Densification and microstructures of hybrid sintering of titanium alloy

Abstract

Powder metallurgy has gained relevance particularly in processing complex components widely used in extreme service environments. With the huge success of powder metallurgy and rising technological demands came the need to fabricate larger components for industrial applications. Hybrid sintering (HSPS) has become a viable route to consolidate large and fully dense components owing to its unique heating system. The hybrid technique incorporates a combined system of spark plasma sintering (SPS) and hot pressing (HP) as a means of providing even heat distribution within the regime of the components. In this work, Ti64 alloy was produced using HSPS and SPS with a view to comparing the resulting bulk composites in each case. Uniformity was maintained in the sample diameter and sintering parameters were also kept constant in both cases for effective comparison purposes. The samples (60 mm) were fabricated and the resulting mechanical properties and microstructures of HSPSed and SPSed composite were studied. Results showed that HSPSed sample attained a densification of 98.9%, with Vickers micro-indentation hardness of 387 HV0.1, as compared with SPS-sample with densification of 97.9% and micro-hardness value of 378 HV0.1.