Self-propagating combustion synthesis and plasma spraying deposition of TiC-Fe powders

The synthesis of titanium carbide/iron composite from elemental powders by means of self-propagating reactions to be subsequently employed for plasma spray deposition is investigated. The combustion temperature and velocity of propagating front are found to decrease as the amount of iron in the starting mixture increased. In addition, the maximum value of the iron content in the initial mixture allowable for guaranteeing the self-propagating character of the combustion synthesis process is identified. Below this threshold, i.e. 60 wt.%, independently of the iron content, the final products resulted constituted by titanium carbide and iron, being the latter one found as a binder distributed around the carbide grains. In particular, a strong dependence of the grains size of the obtained titanium carbide on the iron content is observed. Once reduced in powder form, the obtained composite, specifically TiC-30 wt.% Fe. is subsequently used for thermal spraying coatings deposition. Adhesion performance, hardness and wear resistance tests results for the obtained coatings by vacuum plasma spraying are also reported. (C) 2003 Elsevier Science Ltd and Techna S.r.l. All rights reserved