Comparison of a commercial powder and a powder produced from Ti-6Al-4V chips and their effects on compacts sintered by the sinter-HIP method

Abstract

The present paper is related to the conversion of Ti-6Al-4V chips into powder and investigates the usability of the produced powder in powder metallurgy applications. In this regard, a disc-milling process was applied to Ti-6Al-4V chips and the obtained powder was subsequently compacted. The compacted samples were sintered by the sinter hot isostatic pressing (sinter-HIP) method at 1200°C under high vacuum, their mechanical properties and microstructure were investigated and compared with those of commercial powder compacts subjected to the same preparation processes. The results showed that the produced powder exhibits greater flowability and higher apparent density than the commercial powder. However, the sintered products prepared from the commercial powder exhibited a higher relative density, lower porosity, and, as a result, greater flexural strength compared with the sintered compacts prepared from the produced powder. In addition, transgranular fracture was greater in the sintered products of the commercial powder. The microstructural studies revealed that the sintered products made from both the commercial and the produced powders consisted of α- and β-phase but contained more α-phase. All of the examined properties were found to be substantially affected by the particle size of the powders.

Keywords

Ti-6Al-4V / chips / sinter hot isostatic pressing / flexural strength / porosity

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