Life Science Journal 2013;10(8s) http://www.lifesciencesite.com http://www.lifesciencesite.com lifesciencej@gmail.com 336 Feasibility Study of Metallic Reductant Element Replacement by Mechanical Activation Process in ZrB 2 -ZrC Composite Synthesis from Raw Oxide Materials by SHS F. Adibpur 1 , M. Zakeri 2 , S.A. Tayebifard 3 * 1 Msc. Student of Nano-Materials & Nano-Technology Dept., MERC 2 Associate professor of Ceramic Dept., MERC 3 Associate professor of Semi-Conductor Dept., MERC * Materials & Energy Research Center a_tayebifard@yahoo.com Abstract: Because of many advantages of self-propagating high-temperature synthesis, this method is used increasingly for advanced compounds and composite materials production. ZrB 2 -ZrC composite has unique characteristics, so its synthesis with the least undesirable phases is an important problem for producing this composite. In this research, synthesis of this composite by metallic element as a reductant agent by SHS is done successfully, but elimination of undesirable compounds are costly and difficult. In order to prevent creating these compounds, replacement of metallic element by MASHS process, thermodynamically and practically points of view were studied. According to used mechanical activation conditions, synthesis of desirable composite was not occurred. For this process replacement, the initiating activation energy subject was discussed for achieved results. [F. Adibpur, M. Zakeri, S.A. Tayebifard. Feasibility Study of Metallic Reductant Element Replacement byMechanical Activation Process in ZrB 2 -ZrC Composite Synthesis from Raw Oxide Materials by SHS. Life Sci J 2013;10(8s): 336-341] (ISSN:1097-8135). http://www.lifesciencesite.com . 53 Keywords: SHS, Composite, ZrB 2 , ZrC, Mechanical activation 1. Introduction ZrB 2 -ZrC composite has unique properties such as high melting point, high strength and hardness, good toughness, low evaporation rate, chemical stability and good electrical and heat conductivity, so because of them, this composite is candidate as a constructional component for producing high temperature, erosive and corrosive environments resistance compounds [1,2]. Other used processes for preparing this composite is hot pressing (HP), spark plasma sintering (SPS), reactive hot pressing (RHP) and pressureless sintering (PS) [1]. Foundation of SHS process is based on exothermic reactions which after starting the reaction by sufficient energy, it continues spontaneously to consume reactants for producing of products. Amounts of produced heat are important, because next raw materials need to it for starting their reaction. This heat leads in combustion temperature [3]. The most important SHS process advantage is using of it for producing UHTC 1 materials. Other advantages of this process are high energy efficiency, producing pure products, suitable for single phase or composite compounds synthesis and simultaneously densification of them. Recently this process is 1 Ultra High Temperature Ceramics modified practically by mechanical (used for this research), chemical, preheated and electromagnetism activation [4]. According to these characteristics for SHS process and our own accord composite, it should be expected that ceramics which is prepared by ZrB 2 and ZrC and mentioned process have an excellent potentials for preparing heat resistance structures. For this purpose, preparing ZrB 2 -ZrC composites with fine structure and without impurities and undesirable phases are very important [5]. For initiating of some SHS reactions, chemical oven is used as producers of extreme needed heat. These ovens selected in such way that before starting the main reaction in furnace or reaction chamber, materials of oven react and produce sufficient heat for starting the main reaction and then it will be continued by itself [6]. 1. Scope In synthesis of ZrB 2 -ZrC composite by SHS process and Magnesium as a reductant and heat preparatory agent, undesirable phases produced by this metal compounds are unavoidable; so, this research is aimed to prevent producing them by