Abstract: An apparatus for thermally spraying a coating on a workpiece includes a fluid flow control shroud having a shaped inner surface portion complimentary to a preselected surface of the workpiece. During the coating operation, a supply of pressurized gas is introduced between the inner surface of the shroud and the workpiece surface to exclude deflected coating particles, remove weakly or loosely bonded particles, and cool the workpiece.

Abstract: An aluminum piston for use in heavy duty internal combustion engines is disclosed, in which the grooves for receiving the piston rings are formed in stainless steel inserts fusion bonded directly to the aluminum without an intermediate metallic layer other than the resulting alloy of the steel and aluminum. The method of making such piston is described in which austenitic stainless steel powder deposited in an oversize groove in the aluminum piston is melted in situ by a laser beam to simultaneously form the stainless steel insert and alloy it with the aluminum to provide a fusion bond, the piston ring groove being subsequently formed in the stainless steel insert.

Abstract: An aluminum piston for use in heavy duty internal combustion engines is disclosed, in which the grooves for receiving the piston rings are formed in stainless steel inserts fusion bonded directly to the aluminum without an intermediate metallic layer other than the resulting alloy of the steel and aluminum. The method of making such piston is described in which austenitic stainless steel powder deposited in an oversize groove in the aluminum piston is melted in situ by a laser beam to simultaneously form the stainless steel insert and alloy it with the aluminum to provide a fusion bond, the piston ring groove being subsequently formed in the stainless steel insert.