A galleryless piston having a reduced temperature during operation in an engine is provided. The piston includes an upper wall with an exposed undercrown surface. A ring belt and pin bosses depend from the upper wall, and a pair of skirt panels depend from the ring belt and are coupled to the pin bosses by struts. The piston includes an inner undercrown region and outer pockets extending along the undercrown surface. The inner undercrown region is surrounded by the skirt panels, the struts, and the pin bosses. Each outer pocket is surrounded by one of the pin bosses, a portion of the ring belt, and the struts adjacent the one pin boss. A plurality of holes extend through the pin bosses and/or the struts from the inner undercrown region to one of the outer pockets to convey cooling oil from the inner undercrown region to the outer pockets.

The invention relates to a method for producing an engine component, in particular a piston for an internal combustion engine, wherein an aluminum alloy is cast in the gravity die casting process and wherein the aluminum alloy has 7 to <14.5 wt % silicon, >1.2 to ≦4 wt % nickel, >3.7 to <10 wt % copper, <1 wt % cobalt, 0.1 to 1.5 wt % magnesium, 0.1 to ≦0.7 wt % iron, 0.1 to ≦0.7 wt % manganese, >0.1 to <0.5 wt % zirconium, ≧0.1 to ≦0.3 wt % vanadium, 0.05 to 0.5 wt % titanium, and 0.004 to ≦0.05 wt % phosphorus as alloying elements and aluminum and unavoidable contaminants as the remainder. The aluminum alloy can optionally comprise beryllium, wherein the calcium content is limited to a low level. The invention further relates to an engine component, in particular a piston for an internal combustion engine, wherein the engine component is composed at least partially of an aluminum alloy, and to the use of an aluminum alloy to produce an engine component, in particular a piston of an internal combustion engine.

A nodular graphite cast iron for pistons according to an embodiment contains, in mass %, C: 2.7 to 4.3%, Si: 2.0 to 3.5%, Mn: 0.3 to 0.8%, Mg: 0.02 to 0.10%, Cu: 0.3 to 1.0%, Cr: 0.05 to 0.90%, and Mo: 0.05 to 1.00% with the balance being composed of Fe and inevitable impurities. Then, the C content and the Si content fall within a composition range defined by a line sequentially joining respective points of point A (2.7%, 3.5%), point B (3.2%, 2.0%), point C (4.3%, 2.0%), and point D (3.8%, 3.5%) indicated by (the C content and the Si content) in a graph illustrating the relation between the C content and the Si content.

A piston for an internal combustion engine includes a piston head and a piston skirt, wherein the piston head has a piston base, a circumferential ring part and, in the region of the ring part, a circumferential closed cooling channel or sealed cavity. An inner side of the piston has two lower surfaces which transform continuously in the region of the piston central axis (M) to form an arched surface. The piston skirt has piston hubs provided with hub bores which are interconnected by means of running surfaces which have inner surfaces facing the inside of the piston. Starting from the free ends of the piston skirt, inside the piston on the pressure side (DS) and/or counter pressure side (GDS), an inner surface of a running surface continuously transforms into a guiding surface for a coolant which transforms continuously on the side thereof into a lower surface.

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.

To provide a surface structure of an aluminum-based member which can further improve heat insulating properties and heat shielding properties of the aluminum-based member. In an aluminum-based member 1 containing at least a silicon composition, a porous oxide film 2 is provided on a surface of the aluminum-based member 1, and the oxide film 2 is constituted to have at least a pore 2a extending from the surface toward an inside in a thickness direction of the oxide film 2 and a void 3a present inside the silicon composition 3 extending in a direction substantially orthogonal to the thickness direction of the oxide film 2.

A sprayed coating for a sliding member of the present invention includes a ferrous alloy containing iron (Fe) as a major ingredient.

The sprayed coating for the sliding member containing 10 mass % or more and 20 mass % or less of chromium (Cr), and 0.1 mass % or more and 0.5 mass % or less of silicon (Si) and having the content rate of an oxide in the sprayed coating of 1 area % or less has corrosion resistance with improved seizure resistance.

A sprayed coating for a sliding member of the present invention includes a ferrous alloy containing chromium (Cr).

The sprayed coating for the sliding member has the content rate of the chromium of 8 mass % or more, includes a structure that comprises crystal grains contained in the sprayed coating and having an average grain size of 3 μm or less, has a Vickers hardness of 300 Hv or more, and then is excellent at abrasion resistance.

An aluminum alloy for a piston may include aluminum (Al) as a base, magnesium (Mg) and zinc (Zn); and wherein the magnesium content is 10-20 wt % with reference to the total weight. In the aluminum alloy, the zinc content is 2.0-6.4 wt % with reference to the total weight. The aluminum alloy further includes copper (Cu) of 1.5-3.5 wt % with reference to the total weight. In the aluminum alloy, T-AlCuMgZn phase is generated.

A piston of a cylinder of an internal combustion engine includes: an upper piston crown; a radially outer surface; a plurality grooves arranged on the radially outer surface; and a plurality of piston rings each positioned in a respective one of the grooves. The radially outer surface forms a top land arranged between the upper piston crown and an uppermost one of the grooves of the piston, and the top land has an axial length and a non-abrasion-proof coating.