Effect of Temperature on Densification, Microstructural Evolution and Mechanical Properties of Ti-5Al-1Mo Developed via Spark Plasma Sintering

Abstract

Abstract Titanium alloys are ideally suited for advanced aerospace structures and industrial applications because of the combination of high strength, low density, good toughness, stiffness, and good corrosion resistance at cryogenic to elevated temperatures. This paper investigates the effect of temperature on alloy densification, microstructure evolution and mechanical properties of Ti-5Al-1Mo processed by Spark Plasma Sintering (SPS). Ti, Al, Mo elemental powders with 94, 5 and 1 wt.% respectively were mixed thoroughly for 8 hrs to attain homogeneity. The mixed powders were consolidated at sintering temperature of 800°C, 1000 °C, 1100 °C, pressure of 50 MPa, holding time of 10 min, and sintering rate of 100 °C/min. The compacted samples were characterised using scanning electron microscopy (SEM), equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffractometry techniques. Compacts hardness was also investigated using Vickers micro-hardness tester. Almost fully densified compacts were obtained for samples sintered at 1000 °C and 1100 °C, the microstructures show that the sintered compacts are chemically homogeneous with the Al fully diffused into the CP-Ti matrix. The microhardness increases with increasing temperature with the maximum value being 290.35 HV.