Permanent magnet, motor, and generator

A method of manufacturing a permanent magnet, comprising:

• press-forming alloy powder in a magnetic field to fabricate a compression molded body, wherein a total weight of the compression molded body is not less than 200 g nor more than 2000 g;
• sintering the compression molded body to fabricate a sintered body;
• performing a solution heat treatment on the sintered body;
• and
• performing an aging heat treatment on sintered body after the solution heat treatment,
• wherein the solution heat treatment includes:
• performing a heat treatment on a treatment object having the sintered body at a temperature TST of 1100 to 1200° C. inside a heating chamber having a heater;
• transferring a cooling member into the heating chamber after the heat treatment and placing the cooling member between the heater and the treatment object, the cooling member including a first layer and a second layer on the first layer, the first layer having a first thermal emissivity of 0.5 or more, the second layer having a second thermal emissivity lower of less than 0.5, the first layer containing carbon, a metal carbide, a metal oxide, or a refractory brick, the second layer containing copper, molybdenum, tungsten, titanium, or stainless steel, and the first layer being faced with the treatment object;
• and
• transferring the treatment object together with the cooling member to the outside of the heating chamber, and cooling the treatment object until a temperature of the treatment object becomes a temperature lower than a temperature TST−200° C.,
• wherein in cooling the treatment object, a cooling rate until the temperature of the treatment object becomes the temperature TST−200° C. is 5° C./s or more, wherein the cooling rate is achieved by a combination of absorbing, by the first layer, heat emitted by the treatment object and reflecting, by the second layer, heat emitted from the heater, and
• wherein the permanent magnet is expressed by a composition formula:
• RpFeqMrCutCo100-p-q-r-t,
• where R represents at least one element selected from the group consisting of rare earth elements, M represents at least one element selected from the group consisting of Zr, Ti, and Hf, p is a number satisfying 10.5≤p≤12.5 atomic percent, q is a number satisfying 27≤q≤40 atomic percent, r is a number satisfying 0.88≤r≤4.5 atomic percent, and t is a number satisfying 4.5≤t≤10.7 atomic percent.