Gas Nitriding Mechanism in Titanium Powder Injection Molded Products

_Materials Science Forum 534-536:361-364 _ January 2007

Abstract.Gas surface treatment is consideredto be especially effective for Titanium because of itshigh reactivity. In this study, weinvestigatedthe gas nitriding mechanism in titanium sintered parts produced by metal powder injection molding (MIM) process. In MIM process, gas nitriding can be surface-treated subsequently after debinding and sintering process. Then,the microstructure and nitrogen content of sintered MIM parts are considered to be greatlyinfluenced by not only nitriding conditions but also sintered conditions. In this study, the effects of sinteringtime on microstructure such as nitrided layer thickness and hardness wasinvestigated. Focus was given to theeffects of specimen size on nitriding process, because the size of micro metal injection molding (μ-MIM) product is so small and the specific surface of that product is so large that the mechanical and functional properties can be subject to changeby nitriding.