Phase Analyses of a TtPt Alloy Synthesized by Spark Plasma Sintering
A Ti-50at%Pt alloy synthesized using the spark plasma sintering (SPS) technique has been characterized for phases’ identification. TiPt alloys have potential use as high temperature shape memory alloys(HTSMAs). Test specimens were prepared at SPS temperature of 1300°C. Sintering pressure and time were varied. The microstructural features of the specimens were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electron microscope used was equipped with an EDS detector, that, together with the XRD, were used for both the identification and analyses of the phases in the starting materials and the sintered alloys. High temperature XRD (800 -1300°C) as well as ambient temperature XRD analyses were done on the starting mechanically alloyed powders. All the samples tested at elevated temperatures were subsequently tested at room temperature after cooling. XRD analyses of the sintered samples were all done at room temperature. Analyses of the XRD results revealed new distinct phases from a temperature of 1000°C. A comparison of the room temperature XRD results for alloy powders and that of the sintered alloys was made. The following phases have been identified and studied TiPt B2, TiPt B19, Pt3Ti, Ti3Pt and Pt5Ti3. SPS pressure and sintering time did not show much effect on the phases detected. The alloy composition was found to be very inhomogeneous.
Yi Tan and Dongying Ju
H. K. Chikwanda et al., "Phase Analyses of a TtPt Alloy Synthesized by Spark Plasma Sintering", Materials Science Forum, Vols. 675-677, pp. 1143-1146, 2011