Synthesis of titanium carbide powder by carbothermic reduction method B. Shahbahrami* 1 , M. Hakami 1 , H. Bastami 2 , E. Nadi-Mobarakeh 1 and M. Malekmohammadi 1 Carbothermic reduction method is an economical method for producing titanium carbide powder. In the present work, this method was used to produce titanium carbide powder using commercial raw materials. The starting materials were TiO 2 and petroleum coke, which were mixed and milled, sieved and then placed in an electrical resistance furnace (Acheson furnace). The reduction was carried out between 25 and 30 V and the current of 1800–2000 A. When the raw materials molar composition ratio was TiO 2 /C51:0?54, the best result was obtained. The samples were characterised by XRD, AAS and PSA techniques. Keywords: Titanium carbide, Synthesis, Carbothermic, Reduction Introduction Titanium carbide is a very attractive ceramic material because of its high melting point, low density, extreme hardness and strength, excellent wear, low friction coef- ficient, high thermal conductivity, high thermal shock resistance, high electrical conductivity, high chemical stability, capacity to deform plastically at high tempera- ture in a manner similar to FCC metals and high solvency for other carbides. 1 Therefore, titanium carbide can be used in cutting tools, grinding wheels, wear resistant coatings, high temperature heat exchangers, magnetic recording heads, turbine engine seals and bullet proof vests. 2 Methods that have been used to synthesise TiC powders can be classified into three categories: 3–5 (i) the direct carbonisation of titanium metal or titanium hydride, or combustion synthesis of TiC (ii) the gaseous pyrolysis of titanium halide, such as TiCl 4 , in a carbon containing atmosphere (iii) the carbothermal reduction of TiO 2 with carbon in controlled atmospheres high temperatures. The most widely used process for TiC production is carbothermal reduction of titanium dioxide (TiO 2 ) in the presence of carbon. Carbothermal reduction produces large amounts of powder, and makes use of inexpensive precursor materials. 1–3 The carbothermal reaction of synthesised TiC is as follows 1,2 TiO 2 z3C?TiCz2CO (g) (1) The reaction is highly endothermic and proceeds above 1298uC. In this work, formation of TiC particle during carbothermal reduction of TiO 2 is presented. Experimental The used materials are TiO 2 and petroleum coke. Chemical analysis of these materials is given in Table 1. The mixed powders with various composition ratios of raw materials were prepared. The mixing was made in a ball mill for 2 h and heated in an electrical resistance furnace. The furnace was made of mild steel with a water cooled copper jacket. Current was supplied to the graphite heating element through two terminal blocks. The heating element was machined from electrical arc furnace grade graphite electrode to 1 cm diameter and 40 cm length. Before the furnace was charged, the heating element was carefully placed between the two terminal blocks. The power supply to the furnace was drawn from a high current (2000 A and 30 V) single phase transformer. The variations of voltage and current values in the furnace were recorded as a function of time during the experiment. The current was increased to initiate the reduction process. As the reduction proceeded, the upper surface of the charge was broken at several locations to load extra amounts of few and recycled charge in known quantities. Then, the reaction was made and the furnace was allowed to cool overnight. The product was broken with a pneumatic hammer to recover fused titanium carbide chunks and powder. The chunk and the powder of titanium carbide were crushed in ball mills. The powder products were characterised by X-ray diffractometry (XRD), particle size analysis (PSA) and atomic absorption spectroscopy (AAS) techniques. Results and discussion The analysis of titanium carbide powder in different experiments was carried out. The chemical composition of products indicates the strong influence of charge stoichiometry (TiO 2 /C) on the products quality. The titanium dioxide content of the charges was kept at one 1 Islamic Azad University of Saveh, Saveh, Iran 2 Faculty of Engineering, Tarbiat Modares University, Tehran, Iran *Corresponding author, email behmut@yahoo.com ß W. S. Maney & Son Ltd. 2010 Received 26 January 2009; accepted 1 May 2009 DOI 10.1179/143307510X12599329343240 Materials Research Innovations 2010 VOL 14 NO 1 87