The attempt to fabricate gold films on glass slide (Au/glass) and silicon wafer (Au/Si) with gold leaf was unsuccessful due to poor adhesion between the gold leaf and substrates. Alternatively Au/glass and Au/Si films were fabricated by placing the substrate into the free space within sputtering chamber to collect the access Au vapor during the typical sputtering process for other samples. In this study the physical changes were observed in both Au/glass and Au/Si film under the film annealing from 300⁰C-700⁰C. The visual inspection via cell phone camera the micrograph via Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) revealed the morphological changes with respect the annealing temperature in Au films due to solid state dewetting mechanism. The changes were more pronounce in Au/glass films than Au/Si films at the same annealing temperature. The X-ray diffraction measurement three phases of Au including Au(111) Au(200) and Au(220) in Au/glass films and one phase of Au(111) in Au/silicon films. The concentration and single crystallinity of Au(111) were increased with respect to annealing temperature in Au/glass film. For Au/Si films the concentration and single crystallinity of Au(111) were decreased at 300⁰C and then were increased at 700⁰C respectively. The physical changes of Au films are likely due to the movement of Au atoms via solid state dewetting and recrystallization. The heat intake from annealing process is likely induced the dewetting process by increasing the kinetic energy of Au atoms. While the recrystallization process is likely occur during the cooling period of the samples. Finally another factor that can affects the physical changes of Au films is the interface interaction between Au films and substrates.

This research article aims to study of the atomizer nozzle pattern in the gas atomization process. The production of metal powder by using a gas atomization process. It is the most popular process. This process is used in various industry and engineering application. However there is lack of information on the production of various precious metal powders in the jewelry manufacturing industry both in the country and abroad. For this reasons the research team is interested in applying this process for the Thai jewelry manufacturing industry. Currently the jewelry industry is in a transitional period of manufacturing technology with an increased focus on powder metallurgy technology. The production of metal powder by using a gas atomization process consisting of the following 3 steps: melting making of atomized molten metal cooling and solidifying for solid particles under a controlled gas atmosphere. Factors affecting particle shape particle size and particle size distribution are consisting of inert gas type molten metal temperature and the configuration or pattern of the nozzle that are different characteristics. The results can be concluded that Close-Coupled Nozzle is the most suitable nozzle for production due to the highest productivity providing the smallest particle size and spherical granular shape. The information from this study will be useful for the Thai jewelry manufacturing industry.