Verfahren zur Herstellung von Widerstandsheizelementen

1,128,028. Resistance heating elements. BASIC Inc. 4 Nov., 1965 [6 Nov., 1964], No. 46809/65. Heading H5H. [Also in Divisions B5 and C7] The electrical resistance of an explosivelycompacted silicon carbide heater element is modified by the addition of 2À5-5 v/o of silicon, BN, MoSi 2 , B 4 C or TiC, or a mixture of 86 v/o ZrBr 2 -12 v/o MoSi 2 -2 v/o BN. Silicon carbide particles and the powdered additives are explosively compacted to give an integrally formed element having terminal "cold zones" and an intermediate "hot zone", the "cold zones" comprising 60 v/o silicon carbide and 40 v/o additive and the "hot zone" comprising 97 v/o silicon carbide and 3 v/o additive. The compacted element is sintered for 2-8 hours in vacuo, in a noble gas or a low molecular weight carbon-bearing gas atmosphere at 2500-2700‹ F., the final element having a density of 2À88-3À04 gm. c.c.-1.