In-situ synthesis of TiC/SiC/Ti3SiC2 composite coatings by spark plasma sintering

Composite coatings consisting of TiC/SiC/Ti3SiC2 phases have been synthesized using spark plasma sintering (SPS) of Ti/SiC/C powder mixture on titanium substrate. The processing of composite coatings was achieved at 1300 degrees C and 1400 degrees C with a uniaxial pressure of 90 MPa and holding time of 8 min. Identification and quantification of the phases have been performed using x-ray diffraction (XRD). X-ray elemental maps obtained using EDS have been used to analyze the evolution of various phases and their distribution in the microstructure. A tentative mechanism for phase evolution based on exothermic reactions between various constituent powders has been proposed. Microhardness of the spark plasma sintered coatings was found to be similar to 3 times that of the Ti substrate resulting in similar to 100 times lower wear weight loss in ball-on-disc wear tests. (C) 2011 Elsevier B.V. All rights reserved.