Abstract: Sintering method which comprises two principal stages, which are a first stage wherein green compacts are sintered in a regular manner, and a second stage which immediately follows the first stage and wherein sintered compacts are held for a set time at a temperature which is elevated but is below sintering temperature and in carburizing gas, thereby diffusing required component into the compacts, for example carbon in the case of ferro-carbide compacts for use as sliding elements. Also according to the invention a sintering box may have formed therein holes of set size and distribution density thereby to permit efficient removal of lubricant if initially added to compacts.

Abstract: A method of making a metal casting composed of a steel plate and aluminum material interlocked with the steel plate. A plurality of teeth are formed on at least one of the opposed surfaces of the steel plate by raising up a skin of the plate from the same, the teeth providing primary interstices, each of which extends from the steel plate and has at least one face with a number of flaws formed during the formation of the teeth and providing substantially irregular interstices. The casting is then formed by pouring aluminum material in the molten state onto the steel plate surface so that the molten aluminum material penetrates into the primary and irregular interstices, thereby to provide a firm interlocking between the steel plate and the aluminum material upon solidification thereof.

Abstract: A metal casting made of a steel plate and an aluminum material mechanically interlocked with the steel plate. The metal casting has a resistance to wear, impact and/or elevated temperature, or has other required or desired characteristics such as good heat conductivity. In order to increase the bonding strength or shear strength, the steel plate is formed with a plurality of teeth each raised up from the steel plate and having a number of surface irregularities and the molten aluminum material penetrates into the primary interstices defined by the spaces between the teeth and the irregular interstices defined by the surface irregularities on each of the teeth.