An iron-based sintered alloy material having, at the surface of the material, a hardened layer exhibiting a martensite phase containing a solid solution of nitrogen in a supersaturated state. The iron-based sintered alloy material may contain at least one of chromium, copper, molybdenum, manganese and nickel. A production method for the iron-based sintered alloy material includes: subjecting an iron-based sintered alloy substrate containing carbon to a nitriding treatment by heating the substrate to a nitriding temperature of at least 590° C. in an atmosphere containing ammonia, and then performing quenching by rapidly cooling the substrate.

Provided is an Fe-based nanocrystalline alloy powder. The Fe-based nanocrystalline alloy powder has a chemical composition, excluding inevitable impurities, represented by a composition formula of Fe.sub.aSi.sub.bB.sub.cP.sub.dCu.sub.eM.sub.f, where the M in the composition formula is at least one element selected from the group consisting of Nb, Mo, Zr, Ta, W, Hf, Ti, V, Cr, Mn, C, Al, S, O, and N, 79 at %≤a≤84.5 at %, 0 at %≤b<6 at %, 0 at %<c≤10 at %, 4 at %<d≤11 at %, 0.2 at %≤e≤0.53 at %, 0 at %≤f≤4 at %, a+b+c+d+e+f=100 at %, a degree of crystallinity is more than 10% by volume, and an Fe crystallite diameter of the Fe-based nanocrystalline alloy powder is 50 nm or less.

Provided is an Fe-based nanocrystalline alloy powder. The Fe-based nanocrystalline alloy powder has a chemical composition, excluding inevitable impurities, represented by a composition formula of Fe.sub.aSi.sub.bB.sub.cP.sub.dCu.sub.eM.sub.f, where the M in the composition formula is at least one element selected from the group consisting of Nb, Mo, Zr, Ta, W, Hf, Ti, V, Cr, Mn, C, Al, S, O, and N, 79 at %≤a≤84.5 at %, 0 at %≤b<6 at %, 0 at %<c≤10 at %, 4 at %<d≤11 at %, 0.2 at %≤e≤0.53 at %, 0 at %≤f≤4 at %, a+b+c+d+e+f=100 at %, a degree of crystallinity is more than 10% by volume, and an Fe crystallite diameter of the Fe-based nanocrystalline alloy powder is 50 nm or less.

A powder composition is used for the fabrication of casting inserts, designed to produce local composite zones resistant to abrasive wear. The composite zones are reinforced with carbides and borides or with mixtures thereof formed in situ in castings. The powder includes powder reactants of the formation of carbides and/or borides selected from the group of TiC, WC, ZrC, NbC, TaC, TiB2, ZrB2, or mixtures thereof. The carbides and/or borides forming after crystallization particles reinforces the composite zones in castings. The powder composition further includes moderator powders in the form of a mixture of metal powders, which after crystallization form matrix of the composite zone in casting. A casting insert is disclosed for the fabrication in casting of local composite zones resistant to abrasive wear. A method for the fabrication of local composite zones in castings uses for this purpose the reaction of the self-propagating high temperature synthesis (SHS).

A powder composition is used for the fabrication of casting inserts, designed to produce local composite zones resistant to abrasive wear. The composite zones are reinforced with carbides and borides or with mixtures thereof formed in situ in castings. The powder includes powder reactants of the formation of carbides and/or borides selected from the group of TiC, WC, ZrC, NbC, TaC, TiB2, ZrB2, or mixtures thereof. The carbides and/or borides forming after crystallization particles reinforces the composite zones in castings. The powder composition further includes moderator powders in the form of a mixture of metal powders, which after crystallization form matrix of the composite zone in casting. A casting insert is disclosed for the fabrication in casting of local composite zones resistant to abrasive wear. A method for the fabrication of local composite zones in castings uses for this purpose the reaction of the self-propagating high temperature synthesis (SHS).

In a current assisted sintering method according to an embodiment includes: a pressure-molding step of molding a powder compact by pressing a powder charged in a mold a mold releasing step of releasing the powder compact from the mold; and a current assisted sintering step of forming a sintered compact by feeding an electric current through the powder compact released from the mold. In the pressure-molding step, a cylindrical mold, of which one end and the other end are opened, made of a material containing a metal is used as the mold, and the powder is pressed by a first punch inserted into the one opening and a second punch inserted into the other opening.

In a current assisted sintering method according to an embodiment includes: a pressure-molding step of molding a powder compact by pressing a powder charged in a mold a mold releasing step of releasing the powder compact from the mold; and a current assisted sintering step of forming a sintered compact by feeding an electric current through the powder compact released from the mold. In the pressure-molding step, a cylindrical mold, of which one end and the other end are opened, made of a material containing a metal is used as the mold, and the powder is pressed by a first punch inserted into the one opening and a second punch inserted into the other opening.

A high-speed machining tool made of a steel-bonded carbide and a method for preparing the same relate to the technical field of lathe tools made of steel-bonded carbides, and overcome the problems of traditional steel-bonded carbide lathe tools about low hardness and low toughness. The high-speed machining tool includes a skeleton, a main body, and a coating. The main body is consolidated by the skeleton from inside. The skeleton and the main body are both ringlike in shape. The main body has its outer surface covered by the coating. The high-speed machining tool is such made that the skeleton is hard and the main body is tough. The blade of the tool is hard and can transfer vibrations to the main body, thereby protecting the tool from brittle fractures and improving the overall performance of the tool.

A ratio of an angle of 2 to 15° is 50% or more in an arbitrary surface of the tungsten material, the angle being formed between a specific crystal orientation of a first crystal grain and a specific crystal orientation of a second crystal grain adjacent to the first crystal grain.

A ratio of an angle of 2 to 15° is 50% or more in an arbitrary surface of the tungsten material, the angle being formed between a specific crystal orientation of a first crystal grain and a specific crystal orientation of a second crystal grain adjacent to the first crystal grain.