Kinetic Modelling of thermal debinding & sintering in MIM processes: Metal Injection Molding

The metal injection molding (MIM) process is an efficient method for the high volume production of complex-shaped components from powders for high performance applications. Three systems, pure copper, Fe-12wt%Cu and heavy alloy parts from W-8%Ni-2%Cu powder mix were fabricated by metal injection molding. The soluble part of the binder was removed by organic solvent de-binding in n-heptane. The solvent de-binded specimens were used to study thermal de-binding of each system using evolved gas analysis technique. The thermo-gravimetric technique coupled with infrared and mass spectrometry provides sufficient knowledge to understand the degradation and reaction mechanisms during thermal de-binding.Thermo-physical data, on which temperature field calculation is strongly dependent, were also measured with best of available resources in AIT (Austrian Institute of Technology) laboratory using DSC, TGA-FTIR-MS, DIL and LFA instruments. Then finite element models were formulated by embedded kinetics model and thermo-physical data of the system. The formulated FE model described the material behavior during the thermal de-binding and sintering.