Relationship Between Microstructure and Tensile Properties of A Ti-6Al-4V Produced by Spark Plasma Sintering
Résumé
A prealloyed Ti-6Al-4V powder has been consolidated to near full density by Spark Plasma Sintering (SPS). Near-Net-Shape (NNS) tensile specimens have been obtained directly from the process for the same pressure and a temperature close to the β transus (Tβ). The influence on microstructure and tensile behavior of some sintering parameters, such as dwell time and the powder size distribution, has been studied. Longer dwell time seems to have no obvious effect on properties. The selection of granules size in the range of 50 to 100 μm did not lead to a significant strengthening due to Hall-Petch effect comparing to the powder distribution in the larger range of 40 to 400 μm.
The tensile behavior of the NNS specimens are promising as they are slightly higher (Yield Strength -σy, Ultimate Tensile Strength -UTS, Failure strain -ϵf) than to the ones coming from the other authors using SPS and other processes such as rolling and hot isostatic pressing (HIP). However, the control of the desired microstructure has to be improved and will be the concern of future research.