The investigation of the effects of debinding time and dimensions of sample on parts produced from tungsten carbide by powder injection molding

Powder injection molding (PIM) is a method that is emerged from the combination of conventional powder metallurgy technique and plastic injection molding. This method, comprises four basic steps including of preparation of the feedstock, injecting into the mold,the binder removal process and sintering. The binder removal process in PIM effects the ultimate strength achieved in part after sintering. Also if the debinding time is selected as higher than optimum level, production cost will increase, obviously. Therefore, determination of loss of mass that occurs during binder removal process is significant. In this study, tungsten carbide (WC) samples with three different diameters (4,3; 9,75 ve 12 mm) and three different lengths (15, 14, ve 11 mm) were produced by PIM method. Then these samples were subjected to chemical debinding process at four different time, 24, 48, 60 and 72 hours, respectively. Ethanol was used as solvent in the chemical binder removal process, As a result of experiments, the effects of sample thickness, volume, surface area/volume ratio (Ay / V) and debinding time on weight loss were specified by using PIM. According to the this study, as the surface area/volume ratio (Ay / V) is increased the weight loss will increased, while the thickness and volume are increased, weight loss will decreased for the green part of the feedstock. 60 hours is determined as optimum binder removal parameters for the case of 60°C in ethanol