1. Field of the Invention
The present invention relates to a silicide joint and a method for manufacturing the silicide joint (hereinafter also referred to simply as “joint” and “method”) and, more particularly, to a silicide joint that may suitably be used as a high-temperature-resistant electrode material for heaters and a method for manufacturing the silicide joint.
2. Description of the Related Art
Silicon carbide (SiC) and nickel (Ni) are generally known to join to each other ohmically (with negligible contact resistance) under particular conditions. Furthermore, silicon and nickel form a nickel silicide at high temperature (see, for example, Japanese Unexamined Patent Application Publications No. 2004-128493 and No. 2005-150752).
Silicon carbide is useful as a material for high-temperature-resistant products, such as resistant electrodes for heaters. For example, Japanese Unexamined Patent Application Publication No. 2006-156043 discloses a joint structure that includes an electrode connected to a sintered silicon carbide heater at one end, and a spiral feed-terminal screwed into the other end of the electrode, wherein the electrode is formed of sintered silicon carbide.
However, when silicon carbide is used as an electrode material for heaters, the difference in thermal expansion coefficient between silicon carbide and nickel or nickel silicide often causes a failure at the interface between silicon carbide and nickel or nickel silicide during a heating process. More specifically, as illustrated in FIG. 4, in a common electrode joint that includes a silicon carbide plate 12 fixed between metal plates 11, such as nickel plates, with a metal bolt 13 and a metal nut 14, as the temperature increases, the difference in thermal expansion coefficient between the metal bolt 13 and the metal nut 14, and the silicon carbide plate 12 may result in a gap between the metal plates 11 and the silicon carbide plate 12 or in an outwardly warped metal plate 11. This may result in a longitudinal or transverse crack, finally causing a fracture. Hence, silicon carbide is difficult to use as an electrode material.