Ceramic injection moulding: influence of specimen dimensions and temperature on solvent debinding kinetics

Ceramic injection moulding (CIM) has been the process selected for the production of complex ceramic components in recent years. In this process, binder removal is one of the most critical steps due to the possible appearance of defects. In this study, the influence of specimen geometry and temperature on the solvent debinding step of an as-moulded specimen was investigated. Green specimens with different bulk surface area to volume ratios (As/V) were maintained in hexane at 20, 40 and 60 °C, and the weight losses were evaluated as a function of time. The kinetic study showed an increase in weight loss rate with increasing As/V ratio and solvent temperature. A mathematical model was proposed to predict debinding kinetics of specimens with known As/V ratios at different temperatures. Specimens were also submitted to porosity analysis and electronic microscopy to evaluate their characteristics during and after solvent debinding.