Production of Silicon Carbide Pieces by Immersion of Silicon Preforms in Carbonaceous Powders

Abstract

In this work a novel method for production of silicon carbide (SiC) pieces, which involves the heating of silicon (Si) preforms immersed in graphite powder is presented. Such preforms were obtained via low‐pressure injection molding (LPIM), although any other conformation route can be used. The process can be carried out at modest temperatures and gradients in standard furnaces used for processing other ceramics. These features make this process a simpler and cheaper alternative, when compared with other methods of SiC fabrication. The variables affecting the process have been identified, and an optimum‐heating ramp has been established. Under these conditions, the obtained SiC products show no remnant‐free Si, and their mechanical behavior allows their use in several less‐demanding SiC applications, for which expensive high‐performance SiC products are unaffordable. In the proposed chain of reactions, CO(g) is responsible for the carburization of the pieces. All phases present are identified, and their distribution is explained by means of competitive reactions. In our opinion, this novel method can be extended to an industrial scale because it is simple and involves cheap raw materials.

Synthesis and Characteristics of Cubic Silicon Carbide Nanospheres with Smooth Surfaces

“…31 At the synthesis temperature of 1150 C, 3C-SiC cannot grow from the reaction between silicon and activated carbon directly. 3 According to the report by Niu et al, 32 33 the action of ZnS is to support more activated Si and SiO 2 . The reactions are shown in the following: 32 33 2ZnS…”

“…3 Actually, we have tried to fabricate 3C-SiC free of ZnS powder under the same conditions and found that no 3C-SiC nanospheres could be formed on the Si wafer. This suggests that ZnS powder play a key role in the growth of the 3C-SiC nanospheres.…”

“…These outstanding physical and chemical properties make SiC a promising candidate in devices designed to operate at high frequency, high voltage, high power, and high temperature as well as in a harsh environment. [1][2][3][4] Nanosized materials that possess unique properties have opened up a new research area and many novel applications. In the case of SiC, much attention has been paid to the synthesis techniques and properties of nanostructured SiC.…”

Syntheses and Growth Mechanisms of 3<I>C</I>-SiC Nanostructures from Carbon and Silicon Powders

“…1 The chamber has not been vacuumized before being heated, and the Ar gas used in present study is 99% pure. These lead to a trace amount of Copyright: American Scientific Publishers residual oxygen present in the growth chamber.…”