## 1 Introduction  
Silicon carbide (SiC) has excellent thermal conductivity, chemical inertness, and high value of the Young's modulus, strength, toughness, and optics properties [1; 2; 3; 4]. Thus, SiC was generally used in high temperature, high power, and high frequency as well as in harsh environments. The outstanding mechanical properties of SiC nanowhiskers (NWs) make it a promising candidate for the reinforcing phase in ceramic, metal, and polymer matrix composites. SiC NWs also show potential for fruitful applications in field emission displays, nanosensors, nanoscale electro-devices, and optoelectronic devices [1; 2; 3; 4]. To date, many methods [5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15] have been applied to prepare SiC whiskers or NWs, including the most common and commercial methods such as chemical vapor deposition from silanes, thermal decomposition of rice hulls, and thermal reduction of silicon oxides, in particular on silica and carbon solid mixtures [16]. Though they are industrial production processes, there are still some shortcomings such as the large amount of energy and time consumption, the small amount of whiskers in the whiskers/particle products, and a certain amount of residual Si and C particles and low-melting Fe-Si alloy or other low-melting alloys in the products; most of all, these low-melting particles are detrimental phases in high-temperature environments. To get high quality,a complicated post process is needed to get high quality nanow whiskers, since whiskers must be separated from the whiskers/particle and purified of the residual Si and C particles and low melting alloys in the products. These shortcomings cause the high production cost directly or indirectly [1]. Combustion synthesis (CS) is an easy, efficient, and low-cost method to obtain a wide variety of materials [1; 2; 17]. In comparison with the conventional synthesis methods of SiC whiskers, the CS process possesses significant advantages such as great energy efficiency, high purity of the products, and high production rate. It is well known that an empirical criterion typically adopted for determining the feasibility of CS is an adiabatic temperature exceeding 1800 K [18]. For combustion synthesized (CSed) pure SiC nanow whiskers (NWs), however, the CS process for the formation of pure SiC nanow whiskers (NWs) needs extra energy, due to a low adiabatic combustion temperature of the Si/C system (ca 54 1600-1700 K) [19; 20], In this case, introduction of nitrogen can be a feasible approach, since a strong exothermic reaction, 3 Si(s) + 2 N\({}_{2}\)(g) \(\rightarrow\) Si\({}_{3}\)N\({}_{4}\)(s) (calculated adiabatic temperature can reach above 4000 K [21; 22]), could be a smart way to assist the CS of SiC. Thus, it is crucial to study the fabrication of high purity SiC phase in the Si-C-N system. However, many factors can affect the growth of SiC NWs, therefore, control of the morphology of SiC to be one-dimensional (1D) nanostructure in a Si-C-N system is a key issue. Of particular interest is the catalyst, which plays a critical role in the growth of SiC NWs. However, the exact role of the catalyst in whisker growth, depending on the type of selected catalyst, is still unknown and it should be further clarified. Furthermore, not only the effect of the catalyst itself, but also the final status of the catalyst in NWs, in particular in their high temperature applications, should also be taken into account. We have previously reported the fabrication of CSed SiC NWs using titanium powder as a catalyst, but the yield of whiskers needs further optimization [1]. Herein, tungsten (W) was selected as the catalyst because of its high melting point, thus it is not harmful in high temperature structure materials. Moreover, W can react with C, N, or Si elements to form high melting points tungsten carbides, tungsten nitrides, or tungsten silicides, respectively, which is favorable for high temperature performance in structural materials.