1. Fields of the Invention
The present invention relates to a ceramic sinter having a high thermal expansion coefficient combinable with a general use metal such as stainless steel so as to constitute a composite body applicable under a high temperature circumstance
2. Description of Prior Art
Ceramics are being increasingly used in many field because of their excellent thermal and chemical properties such as heat resistance and corrosion resistance and replaced for metal material in some fields so that performance limits of machines are improved. However workability, toughness and thermal shock resistance of the ceramics are lower than those of metal material. To overcome these disadvantages, a composite body of ceramic and metal is proposed, in that, for the portion which requires a high heat resistance and a high corrosion resistance ceramics are employed and for the portion which requires a high toughness and a complex configuration metal materials are employed.
Japanese Patent Publication No. 60-29668, for example, discloses a composite body of a ferrite core and a ceramic supporting the same for a magnetic head, the ceramic essentially consists of TiO.sub.2, BaO, SiO.sub.2, Nb.sub.2 O.sub.5 and ZnO and has a thermal expansion coefficient of 6-12.times.10.sup.-6 /.degree.C. which agrees with that of the ferrite core.
Japanese Patent Publication No. 60-18621, for example, discloses a composite body of a cast iron and a ceramic bonded thereto for an internal combustion engine part, the ceramic essentially consists of partly stabilized zirconia and has a thermal expansion coefficient of 10.3.times.10.sup.-6 /.degree.C. which is substantially equivalent to that of cast iron.
However, until now no such ceramics having a thermal expansion coefficientof more than 13.times.10.sup.-6 .degree.C. and a high flexural strength required for structural components are disclosed that are used in combination with general use metals such as carbon steel, of which the thermal expansion coefficient is 13-14.times.10.sup.-6 /.degree.C., alloy steel, of which the thermal expansion coefficient is 8-20.times.10.sup.-6 /.degree.C., and stainless steel, of which the thermal expansion coefficient is 15-20.times.10.sup.-6 /.degree.C.