There is provided a method for manufacturing a piston, including: a piston assembling step of forming a piston assembly by assembling a first piston part, a bonding member and a second piston part, wherein the first piston part has two or more bonding surfaces separate from each other and extending in a circumferential direction, and the second piston part has two or more bonding surfaces separate from each other and extending in the circumferential direction; a piston diffusion brazing step of diffusion brazing the first piston part, the bonding member and the second piston part under an open atmosphere by heating the formed piston assembly; and a piston cooling step of cooling a piston unit formed by diffusion brazing the first piston part, the bonding member and the second piston part. The piston diffusion brazing step is performed in a piston manufacturing device which includes a partially opened heating zone, a heater for providing heat into the heating zone, and a moving unit moved in one direction in the heating zone. In the piston diffusion brazing step, the piston assembly is heated while being moved at a predetermined speed through the heating zone in one direction by the moving unit.

A method for manufacturing a piston of an internal combustion engine from a piston upper part and a piston lower part may include producing at least the piston lower part as a forged steel part. A partial cross section of a cooling duct may be provided in the piston lower part. A closed supply inlet funnel may be forged within the piston lower part. The closed supply inlet funnel may be bored into the piston lower part from the cooling duct. A borehole may be introduced into the piston lower part obliquely to a piston axis. The piston lower part and the piston upper part may be welded to one another.

A composite engine component comprises a body having an outer circumferential surface and an inner circumferential surface. The body of the engine component is of unitary, integral, one-piece construction and comprises a radially inner section and a radially outer section having different material compositions. The radially inner section and the radially outer section of the body are welded together using a magnetic pulse welding process in which a metallurgical bond is formed along a bonding interface between the inner and outer sections of the body.

A valve for a valve device may include a valve stem, which in an axial direction relative to a valve stem axis merges into a valve disc projecting from the valve stem radially. A valve cap may be included composed of a metal. The valve cap may be attached to an axial end portion of the valve stem facing away from the valve disc. The valve cap may cover a face end of the valve stem facing away from the valve disc and may envelope the axial end portion of the valve stem at least partially.

A piston including at least one insert disposed between an inner surface of a ring belt and undercrown surface, and/or between the inner surface of the ring belt and a pin boss, to provide reinforcement to the ring belt is provided. The insert reduces thermal and mechanical distortion of the ring belt, and thus increases the piston ring performance, reduces blow-by, and ultimately improves engine emissions. The insert is formed by an additive machining process, such as direct depositing, laser cladding, laser sintering, arc welding, additive welding, plasma transferred arc spraying, plasma welding, arc welding, selective laser sintering, and high velocity oxygen fuel spraying, plasma spraying. According to one embodiment, an intermediate piece is mechanically attached to the piston, and the insert is applied to the intermediate piece, to provide additional reinforcement.

A method of making an engine system component is disclosed. The method may include loading a first metal-based material and a second metal-based material into an extrusion chamber. The first metal-based material may concentrically surround the second metal-based material, and the first metal-based material may have at least one of a thermal property and a wear resistance different than the second metal-based material. The method may additionally include forming an extrudate by simultaneously passing the first metal-based material and the second metal-based material through a die. The first metal-based material of the extrudate may be metallurgically bonded to the second metal-based material of the extrudate. The method may also include forging the extrudate.

A piston for an internal combustion engine includes a compound piston body having a crown piece joined to a skirt piece by a circumferential weld. The skirt piece is formed of a lower temperature-capable steel such as a low alloy steel, and the crown piece is formed of a higher temperature-capable steel having a martensitic microstructure and containing about 10% wt. or greater of chromium. Related methodology for making a piston is also disclosed.

A method of constructing a piston, piston formed thereby, and piston body portions are provided. The method includes providing an upper crown portion at least one annular upper rib depending from the upper combustion wall to a free end having a tapered peak. The method further includes providing a lower crown portion having at least one annular lower rib extending to a free end having a tapered peak. Then, moving the upper crown portion and the lower crown portion toward one another and initiating contact between the upper crown portion and the lower crown portion at their respective tapered peaks. Then, continuing moving the upper crown and the lower crown further toward one another after making initial contact at their respective tapered peaks and forming a friction weld joint between the free ends of the at least one upper rib and the at least one lower rib free end.

A piston capable of withstanding high temperatures and extreme conditions of a combustion chamber of an internal combustion engine and manufactured with reduced costs is provided. The method of manufacturing the piston includes casting or forging the bulk of the piston as a single-piece with an open cooling gallery from an economical first material, such as steel, cast iron, or aluminum. The method further includes forming a portion of a combustion bowl surface, which is a small area of the piston directly exposed to the combustion chamber, from a second material by additive machining. The second material has a higher thermal conductivity and higher resistance to oxidation, erosion, and oil coking, compared to the first material. The additive machining process is efficient and creates little waste, which further reduces production costs.

A hybrid induction welded piston including an upper piston part welded to a lower piston part is provided. The piston is produced by induction heating the upper piston part and the lower piston part, and bringing the parts together to a part growth compensated position. The method then includes rotating the upper piston part 17 to 34 degrees clockwise and then 17 to 34 degrees counterclockwise. In addition to controlling the axial position and degree of rotation, the force applied to the piston parts is controlled so that preferably no flash is formed in a narrow cooling chamber of the piston. During the rotating steps, the pressure gradually increases to a maximum level which occurs while the upper piston part is rotating in the second direction. The piston includes a homogenous metallurgical bond across the weld and no indentation on the outer surface at the weld prior to machining.