Disclose is a copper alloy for a laser cladding valve seat. the copper alloy may include an amount of about 15.0 to 25.0 wt % of Ni, an amount of about 1.0 to 4.0 wt % of Si, an amount of about 0.5 to 1.0 wt % of B, an amount of about 1.0 to 2.0 wt % of Cr, an amount of about 5.0 to 15.0 wt % of Co, an amount of about 2.0 to 20.0 wt % of Mo, an amount of about 0.1 to 0.5 wt % of Ti and the balance Cu, all the wt % based on the total weight of the copper alloy. Particularly, the copper alloy may not include Fe, and may include Ti silicacide. Further disclosed is a laser cladding valve seat including the copper alloy, which does not generate cracks and is excellent in wear resistance.

A valve seat formed within an aluminum engine component includes a valve seat surface machined within the aluminum engine component, a layer of copper alloy material laser clad onto the valve seat surface of the aluminum engine component, the layer of copper alloy material having a thickness of less than 2.0 millimeters, and a layer of copper alloy/tool steel carbide material laser clad onto the layer of copper alloy material, the layer of copper alloy/tool steel carbide material having an average thickness of less than 0.5 millimeters, wherein the layer of copper alloy/tool steel carbide material has an outer surface that is machined to a final valve seat profile.

A valve seat formed within an aluminum engine component includes a valve seat surface machined within the aluminum engine component, a layer of copper alloy material laser clad onto the valve seat surface of the aluminum engine component, the layer of copper alloy material having a thickness of less than 2.0 millimeters, and a layer of copper alloy/tool steel carbide material laser clad onto the layer of copper alloy material, the layer of copper alloy/tool steel carbide material having an average thickness of less than 0.5 millimeters, wherein the layer of copper alloy/tool steel carbide material has an outer surface that is machined to a final valve seat profile.

The present disclosure provides a Ni-based alloy and a valve made of the same. The Ni-based alloy includes, on a weight basis: about 14%-17% Cr, about 4%-6% Al, about 1.0%-1.5% Ti, about 8%-11% Co, about 6%-9% W, about 0.5%-1.5% Ta, no more than about 0.25% Fe, about 0-2.0% Mo, about 0.07%-0.18% C, about 0.01%-0.03% Zr, about 0.005%-0.015% B, a balance of Ni, and incidental impurities. The Ni-based alloy, when used to fabricate engine valves, may significantly improve the corrosion resistance and oxidation resistance of the engine vales. The engine valves may also possess other desirable properties, such as high fatigue strength, high tensile strength and good weldability. The engine valves may also have extended useable life. The cost for manufacturing such engine valves may also be reduced.

A sliding member of the present invention includes a coating on a base material. The coating contains hard metal particles and corrosion-resistant metal particles that have hardness lower than that of the hard metal particles. The hard metal particles contain particles that have at least Vickers hardness of 600 Hv or higher. The corrosion-resistant metal particles are made of at least one kind of metal selected from the group consisting of copper (Cu), cobalt (Co), chromium (Cr), and nickel (Ni), or are made of an alloy containing said metal. The coating has a cross section in which the hard metal particles are dispersed in an island manner in a particle aggregate of the corrosion-resistant metal particles and in which an area ratio of the corrosion-resistant metal particles is 30% or larger. Thus, corrosion of the hard metal particles in the coating is prevented, whereby the sliding member maintains wear resistance for a long time.

An intake valve for an internal combustion engine is provided. The intake valve includes a valve stem with a hole in the valve stem forming an air channel there through that allows intake air to flow from an intake passage, through the air channel, into a cylinder of the internal combustion engine.

A method of improving corrosion resistance of a cylinder cover including a port that is an intake port or an exhaust port. The cylinder cover is configured such that an annular cooling water passage is formed between an inner peripheral surface of the port and a valve seat ring when the valve seat ring is inserted in the port. The method includes forming a weld overlay layer on each of sealed regions of the inner peripheral surface of the port by laser metal deposition using a welding material made of a nickel-based alloy, a copper alloy, stainless steel, or a titanium alloy, the sealed regions being positioned at both sides of the cooling water passage, respectively.

An engine valve having a shaft portion and a head portion expanding in diameter like a head at an edge of the shaft portion, and being to open and close a port provided in a cylinder head, wherein the head portion has a head front surface on a bottom side facing a combustion chamber side, a head rear surface on a top side facing the port side, and an outer peripheral surface of the head portion formed between the head front surface and the head rear surface, and the head portion is provided a mirror-finished mirror portion, and the head portion is provided a mirror-finished mirror portion on the entire area of the head front surface exposed to the combustion chamber and the entire area of the outer peripheral surface exposed to the combustion chamber.

An iron-base sintered alloy material includes a matrix phase, Co base inter-metallic compound particles having hardness of 600 to 1200 HV, carbide-type particles having hardness of 400 to 700 HV, and optionally solid-lubricant particles, the particles being dispersed in the matrix phase. A matrix part including the matrix phase and the two kinds of hard-particles contains 0.3 to 1.5% by mass of C, and 10 to 50% by mass of one or more kinds selected from Si, Mo, Cr, Ni, Co, Mn, S, N, V, Ca, F, Mg, and O, the balance being Fe and unavoidable impurities. By dispersing, in the matrix phase, the Co base inter-metallic compound particles having high hardness, and the carbide-type particles having low hardness and low aggressiveness to mated material and increasing mechanical strength, wear-resistance can be improved with low aggressiveness to mated material and high radial crushing strength (350 MPa or more).

An iron-base sintered alloy material includes a matrix phase, Co base inter-metallic compound particles having hardness of 600 to 1200 HV, carbide-type particles having hardness of 400 to 700 HV, and optionally solid-lubricant particles, the particles being dispersed in the matrix phase. A matrix part including the matrix phase and the two kinds of hard-particles contains 0.3 to 1.5% by mass of C, and 10 to 50% by mass of one or more kinds selected from Si, Mo, Cr, Ni, Co, Mn, S, N, V, Ca, F, Mg, and O, the balance being Fe and unavoidable impurities. By dispersing, in the matrix phase, the Co base inter-metallic compound particles having high hardness, and the carbide-type particles having low hardness and low aggressiveness to mated material and increasing mechanical strength, wear-resistance can be improved with low aggressiveness to mated material and high radial crushing strength (350 MPa or more).