Suspension Plasma Spraying SPS

Important process parameters to consider are the viscosity of suspensions as a function of solid particle loading as well as deposition rates that can be achieved. 

Evaporation of fluid phase and particle transport towards centre of droplet 

Critical parameters Viscosity Solid content Droplet diameter Diffusion rate of particles, tp Vapour pressure Temperature Evaporation rate, tE 

Dense coating Dense coating Porous coating Hollow spheres 

Ca(OH)2, respectively. The mechanical properties of the deposits such as critical load, scratch hardness and friction coefficient were determined by scratch testing under loads of 3-9 N. The coatings sprayed onto titanium alloy indicated critical load of 12.3 N and the ones onto aluminium substrate were lower and equal to 10.5 N. 

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Figure 5.29 Schematics of a suspension plasma spraying (SPS) apparatus.

Figure 5.30 Processural steps occurring during suspension plasma spraying (SPS). Processes are indicated by italics. (Modified after Muller (2001).)...

Figure 5.32 SEM images of conventional atmospheric plasma sprayed (APS, left) and suspension plasma sprayed (SPS, right) hydroxyapatite coatings, (a, b) Top view and (c, d) coating cross-sections (Gross and Saber-Samandari, 2009). ( With permission by Elsevier.)...

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