The present invention relates to a binder composition for metal powder injection molding, and more specifically, to a binder composition for metal powder injection molding, which can be promptly debound, facilitates the setting of flow conditions in an injection process, and enables the minimization of poor debinding such as swelling, carbonization of low-molecular-weight binders, and other internal defects, during a debinding process.

The binder composition for metal powder injection molding of the present invention contains 10 to 50 wt % of a high-viscosity polyoxymethylene polymer and 50 to 90 wt % of a low-viscosity polyoxymethylene polymer.

By containing polyoxymethylenes alone, which has been produced with different viscosities, without feeding of other monomers in the polymerization process of polyoxymethylene, the binder composition for metal powder injection molding according to the present invention is more economical through low manufacturing costs compared with a conventional technique in which the rate of decomposition by a gas-phase acid is controlled by viscosity adjustment in a polymerization process, and has excellent injection characteristics and debinding/sintering characteristics compared with a technique in which polyoxymethylene and other polymer resins, such as polyolefins and polyamides, are used together.

An injection molding composition contains a titanium-based powder containing titanium as a main component and having an average particle diameter of 15 μm or more and 35 μm or less, a ceramic powder containing a ceramic as a main material and having an average particle diameter of 1 nm or more and 100 nm or less, and an organic binder. The ceramic is an oxide-based ceramic containing an oxide as a main component, and a standard free energy of formation of the oxide at 1000° C. may be lower than a standard free energy of formation of titanium oxide at 1000° C.

An injection molding composition contains a titanium-based powder containing titanium as a main component and having an average particle diameter of 15 μm or more and 35 μm or less, a ceramic powder containing a ceramic as a main material and having an average particle diameter of 1 nm or more and 100 nm or less, and an organic binder. The ceramic is an oxide-based ceramic containing an oxide as a main component, and a standard free energy of formation of the oxide at 1000° C. may be lower than a standard free energy of formation of titanium oxide at 1000° C.

A method is shown for manufacturing a hardened gripping element for a sealing and restraint system used for forming a pipe joint in a fluid pipeline. Instead of machining the gripping elements used in the system from a metal stock, a special series of metal injection molding steps are utilized. A metal polymer composite mix is first formed having a metal particulate phase and a polymer phase. A green metal composite article is formed by either extruding the composite mix or molding the composite mix into a metal polymer composite article having at least one gripping surface having a plurality of gripping teeth. The composite article is subjected to thermal debinding and sintering to produce a finished or near finished hardened gripping element.

A drilling tool includes a drive assembly with a shank that is configured to couple to a power tool and a step drill bit. The step drill bit includes a body having a proximal end adjacent the shank, a distal end opposite the proximal end, and a bit axis extending centrally through the body between the proximal end and the distal end. The body is defined by a wall extending around the bit axis to define a hollow interior cavity of the body. The step drill bit also includes a plurality of axially stacked, progressively sized steps with a first step at the proximal end and a terminal step at the distal end and a flute extending from the proximal end to the distal end. The flute defines a cutting edge.

A drilling tool includes a drive assembly with a shank that is configured to couple to a power tool and a step drill bit. The step drill bit includes a body having a proximal end adjacent the shank, a distal end opposite the proximal end, and a bit axis extending centrally through the body between the proximal end and the distal end. The body is defined by a wall extending around the bit axis to define a hollow interior cavity of the body. The step drill bit also includes a plurality of axially stacked, progressively sized steps with a first step at the proximal end and a terminal step at the distal end and a flute extending from the proximal end to the distal end. The flute defines a cutting edge.

A metal powder for powder metallurgy contains Co as a principal component, Cr at 16 mass % or more and 35 mass % or less, and Si at 0.3 mass % or more and 2.0 mass % or less, wherein when one element selected from Ti, V, Y, Zr, Nb, Hf, and Ta is a first element, and one element selected from the group and having a higher group number in the periodic table than that of the first element or having the same group number in the periodic table as that of the first element and a higher period number than that of the first element is a second element, the first element is at 0.01 mass % or more and 0.5 mass % or less, and the second element is at 0.01 mass % or more and 0.5 mass % or less.

A metal powder for powder metallurgy contains Co as a principal component, Cr at 16 mass % or more and 35 mass % or less, and Si at 0.3 mass % or more and 2.0 mass % or less, wherein when one element selected from Ti, V, Y, Zr, Nb, Hf, and Ta is a first element, and one element selected from the group and having a higher group number in the periodic table than that of the first element or having the same group number in the periodic table as that of the first element and a higher period number than that of the first element is a second element, the first element is at 0.01 mass % or more and 0.5 mass % or less, and the second element is at 0.01 mass % or more and 0.5 mass % or less.

The present invention provides a soft magnetic composite material for a fluid filling process, comprising soft magnetic powder and a binder. The soft magnetic powder and the binder are fully mixed, the soft magnetic powder is higher in average Wadell's sphericity, and the soft magnetic powder high in average Wadell's sphericity is small in friction force generated when flowing, small in specific surface area and large in apparent density.

By melting a shaping material in which a metal powder and a binder are mixed and by carrying out injection molding (primary shaping) in an injection mold, an injection molded body, or an intermediate shaped body are produced. The injection molded body or the intermediate shaped body is placed by a transfer mold and is subjected to a gravity shaping (secondary shaping) with a transformation. A sintered body is manufactured by carrying out debindering and sintering to the injection molded body.