The baseball spike is used carbon steel mainly. But, the spike was worn down with soil.
Our developed baseball spike is designed to connect cemented carbide and carbon steel by resistance welding. However, there is a problem of connecting technology of the ceramics and the metal, because of the temperature stress destruction which originates in the thermal expansion difference of the ceramics and the metal. It was necessary to develop the connecting technology in order to control this effectively. The cemented carbide tip and the shank are bonded by optimum welding condition, and so the bead is formed to the boundary section.
The bottom of cemented carbide tip contacts with a groove of shank surface in the point, and thus, electric current per unit time flows more and welding efficiency improves.
Coefficient of thermal conductivity of cemented carbide is large in comparison with carbon steel. With the heat energy when welding, the part of cemented carbide tip melts, then a solid solution layer is formed around cemented carbide tip. The hardness of this part shows the value between hardness of cemented carbide and carbon steel. In other words it becomes functionally graded spike. Finally, we could develop the baseball spike which is superior in abrasion, and with low cost.