Investigation of moldability parameters of powder injection molded Al-Fe-V-Si composites by adding alumina

In this study, the Al-8.5 Fe-1.3V-1.7Si (8009 Al) mixed powders have been molded by powder injection molding (PIM) method. Besides, 5%, 10% and 15% alumina has been added to this mixture. 65% PEG8000 (polyethylene glycol) + 30%PP (polypropylene) + 5%SA (steatite acid) in weight has been used as the binder. The rheology tests have shown that, the optimum powder / binder ratio is 63%/37% in volume for 0% and 5% added alumina powders, whereas; 62%/38% and 61%/39% are the optimum values for the 10% and 15% alumina powders added to mixtures respectively.The feedstocks have been prepared using these ratios, and then the PIM has been applied. The molded samples have been applied to remove thermal binders and solvents (pre-sintering).The sintering has been applied at 640°C. A mixed gas (5% hydrogen+95% argon) has been used as the sintering atmosphere. But, the sintering process could not have been achieved successfully due to occurring oxides on the surfaces of the specimens, therefore densification has not been observed. Hence, carnauba wax has been preferred instead of the PEG8000 as the binder thus; the new samples have been prepared. 50% carnauba wax+ 45%PP + 5%SA has been considered as the new binder. Debinding has been applied under gas + vacuum conditions then, the sintering has been conducted using the same conditions with the previous experiments. Strength of the new specimens showed a slight increase considering the samples by the PEG8000 binder. Even though there is an increase on the strength, SEM analysis showed that there has not been any sintering between the powders which has been molded by the carnauba wax binder.