Process for producing silicon carbide heating elements

DETAILED DESCRIPTION However, it has now been found that the influence obtained by nitrogen addition can be further improved and the electrical resistivity can be decreased by changing the nitrogen atmosphere in the secondary sintering for a pressurized nitrogen atmosphere.
Accordingly, the present invention relates to a process for producing a silicon carbide heating element comprising: adding boron or a boron compound in an amount corresponding to 0.
3 to 3.
0% by weight as boron and carbon or a carbon compound in an amount corresponding to 0.
1 to 6.
0% by weight as carbon to a SiC powder having the average particle size of 1.
0.
mu.
or less; blending and molding the mixture; carrying out primary sintering in vacuum or in an inert atmosphere, except nitrogen; and thereafter carrying out secondary sintering at from 1500.
degree.
to 2300.
degree.
C.
in a pressurized nitrogen atmosphere to produce a silicon carbide heating element having a density of at least 80% based on the theoretical density and an electrical resistivity of 1.
0 .
OMEGA.
-cm or less.