Effect of chemical vapor deposition process parameters on the growth aspects of titanium carbide whiskers

Abstract

The advent of SiC-whisker-reinforced ceramic cutting tools in the past few years has had a dramatic impact in the machining of hard abrasive superalloys and other difficult-to-machine metals. These advances have led to investigation of alternative whisker materials in terms of chemical compatibility with the matrix, and improved mechanical properties of the composite, which are quality, purity, morphology and aspect ratio of whiskers. These aspects are closely linked with the process of making whiskers. Chemical vapor depoaition (CVD) is a versatile technique for controlling the critical properties of whiskers. In this paper, we discuss the effects of various CVD process parameters, such as reactive gas concentrations, total flow, temperature and reactor configuration on the growth morphology, yield and purity of titanium carbide whiskers, which are deposited in a conventional atmospheric pressure CVD reactor. The effect of nickel catalyst on the size and yield of whiskers, and the role of the limiting reactant species, are also briefly discussed. It is suggested that the growth of high quality whiskers of TiC can be achieved by a due consideration of process parameters and reactor configuration.