Statistical analysis of shrinkage variation for powder injection molding

A 2(4) factorial design was conducted to establish the effects of powder injection molding (PIM) parameters on the shrinkage properties of the widely used Fe-Ni powder system. Four process parameters were analyzed simultaneously: (i) the debinding method, i.e., solvent condensation versus vacuum; (ii) the sintering heating rate; (iii) the sintering hold temperature; and (iv) the sintering hold time. Dimensional measurements of the length, width and thickness of green and sintered rectangular tensile specimens were made. An analysis of variance, together with the F-test, were used to determine the statistical significance of each of the parameters on the length, width and thickness shrinkages.