Sintering comparison of NiCoCrAl-Ta powder processed by hot pressing and spark plasma

Hot pressing and spark plasma sintering were carried out to densify commercial alloy NiCoCrAl-Ta powder at temperatures ranging between 1173 and 1473 K in order to obtain a variety of microstructures. Full densification is achieved in a short time and the overall processing time not was exceeding 30 min via SPS process. Microstructural and porosity evaluation was investigated by using scanning electron microscopy and chemical analysis. Beta (β) and gamma (γ) phases were identified on sintered sample microstructure by XR-Diffraction. The set conditions are very promising from an energy-saving viewpoint; total powder consolidation was obtained per a decrease of 200 °C in the sintering temperature by using spark plasma sintering as compared with hot pressing process.

Spark plasma sintering (SPS) is an emerging investigation theme of current activated sintering and this presents advantages over conventional processes. In the present study we have processed NiCoCrAl-Ta powder by SPS. Specimens with a good compacting and homogeneous microstructures were obtained by SPS. Such microstructure refined represents a real advantage with respect to hot-pressing conventional processing by a decrease of 200 °C in the sintering temperature by using SPS.Figure optionsDownload as PowerPoint slideHighlights
► Spark plasma sintering (SPS) is an emerging investigation theme of current activated sintering.
► It has processed NiCoCrAl-Ta powder by using SPS.
► Specimens with a good compacting and homogeneous microstructures were obtained.
► A decrease of 200 °C in the sintering temperature has been obtained via SPS.