Preparation of Mullite–TiC–TiN Materials by a Spark Plasma Method with High Compaction Loading and Their Properties

Abstract

The phase composition of synthesized TiC and TiN materials and also the properties of mullite–TiC–TiN specimens with a different ratio of TiC and TiN, sintered by a spark plasma method in the range 1200 – 1600°C with a compaction load of 75 MPa are studied. Specimens with a different ratio of TiC and TiN are characterized by intense mullitization in the range from 1200 to 1600°C. an increase in TiC concentration, and correspondingly a reduction in TiN concentration in sintered powder mixtures facilitates formation at 1500°C of a densely sintered crystallized structure consisting of numerous mullite crystals, TiC and partly TiN, formed from melts. In the range 1400 – 1600°C the relative density and linear shrinkage of specimens gradually increases with a reduction in open porosity, but specimen elasticity modulus, Vickers hardness, and ultimate strength in compression increase.