Influence of multisteps thermal control in metal powder injection moulding process

摘要

In metal injection moulding, the quality of the products depends highly on an effective and suitable debinding process. The improvement of the debinding process thus becomes one of the most important topics in metal injection moulding research. To increase the binder debinding rate and decrease the defects of the products, it is essential to understand the influence of thermal control on the debinding process. The present paper aims to investigate the effect of multisteps thermal control on the debinding rate through experiments. Different from previous researches in which single binder is usually adopted, multicomponents binder is used to reflect the real manufacturing situations in industry. The relationship among viscous force, capillary force and pressure force for different working conditions is discussed in details. Experimental results show that the debinding rate and the final debinding fraction are dominated by particle size in the compact rather than that in the wick. For thick compact with low porosity, the shape of green compact is well maintained and the defect of neck shrinkage is reduced by multisteps thermal control. The neck shrinkage situation can further be improved by using the two component binder.