity. The former was studied with high-resolution Raman microspectroscopy and revealed the presence of structural units responsible for the material's bioactivity. The bioactivity was also tested directly, in vitro, by soaking the samples in the simulated body fluid and examining the result with the Raman spectroscopy. The Raman spectrum, typical of hydroxyapatite was observed proving that the bone-like-material formed on the coating's surface.
Structure, phases, and mechanical response of Ti-alloy bioactive glass composite coatings
Materials Science and Engineering: C, 2014
Porous titanium alloy-bioactive glass composite coatings were manufactured via the flame spray deposition process. The porous coatings, targeted for orthodontic and bone-fixation applications, were made from bioactive glass (45S5) powder blended with either commercially pure titanium (Cp-Ti) or Ti-6Al-4V alloy powder. Two sets of spray conditions, two metallic particle size distributions, and two glass particle size distributions were used for this study. Negative control coatings consisting of pure Ti-6Al-4V alloy or Cp-Ti were sprayed under both conditions. The as-sprayed coatings were characterized through quantitative optical cross-sectional metallography, X-ray diffraction (XRD), and ASTM Standard C633 tensile adhesion testing. Determination of the porosity and glassy phase distribution was achieved by using image analysis in accordance with ASTM Standard E2109. Theoretical thermodynamic and heat transfer modeling was conducted to explain experimental observations. Thermodynamic modeling was performed to estimate the flame temperature and chemical environment for each spray condition and a lumped capacitance heat transfer model was developed to estimate the temperatures attained by each particle. These models were used to establish trends among the choice of alloy, spray condition, and particle size distribution. The deposition parameters, alloy composition, and alteration of the feedstock powder size distribution had a significant effect on the coating microstructure, porosity, phases present, mechanical response, and theoretical particle temperatures that were attained. The most promising coatings were the Ti-6Al-4V-based composite coatings, which had bond strength of 20 ± 2 MPa (n = 5) and received reinforcement and strengthening from the inclusion of a glassy phase. It was shown that the use of the Ti-6Al-4V-bioactive glass composite coatings may be a superior choice due to the possible osteoproductivity from the bioactive glass, the potential ability to support tissue ingrowth and vascular tissue, and the comparable strength to similar coatings.
Applied Surface Science, 1999
Ž w . A study of the laser ablation and deposition, on Ti-Al substrates, of a biologically active glass Bioglass suitable for bone implants is reported. The analysis of the gaseous phase by emission spectroscopy and the characterisation of the films from a compositional and morphological point of view have been carried out. The mean chemical composition of the deposits obtained from Bioglass ablation is very close to the target composition and the morphology indicates that different mechanisms of material ejection are present. q
Bioactive calcium titanate coatings on a Zr-based bulk metallic glass by laser cladding
The bioactive calcium titanate coating was prepared by laser cladding on a (Zr 0.62 Cu 0.23 Fe 0.05 Al 0.1 ) 97 Ag 3 bulk metallic glass. The coating, which was mainly composed with dendrite calcium titanate and a little calcium pyrophosphate, formed a strong bonding with the substrate. The cladding process generated a crystallized heat-affected zone with a thickness of 300 μm and other parts in the substrate remained amorphous structure after laser cladding. It was demonstrated that surfaces of Zr-based bulk metallic glasses can be made bioactive and that laser cladding techniques were useful methods in the purpose of making Zr-based bulk metallic glass surface bioactive.
Fabrication of bioactive glass coating on pure titanium by sol-dip method: Dental applications
Dental Materials Journal
This study aimed to assess the mechanical and biological properties of bioactive glass (BG) coating on titanium (Ti). Bioinert Ti substrates were coated by BG to induce bioactivity to the surface. The sol-gel derived BG 58S sol was successfully prepared and coated on the abraded and blasted Ti surface using the sol-dip method. The characterization and cell study for all substrates' surface was carried out. Adhesion test confirmed that a firmly adhered BG coating layer was formed on the abraded and blasted Ti. The measured bonding strength between the coating and the blasted Ti substrate was the highest among all samples, which was 41.03±2.31 MPa. In-vitro cell viability and alkaline phosphatase activity (ALP) tests results also showed that BG coating on the Ti substrate improved the biological properties of the surface. The BG sol-dip coating method could be used to fabricate Ti substrate with a bioactive surface.
