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Thermal spraying technologies are widely used to fabricate quality thick metallic and ceramic coatings for various applications. In all sectors of the industry today, demands better, faster and cheaper methods of production, as it seems that manufacturing demands are ever-increasing. However, if the coating thicknesses below 50 microns are demanded as the result of economic or technological requirements, this often constitutes a challenge for the established thermal spraying processes. For this purpose, in the present work, an attempt has been made to deposit a thin metallic coating below 40 microns by thermal spraying through wire feedstock materials rather than using an expensive powder as feedstock. For a broad spectrum of copper (Cu) applications, Cu is deposited on the low carbon steel substrates using fast, easy and economical Wire-High Velocity Oxy-Fuel (W-HVOF) thermal spray system (trade name-HIJET 9610). As-sprayed coatings were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) for phase and microstructural analysis respectively. Coating surface roughness and porosity were also measured. Adhesion strength tests were conducted to determine the bond strength of the as-sprayed coatings. Results show that the coating deposited by W-HVOF has acceptable properties and gain a direct economic advantage and time-saving process, often over established thin coating techniques like plating.

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The present study reports the novel results of microstructural and mechanical properties of highly porous Polyetheretherketone (PEEK) coating. PEEK is already considered as a material for biomedical implants. A new kind of approach is proposed for manufacturing of highly porous PEEK coating on a dense PEEK coating for orthopedic implants and successfully implemented to create novel biomimetic porous PEEK coating by means of thermal spray process. To imitate the structure of natural bone, as-sprayed top PEEK coating has porosity of more than 60% vol. and pore sizes of 30-80 μm. Mechanical results of dense PEEK coating show that PEEK coating exhibited good strength, hardness (20 HV0.1) and good bonding strength (15 MPa) with the metal substrate. Thermal sprayed porous PEEK coating that can be used for future implants instead of plasma sprayed titanium coating on dense PEEK implants because porous PEEK improves the bone-implant interface joining compared to plasma-sprayed titanium coating on PEEK.

All thermal spray coatings are finally deposited on a rough and active grit-blasted surface of the job. But, available literatures are reporting splat and flattening behavior on a polished surface. There is a gap in thermal spraying to understand actual solidification on a rough surface. Therefore, in the present work an attempt has been made to study of splat formation of thermally sprayed copper onto grit-blasted rough surface. An optimization study is done to collect rounded/semi-rounded disk like splats to set spray parameters. Optimized parameters were also tested at four different gun traverse speeds to fabricate thin Cu coatings (30-50µm).