A steel piston with a bushing applied to pin bore surfaces by laser cladding or laser additive manufacturing is provided. The bushing is formed of metal, such as bronze, and metallurgically bonded to the steel of the piston. Thus, the bushing cannot fail by rotating relative to pin bore surfaces. The bushing has a porosity ranging from 0.05% to 5%, based on the total volume of the bushing, and a thickness ranging from 0.07 mm to 6 mm. Since the metal is applied directly to the steel by laser cladding or laser additive manufacturing, the overall size of the piston is reduced, compared to typical pistons with a separate steel backed bushing, and the possibility of bushing rotation is avoided. The bushing also provides scuffing resistance and increased unit load capacity of the pin bore.

A method of manufacturing an engine piston may include performing upper-body formation for forming an upper body as an upper portion of a piston body by pressing a powder-type sintered material, performing lower-body formation for forming a lower body as a lower portion of the piston body by pressing a powder-type sintered material, performing bonding for forming the piston body by providing a brazing material between the upper body and the lower body and brazing the upper body and the lower body to each other while sintering a sintered material, performing machining for removing pores from the surface of the piston body by machining the surface, and performing heat treatment for forming a passive film by performing at least one of nitriding heat treatment or oxidation heat treatment on the surface of the piston body.

A linerless engine block includes a polymer matrix composite having an internal surface that defines a bore. The polymer matrix composite has a first thermal conductivity at the internal surface of at least 5 W/m.Math. C. The linerless engine block also includes a first bond coating disposed on the internal surface within the bore, and a second wear-resistant coating disposed on the first bond coating within the bore such that the second wear-resistant coating is adhered to the polymer matrix composite by the first bond coating. A method of forming the linerless engine block is also described.

Methods and systems are provided for filling surface pores of a cylinder inner surface coating with one or more fill materials to provide desired material and performance properties. In one example, a cylinder for an engine includes an inner surface including a coating having a plurality of surface pores, at least a portion of the plurality of surface pores filled with one or more fill materials, the one or more fill materials configured to decrease friction, increase tribofilm formation, adjust heat transfer, decrease material deposit, and/or decrease run-in duration.

Methods and systems are provided for filling surface pores of a cylinder inner surface coating with one or more fill materials to provide desired material and performance properties. In one example, a cylinder for an engine includes an inner surface including a coating having a plurality of surface pores, at least a portion of the plurality of surface pores filled with one or more fill materials, the one or more fill materials configured to decrease friction, increase tribofilm formation, adjust heat transfer, decrease material deposit, and/or decrease run-in duration.

At least one coated valve seat region has at least one first layer and a second layer, the second layer is arranged on the first layer, and the first layer and the second layer are different. The first layer and the second layer are each formed by a local thermal deposition welding method. In the case of a cylinder head of an internal combustion engine, a valve seat region is formed by depositing a first layer on a substrate material of the valve seat by a laser deposition welding method in one method step and, in a subsequent method step, depositing a second layer on the first layer by a laser deposition welding method. The second layer contains a material which exerts a material hardening effect.

A method of manufacturing an engine piston may include performing upper-body formation for forming an upper body as an upper portion of a piston body by pressing a powder-type sintered material, performing lower-body formation for forming a lower body as a lower portion of the piston body by pressing a powder-type sintered material, performing bonding for forming the piston body by providing a brazing material between the upper body and the lower body and brazing the upper body and the lower body to each other while sintering a sintered material, performing machining for removing pores from the surface of the piston body by machining the surface, and performing heat treatment for forming a passive film by performing at least one of nitriding heat treatment or oxidation heat treatment on the surface of the piston body.

A vehicle internal combustion piston and method of construction thereof are provided. The piston includes piston body extending along a central longitudinal axis, having an upper combustion wall forming an upper combustion surface and an undercrown surface opposite the upper combustion surface. An annular ring belt region depends from the upper combustion surface, a pair of skirt panels depend from the ring belt region, and a pair of pin bosses depend from the undercrown surface to provide laterally spaced pin bores aligned along a pin bore axis for receipt of a wrist pin. The undercrown surface forms a central undercrown surface, and a portion of either an open outer cooling gallery, a sealed outer cooling gallery, or an outer galleryless region, wherein an insulating coating is applied to at least one of the portions of the undercrown surface.

A thermally compensated bore guide system for a shaft, the shaft configured to translate along a longitudinal axis, is provided. The thermally compensated bore guide system includes an inner bore defined within a component. The inner bore is configured to circumferentially surround at least a portion of the shaft, wherein the inner bore is non-linear in response to the thermally compensated bore guide system being at a first thermal condition and wherein the inner bore is configured to be linear and to define a bore axis substantially aligned with the longitudinal axis in response to the thermally compensated bore guide system being at a second thermal condition.

A foundry core formed from a moulding sand, grains of which are bound together by a binder, and which is provided to form a cooling channel in an engine block for an internal combustion engine. The foundry core has a supporting section, two neck sections, which protrude from a lateral surface of the supporting section and are arranged at a distance from one another, and at least one bridge section which is held by the neck sections at a distance from the supporting section and a minimum thickness of which measured as the distance between its lateral surfaces is no more than 3 mm in an area which lies between the neck sections.