Effects of the Decomposition Residue of Compound Additive on Resintering Behavior

Various types of compounds were tested with the aspects of decomposition and formation of residue in a or 7H+93 atmosphere. The evaporation temperature range of each compound was determined from thermogravimetric curve. Decomposition of dicarbon amide, stearic acid, acrowax and zinc stearate was studied by thermogravimetry in or in 7H+93 atmosphere. All compounds were decomposed in atmosphere at lower than 40, but the residue, ZnO remained for zinc stearate. ZnO did not decompose in atmosphere up to 130, but reduced into Zn metal and disappeared in the temperature range of to 120 in 7H+93 atmosphere. The effect of residue, which trapped in closed pores of sintered pellet, on the thermal stability was studied using the resintering test at 1 in 7H+93 atmosphere. In the case of oxidative sintered pellet with admixing zinc stearate, the cavity formation accompanied with a density drop after resintering is due to the pressure of the Zn gases trapped in the isolated pores