Laser beam sintering of thin alumina coatings on metals

Abstract

This paper is focussed on introducing technology and results of a laser sintering process. Laser beam sintering of alumina coatings on metals was investigated as a part of a joint project carried out by the Fraunhofer IKTS Dresden and the Laserinstitut Mittelsachsen e.V. (Laser Institute of Middle Saxony, LIM). The IKTS team developed a method for deposing alumina powder on a metal surface by electrophoretic deposition. The powder layer was characterised by a grain size of about 200 nm and a high density. These properties enable a sintering temperature below the metal’s melting point. The LIM group developed a technology for sintering the powder layer by laser beam. The results achieved were very promising. The layer of a thickness of about 10 µm adhered well and had a low porosity and high hardness. Applications based on this technology are expected in several branches.