Nitriding response of microminiature powder injection molded titanium

The gas-nitriding mechanisms effective in sintered titanium parts produced by metal injection molding (MIM) were investigated. The thermal debinding, sintering, and nitriding were performed continuously in a vacuum and gas-atmosphere furnace. Sintering was performed at 1,150°C, 1,200°C, and 1,250°C for 2 h and nitriding parameters of time and partial pressure in the furnace were investigated at 1,250°C temperature. The nitrogen content of the specimens was evaluated by means of the weight increase of the specimen. The microstructures and impurities in the sintered-and-nitrided specimens were evaluated by means of optical microscopy (OM) and elemental analysis using electron microprobe analysis (EMPA). The results showed that the sintered density increased with an increase in the sintering temperature and the nitrogen content increased with the decrease in specimen thickness and decrease in sintering temperature.