The present invention relates to matter alloys including copper.

The present invention relates to matter alloys including copper.

A copper alloy for valve seats, and more particularly a copper alloy for valve seats with improved wear resistance, contains 12 to 24% by weight of Ni, 2 to 4% by weight of Si, 7 to 13% by weight of Cr, 20 to 35% by weight of Fe, and a balance of Cu and other impurities.

A copper alloy for valve seats, and more particularly a copper alloy for valve seats with improved wear resistance, contains 12 to 24% by weight of Ni, 2 to 4% by weight of Si, 7 to 13% by weight of Cr, 20 to 35% by weight of Fe, and a balance of Cu and other impurities.

The present disclosure provides a high-strength and high-plasticity casting high-entropy alloy (HEA), having a general formula of Al.sub.aCo.sub.bCr.sub.cTi.sub.dFe.sub.eNi.sub.fCu.sub.g, where 6.0<a≤8.0, 18.0<b≤23.0, 7.5≤c<12.5, 2.0<d≤8.5, 15.5<e≤20.0, 28.0<f≤37.0, 0.2<g≤10.0, and a+b+c+d+e+f+g=100. The casting HEA can be prepared in one step and has excellent mechanical properties. The various metal raw materials are environmental-friendly and suitable for large-scale industrial production.

The present disclosure provides a high-strength and high-plasticity casting high-entropy alloy (HEA), having a general formula of Al.sub.aCo.sub.bCr.sub.cTi.sub.dFe.sub.eNi.sub.fCu.sub.g, where 6.0<a≤8.0, 18.0<b≤23.0, 7.5≤c<12.5, 2.0<d≤8.5, 15.5<e≤20.0, 28.0<f≤37.0, 0.2<g≤10.0, and a+b+c+d+e+f+g=100. The casting HEA can be prepared in one step and has excellent mechanical properties. The various metal raw materials are environmental-friendly and suitable for large-scale industrial production.

A permanent magnet in which demagnetization adjustment can be easily performed and a method for manufacturing the same are provided. The permanent magnet contains 22 to 28 mass % of a rare-earth element R, 12 to 23 mass % of Fe, 3 to 9 mass % of Cu, 1 to 4 mass % of Zr, and a remainder consisting of Co and unavoidable impurities, in which, in a demagnetization curve in which the horizontal axis indicates a demagnetization field (kOe) and the vertical axis indicates the total amount of magnetic flux (×10.sup.−5 WbT) in the permanent magnet, the slope of an approximate straight line in demagnetization field ranges from 0 to −11 kOe is 1.2 or smaller.

A permanent magnet in which demagnetization adjustment can be easily performed and a method for manufacturing the same are provided. The permanent magnet contains 22 to 28 mass % of a rare-earth element R, 12 to 23 mass % of Fe, 3 to 9 mass % of Cu, 1 to 4 mass % of Zr, and a remainder consisting of Co and unavoidable impurities, in which, in a demagnetization curve in which the horizontal axis indicates a demagnetization field (kOe) and the vertical axis indicates the total amount of magnetic flux (×10.sup.−5 WbT) in the permanent magnet, the slope of an approximate straight line in demagnetization field ranges from 0 to −11 kOe is 1.2 or smaller.

A composition of a copper alloy for a laser cladding valve sheet is disclosed. The copper alloy includes a matrix structure and a hard phase, which includes 12 to 24 wt % of Ni, 2 to 4 wt % of Si, 8 to 30 wt % of Fe, more than 5 wt % and less than 10 wt % of Mo, 2 to 10 wt % of Al, and the balance Cu. The interfacial delamination may be suppressed in a fatigue environment by micronizing the hard phase and the distribution thereof, thereby improving fatigue resistance and wear resistance.

A composition of a copper alloy for a laser cladding valve sheet is disclosed. The copper alloy includes a matrix structure and a hard phase, which includes 12 to 24 wt % of Ni, 2 to 4 wt % of Si, 8 to 30 wt % of Fe, more than 5 wt % and less than 10 wt % of Mo, 2 to 10 wt % of Al, and the balance Cu. The interfacial delamination may be suppressed in a fatigue environment by micronizing the hard phase and the distribution thereof, thereby improving fatigue resistance and wear resistance.