Abstract: In a composite material of metal and ceramic, the excellent properties of metal and ceramic are combined, so that, when the composite material is flame sprayed, a flame sprayed coating having good mechanical strength and heat- corrosion- and wear-resistance can be obtained. Conventional composite material, in which metal and ceramic are merely mixed or mechanically bonded with one another, cannot provide a plasma sprayed coating having a high bonding strength to the substrate. The present invention improves the plasma spraying composite material by means of a chemical bond between the metal and ceramic parts. The chemical bond may be a compound-or solid solution formation between these parts. The core of the composite material is ZrO.sub.2 and the coating is a metal, metallic compound or combination thereof.

Abstract: A method and an apparatus for clearing burrs from products fabricated from metal stock. The burr of a product is used as one electrode, and another electrode is formed by extending an electrode material along, and apart from, the burr. A voltage is applied across the electrode to generate an arc between them. In the meanwhile, a magnetic field having a magnetic flux flow crossing the arc is formed to drive the arc along the burr by an electromagnetic force whereby the burr is melted and removed from the product.