System for preventing decomposition of silicon carbide articles during sintering

A method for preventing, halting. retarding or reversing the decomposition of silicon carbide articles during high temperature sintering in a plasma furnace comprising:

• placing formed silicon carbide articles into a plasma furnace;
• injecting a plasma arc heated gas from at least one primary torch which is positioned near the top of said furnace in order to avoid the formation of cold pockets;
• sintering said silicon carbide articles in a plasma gas environment produced by said primary plasma torch;
• and
• expending the exhaust produced by said plasma gas through an exhaust outlet positioned near the bottom of said furnace in order to minimize the buoyant effects of the convected heat transfer resulting therefrom.

A method for preventing, halting, retarding or reversing the decomposition of silicon carbide articles during high temperature sintering in a plasma furnace comprising:

• placing formed silicon carbide articles into a plasma furnace;
• placing a sacrificial source of silicon carbide in said plasma furnace, said sacrificial source of silicon carbide beginning decomposition before the silicon carbide articles during sintering;
• and;
• sintering said silicon carbide articles in a plasma gas environment.

A furnace for the high temperature sintering of silicon carbide articles and for preventing, halting, retarding or reversing the decomposition of said silicon carbide articles during sintering, comprising:

• a sintering chamber;
• at least one covered crucible for containing said silicon carbide articles within said sintering chamber;
• a plasma gas inlet positioned near the top of said sintering chamber;
• and,
• an exhaust outlet positioned near the bottom of said sintering chamber.

A furnace for the high temperature sintering of silicon carbide articles and for preventing, halting, retarding or reversing the decomposition of said silicon carbide articles during sintering, comprising:

• a sintering chamber;
• at least one crucible for containing said silicon carbide articles within said sintering chamber;
• a plasma gas inlet positioned near the top of said sintering chamber;
• an exhaust outlet positioned near the bottom of said sintering chamber;
• and
• a sacrificial source of silicon carbide supported within said sintering chamber, wherein said sacrificial source of silicon carbide begins decomposition before the silicon carbide articles being sintered.