Effect of green density and ZnSt debinding process on properties of PM materials produced with premixed powder

Abstract In this study, the effect of compression pressure on the properties of powder metallurgy materials produced with premixed commercial Alumix-123 powder without lubricant and with 1.5 wt. % zinc stearate lubricant was investigated. Differential scanning calorimetry and thermal gravimetric analyses were performed to determine the thermal stability of the lubricant. The microstructures of the samples were characterized by optical microscopy, scanning electron microscopy, and X-ray diffraction analyses. A parabolic increase in the densities of the sintered lubricant and unlubricated samples was determined with increasing compression pressure. However, it was observed that the densities of the lubricant samples compressed and sintered at high pressure reduced partially compared to the green density. The Zn remaining from the lubricant between the premixed Cu and Al particles formed Al-rich partial liquid phases and ZnAl intermetallic phases. Analysis results showed that with increasing compression pressure and green density, the dissolution rate of the lubricant decreased.