Effect of deformation on densification and corrosion behavior of Al-ZrB2 composite

Abstract

In the present investigation, aluminium based metal matrix composites (MMCs) were produced through powder metallurgical route. Different composites were processed by adding different amount of ZrB2 (0, 2, 4 and 6 wt. %) at three aspect ratios of 0.35, 0.5, and 0.65, respectively. The powder mixture was compacted and pressureless sintered at 550 °C for 1 h in controlled atmosphere (argon gas). The relative density of the sintered preforms was found to be 90%, approximately. Sintered preforms are used as workpiece materials for deformation study at different temperatures in order to find the effect of temperature on the densification behaviour. Potentio-dynamic polarization studies were performed on the deformed preforms to find the effect of mechanical working. The corrosion rate was found to decrease with increase in deformation.

High Densification Level and Hardness Values of Additively Manufactured 316L Stainless Steel Fabricated by Fused Filament Fabrication

“…The trend of hardness variation follows that of the relative density shown in Table 1 and Figure 3, in which Tn=200°C yields the highest HV value (292 HV), followed by Tn=195°C (270 HV), and the lowest hardness is 160 HV that is attained at Tn=205°C. It is obvious that high void/defect contents lead to low hardness due to their collapse within the solid material under loading [18] and vice versa, as is the case for other materials subjected to sintering/melting and solidification processes [28][29][30][31]. The results of hardness values of sintered parts for Tn=195°C (relative density: 81.9%, hardness: 270 HV) and 200°C (relative density: 97.6%, hardness: 292 HV) are higher than those obtained in other studies of 316L SS fabricated by FFF AM and conventional PM and MIM processes reported in literature, ~100 -175 HV [3,[6][7][8][9][10], which can be attributed to the high volume fraction of metal powder (metal loading) of 87.5 wt.% used in this study compared to 50 -80 wt.% used in those studies.…”