Sintered ceramic electric heater with improved thermal shock resistance
    8.
    发明授权
    Sintered ceramic electric heater with improved thermal shock resistance 失效
    烧结陶瓷电加热器具有改善的耐热冲击性

    公开(公告)号:US4633064A

    公开(公告)日:1986-12-30

    申请号:US739474

    申请日:1985-05-30

    摘要: A sintered ceramic heater, particularly a heater for a glow plug of a diesel engine, includes a sintered ceramic heater, which generates heat upon receiving an electric current, supported by an electrically insulating sintered ceramic body. The heater element includes a U-shaped cross-section outer portion integrally sintered with and covering a central portion. Each portion is formed of a sintered ceramic body of a mixture of electrically conductive ceramic powder having an average diameter of not more than 2 .mu.m and selected from the group consisting of MoSi.sub.2, WSi.sub.2, TiB.sub.2 and TiC, and 35-75 mol % of electrically insulating ceramic powder, e.g., Si.sub.3 N.sub.4. The central and outer portions have the same composition. However, in the central portion the average particle diameter of the conductive ceramic powder is equal to or larger than that of the insulating ceramic powder, whereas in the outer portion the average particle diameter of the conductive ceramic powder is not more than half that of the insulating ceramic powder. The specific resistance of the central portion is not less than 1.7 times as large as that of the outer portion so that the heat is generated by current flow through the outer portion of the ceramic heater.

    摘要翻译: 一种烧结陶瓷加热器,特别是用于柴油发动机的电热塞的加热器,包括烧结陶瓷加热器,其在接收电流时产生热量,由电绝缘的烧结陶瓷体支撑。 加热器元件包括与中心部分整体烧结并覆盖中心部分的U形横截面外部。 每个部分由平均直径不大于2μm并且选自MoSi 2,WSi 2,TiB 2和TiC的导电陶瓷粉末的混合物的烧结陶瓷体和35-75mol%的 电绝缘陶瓷粉末,例如Si3N4。 中部和外部具有相同的组成。 然而,在中心部分,导电陶瓷粉末的平均粒径等于或大于绝缘陶瓷粉末的平均粒径,而在外部,导电陶瓷粉末的平均粒径不大于绝缘陶瓷粉末的一半 绝缘陶瓷粉末。 中心部分的电阻率不小于外部电阻的1.7倍,因此通过陶瓷加热器的外部部分的电流产生热量。