A porous titanium-based sintered body, having a porosity of 45% to 65%, an average pore diameter of 5 μm to 15 μm, and a bending strength of 100 MPa or more. According to the present invention, a porous titanium-based sintered body having good pore diameter and porosity that are compatible with each other and having a high strength can be provided.

The present disclosure is directed at methods of preparing rare earth-based permanent magnets having improved coercivity and remanence, the method comprising one or more steps comprising: (a) homogenizing a first population of particles of a first GBM alloy with a second population of particles of a second core alloy to form a composite alloy preform, the first GBM alloy being substantially represented by the formula: AC.sub.bR.sub.xCo.sub.yCu.sub.dM.sub.z, the second core alloy being substantially represented by the formula G.sub.2Fe.sub.14B, where AC, R, M, G, b, x, y, and z are defined; (b) heating the composite alloy preform particles to form a population of mixed alloy particles; (c) compressing the mixed alloy particles, under a magnetic field of a suitable strength to align the magnetic particles with a common direction of magnetization and inert atmosphere, to form a green body; (d) sintering the green body; and (e) annealing the sintered body. Particular embodiments include magnets comprising neodymium-iron-boron core alloys, including Nd.sub.2Fe.sub.14B.

The present disclosure is directed at methods of preparing rare earth-based permanent magnets having improved coercivity and remanence, the method comprising one or more steps comprising: (a) homogenizing a first population of particles of a first GBM alloy with a second population of particles of a second core alloy to form a composite alloy preform, the first GBM alloy being substantially represented by the formula: AC.sub.bR.sub.xCo.sub.yCu.sub.dM.sub.z, the second core alloy being substantially represented by the formula G.sub.2Fe.sub.14B, where AC, R, M, G, b, x, y, and z are defined; (b) heating the composite alloy preform particles to form a population of mixed alloy particles; (c) compressing the mixed alloy particles, under a magnetic field of a suitable strength to align the magnetic particles with a common direction of magnetization and inert atmosphere, to form a green body; (d) sintering the green body; and (e) annealing the sintered body. Particular embodiments include magnets comprising neodymium-iron-boron core alloys, including Nd.sub.2Fe.sub.14B.

The present disclosure is directed at methods of preparing rare earth-based permanent magnets having improved coercivity and remanence, the method comprising one or more steps comprising: (a) homogenizing a first population of particles of a first GBM alloy with a second population of particles of a second core alloy to form a composite alloy preform, the first GBM alloy being substantially represented by the formula: AC.sub.bR.sub.xCo.sub.yCu.sub.dM.sub.z, the second core alloy being substantially represented by the formula G.sub.2Fe.sub.14B, where AC, R, M, G, b, x, y, and z are defined; (b) heating the composite alloy preform particles to form a population of mixed alloy particles; (c) compressing the mixed alloy particles, under a magnetic field of a suitable strength to align the magnetic particles with a common direction of magnetization and inert atmosphere, to form a green body; (d) sintering the green body; and (e) annealing the sintered body. Particular embodiments include magnets comprising neodymium-iron-boron core alloys, including Nd.sub.2Fe.sub.14B.

A laser-solid-forming manufacturing device includes a laser emitter, a magnetic field generator, and a forming platform. The laser emitter emits a laser beam which acts on a feedstock to form a molten pool. The magnetic field generator includes a spiral copper coil, a first electrode and a second electrode. The spiral copper coil is formed by spirally winding a copper tube. The first and second electrodes are arranged at respective ends of the copper tube and are used for loading a voltage to generate a magnetic field in the spiral copper coil. At any time, the spiral copper coil sleeves an action point of the laser beam and the feedstock. A corresponding laser-solid-forming manufacturing method is also presented.

A method of making sintered components made from an iron-based powder composition and the sintered component per se. The method is especially suited for producing components which will be subjected to wear at elevated temperatures, consequently the components consists of a heat resistant stainless steel with hard phases including chromium carbo-nitrides. Examples of such components are parts in turbochargers for internal combustion engines.

Provided is a valve seat insert for an internal combustion engine, which has both an excellent heat dissipation property and excellent wear resistance. The valve seat insert for an internal combustion engine is used while being press-fitted into an aluminum alloy cylinder head, is made of an iron-based sintered alloy, is formed by integrating two layers of a functional member side layer and a supporting member side layer, and has a plating film on at least an outer peripheral side. The plating film is preferably a copper plating film. The plating film is a plating film having a thickness of 1 to 100 μm and a hardness of 50 to 300 HV, and the hardness of the plating film is adjusted so as to satisfy a range of 1.05 to 4.5 times hardness of the cylinder head in Vickers hardness HV. Pores contained in the valve seat insert are preferably sealed with a curable resin before plating treatment. Consequently, a valve seat insert for an internal combustion engine which does not go through complicated processes, is not accompanied by a significant decrease in wear resistance compared with the prior art, and has an excellent heat dissipation property is provided. If a roughened surface region is further formed at at least one portion on the outer peripheral surface of the valve seat insert in addition to the plating film, a falling out resistance property is improved. The same effect can be obtained even if the valve seat insert is a single layer of only the functional member side layer.

Provided is a valve seat insert for an internal combustion engine, which has both an excellent heat dissipation property and excellent wear resistance. The valve seat insert for an internal combustion engine is used while being press-fitted into an aluminum alloy cylinder head, is made of an iron-based sintered alloy, is formed by integrating two layers of a functional member side layer and a supporting member side layer, and has a plating film on at least an outer peripheral side. The plating film is preferably a copper plating film. The plating film is a plating film having a thickness of 1 to 100 μm and a hardness of 50 to 300 HV, and the hardness of the plating film is adjusted so as to satisfy a range of 1.05 to 4.5 times hardness of the cylinder head in Vickers hardness HV. Pores contained in the valve seat insert are preferably sealed with a curable resin before plating treatment. Consequently, a valve seat insert for an internal combustion engine which does not go through complicated processes, is not accompanied by a significant decrease in wear resistance compared with the prior art, and has an excellent heat dissipation property is provided. If a roughened surface region is further formed at at least one portion on the outer peripheral surface of the valve seat insert in addition to the plating film, a falling out resistance property is improved. The same effect can be obtained even if the valve seat insert is a single layer of only the functional member side layer.

A method of making a cutting tool includes providing a first sintered cemented carbide body of a WC, a metallic binder phase and eta phase and wherein the substoichiometric carbon content in the cemented carbide is between −0.30 to −0.16 wt %. The first sintered cemented carbide body is subjected to a heat treatment at a temperature of between 500 to 830° C. for a time between 1 to 24 h. A cutting tool made according to the above method having an increased resistance against comb cracks is also provided.

A powder metal composition for high wear and temperature applications is made by atomizing a melted iron based alloy including 3.0 to 7.0 wt. % carbon; 10.0 to 25.0 wt. % chromium; 1.0 to 5.0 wt. % tungsten; 3.5 to 7.0 wt. % vanadium; 1.0 to 5.0 wt. % molybdenum; not greater than 0.5 wt. % oxygen; and at least 40.0 wt. % iron. The high carbon content reduces the solubility of oxygen in the melt and thus lowers the oxygen content to a level below which would cause the carbide-forming elements to oxidize during atomization. The powder metal composition includes metal carbides in an amount of at least 15 vol. %. The microhardness of the powder metal composition increases with increasing amounts of carbon and is typically about 800 to 1,500 Hv50.