Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5457990 | International Journal of Refractory Metals and Hard Materials | 2017 | 5 Pages |
Abstract
Fundamental aspects of reaction behavior and formation path in the Cr2O3-B2O3-Mg-C quaternary system have been studied to synthesize chromium boride-chromium carbide nanocomposite. In order to find the influence of simultaneous presence of magnesium and carbon on final products, various powder mixtures were chosen according to following reaction: B2O3 + Cr2O3 + (9 â x) Mg + x C. The value of x varied from 0 to 4. In the absence of carbon (x = 0), CrB2 was synthesize through mechanically induced self-propagating reaction (MSR). In the presence of 8 mol Mg and 1 mol C (x = 1), the dominant boride phase was CrB while no chromium carbide was detected. By increasing C content (x = 2), the magnesiothermic reduction occurred in MSR mode; whereas, the synthesis of Cr3C2 initiated after combustion reaction and completed gradually during milling for 6 h. Further increase in C amount (x = 3) resulted in formation of Mg3(BO3)2 as unwanted phases as well as CrB and Cr3C2. In the presence of 6 mol Mg and 4 mol (x = 4), no mechanical reaction was observed even after 8 h of milling. Optimum value of x for the formation of CrB-Cr3C2 nanocomposite was 2. Based on the morphological evolutions, it is evident that the mechanosynthesized powder is made up of nanometric particles.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Omid Torabi, Mohammad Hossein Golabgir, Hamid Tajizadegan, Amin Jamshidi,