In the pack-cementation process, the parts to be coated are placed inside a vented or purged retort and embedded in a pack mixture consisting of an inert powder (e.g., aluminum oxide), a source (e.g., pure or pre-alloyed aluminum), and typically a halide activator salt to generate the transporting vapor species. _gaq.push(['_trackPageview']); In the chemical vapor deposition (CVD) process, the coating deposition reaction takes place at the part surface. Levine, S.R., and R.M. This phenomenon is determined through the different perception angle. A low or high viscosity influences the final aspect of the coating. Herewith the coating is tested on colour- and gloss retention. Serpentine cooling is also being considered. Goward, G.W., and D.H. Boone. d.write('