Growth inhibiting during ultra-high temperature sintering of injection moulded 17-4 PH stainless steel through the dispersion of ZrO2 particle as a thermal stabiliser

ABSTRACT The present work deals with the metal injection moulding and ultra-high temperature sintering of 17-4 PH powder. Purposefully, 5 mass% ZrO2 particles were dispersed by applying high shear stress during feedstock preparation. Uniformly distributed particles effectively hindered the powder boundary migration and limited their growth during ultra-high sintering temperatures. The achieved thermal stability provided a proper condition for reducing the final porosity to 3% and significantly improved the ultimate strength to 1070 MPa after sintering at 1380°C. Also, the ZrO2 particles acted as facilitators of sliding between solid powders and substantially reduced the required pressure for injecting to 700 Bar. Through introducing such a new approach in the field of powder injection moulding by ZrO2 particles, the amount of anisotropic shrinkage was reduced to 2%.