Flame Spray Deposition of Titanium Alloy-Bioactive Glass Composite Coatings
Journal of Thermal Spray Technology, 2011
Powders of titanium alloy (Ti-6Al-4V) and bioactive glass (45S5) were deposited by flame spraying to fabricate composite porous coatings for potential use in bone fixation implants. Bioactive glass and titanium alloy powder were blended and deposited in various weight fractions under two sets of spray conditions, which produced different levels of porosity. Coatings were characterized with cross-sectional optical microscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). Immersion testing in simulated body fluid (SBF) was conducted for 0, 1, 7, and 14 days. Hydroxyapatite (HA) was found on the bioactive glass-alloy composite coatings after 7 days of immersion; no HA was observed after 14 days on the pure titanium alloy control coating. The HA formation on the alloy-bioactive glass composite coating suggests that the addition of bioactive glass to the blend may greatly increase the bioactivity of the coating through enhanced surface mineralization.
Fabrication and characterization of a bioactive glass coating on titanium implant alloys
Acta Materialia, 1999
ÐOngoing research is reported aimed at improving bio®xation through the use of bioactive glass coatings on Ti-based implant alloys. The optimized processing conditions for coating with one promising bioactive glass composition are discussed, and the stress corrosion crack growth behavior in a simulated human physiological environment is presented. This glass can be successfully used to coat Ti implant alloys, and preliminary tests indicate that interfacial fracture resistance is good.
Bioactive glass coatings obtained by thermal spray: Current status and future challenges
2021
Several inorganic materials such as bioactive glasses, glass–ceramics and calcium phosphates have been shown to be bioactive and resorbable which make them suitable for coating bone implants. This study focuses only on bioactive glasses. These biomaterials are highly biocompatible and can form a strong chemical bond with the tissues. This review comprehensively covers bibliographic reports that have investigated bioactive glass deposition using different thermal spray techniques. The main drawback for the glass coating deposition is the low adherence with the substrate. Some strategies can favour a good bond such as using bond coats, blends, pre-heating the substrate or modifying the glass composition. The characteristics of the feedstock powders are determinant for the properties of the coatings obtained. Porosity and thickness of the coatings can be modulated by using different thermal spray techniques and varying parameters of the process. The degradation rate of some bioactive g...
Structure and bioactivity of Ti/bioactive glass ‘changing landscape coatings’
Surface Innovations, 2013
Porous titanium alloy-bioactive glass composite coatings were produced via flame spray deposition. The porous coatings, targeted for bone fixation and orthodontic devices, were made from bioactive glass (45S5) powder blended with one of two titanium powders: commercially pure titanium (Cp-Ti) or titanium alloy (Ti-6Al-4V). The coatings were characterized by cross-sectional quantitative metallography, optical microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The porosity and glassy phase distributions were determined by image analysis of optical micrographs, in accordance with ASTM Standard E2109. Selection of Cp-Ti or Ti-6Al-4V alloy, along with alteration of the particle size distribution of bioactive glass, dramatically changed the morphology and phases present within each coating. The consequences on the bioactive response were characterized with immersion testing in simulated body fluid for up to 14 d. The coatings were analyzed for the presence of hydroxyapatite (HA) after testing; HA formation was observed as soon as 7 d for Ti-6Al-4V-based composites, while no formation occurred on Cp-Ti-based composites. HA formation on the negative Ti-6Al-4V control coating was observed after 14 d, while formation was not observed on the Cp-Ti coating, suggesting that the incorporation of bioactive glass into flamesprayed Ti-6Al-4V alloy coatings enhances bioactivity. Surface Innovations Volume 1 Issue SI4 Structure and bioactivity of Ti/bioactive glass 'changing landscape coatings' Nelson, McDonald and Nychka Pages 209-223 http://dx.