The disclosure relates to a method for preparing Ti(C,N)-based superhard metal composite materials, with Ti(C,N) powder and (W,Mo,Ta)(C,N) powder as main raw materials and Co powder as binding phase for preparation, thereby obtaining a material in which a microstructure is a double-core rim structure that has both a black core rim and a white core rim. The material has a complete and evenly distributed double-core rim structure. In the condition that the ensured hardness of the material is not reduced and even slightly increased, the toughness of the material is significantly improved, wherein the fracture toughness of the material is in the range of 11.3 to 12.5 MPa.Math.m.sup.1/2.

The cutting insert may include a substrate including a first surface, a second surface, and a cutting edge. The substrate may include a hard phase and a binder phase, and the hard phase may include a first hard phase and a second hard phase. In X-ray diffraction analysis, a peak of the first hard phase may be observed on a higher angle side than a peak of the second hard phase. The second hard phase in the second surface may include a compressive residual stress of 150 MPa or more. A maximum height (Rz) in the second surface may be 0.2 to 1.5 μm. A maximum height of the cutting edge may be 2 to 30 times the maximum height in the second surface.

The cutting insert may include a substrate including a first surface, a second surface, and a cutting edge. The substrate may include a hard phase and a binder phase, and the hard phase may include a first hard phase and a second hard phase. In X-ray diffraction analysis, a peak of the first hard phase may be observed on a higher angle side than a peak of the second hard phase. The second hard phase in the second surface may include a compressive residual stress of 150 MPa or more. A maximum height (Rz) in the second surface may be 0.2 to 1.5 μm. A maximum height of the cutting edge may be 2 to 30 times the maximum height in the second surface.

A coated tool of the present disclosure may include a base and a coating layer covering at least a part of the base. The base may include a hard phase of a carbonitride including Ti and a binder phase including at least one of Co and Ni and has a thermal expansion coefficient at 25 to 1000° C. of 9.0×10.sup.−6/° C. or more. The coating layer may include a TiCN layer and an Al.sub.2O.sub.3 layer positioned on the TiCN layer. The TiCN layer may have a compressive stress of 250 to 500 MPa. The Al.sub.2O.sub.3 layer may have a thickness of 2 μm or more and a compressive stress of 450 MPa or more, and the value of the compressive stress is greater than the compressive stress of the TiCN layer.

A coated tool of the present disclosure may include a base and a coating layer covering at least a part of the base. The base may include a hard phase of a carbonitride including Ti and a binder phase including at least one of Co and Ni and has a thermal expansion coefficient at 25 to 1000° C. of 9.0×10.sup.−6/° C. or more. The coating layer may include a TiCN layer and an Al.sub.2O.sub.3 layer positioned on the TiCN layer. The TiCN layer may have a compressive stress of 250 to 500 MPa. The Al.sub.2O.sub.3 layer may have a thickness of 2 μm or more and a compressive stress of 450 MPa or more, and the value of the compressive stress is greater than the compressive stress of the TiCN layer.

The invention relates to a compacted and densified metal material having one or more phases formed of an agglomerate of grains, the cohesion of the material being provided by bridges formed between grains, said material having a relative density higher than or equal to 95% and preferably higher than or equal to 98%.

The invention relates to a compacted and densified metal material having one or more phases formed of an agglomerate of grains, the cohesion of the material being provided by bridges formed between grains, said material having a relative density higher than or equal to 95% and preferably higher than or equal to 98%.

A hard material includes a first hard phase containing titanium carbonitride as a major constituent and a binder phase containing an iron group element as a major constituent. In any surface or cross-section of the hard material, the grain size D50 at a cumulative percentage of 50% of a grain size distribution by area of the first hard phase is 1.0 μm or more, and the average aspect ratio of first hard phase particles having grain sizes larger than or equal to D50 is 2.0 or less.

A hard material includes a first hard phase containing titanium carbonitride as a major constituent and a binder phase containing an iron group element as a major constituent. In any surface or cross-section of the hard material, the grain size D50 at a cumulative percentage of 50% of a grain size distribution by area of the first hard phase is 1.0 μm or more, and the average aspect ratio of first hard phase particles having grain sizes larger than or equal to D50 is 2.0 or less.

A cemented carbide composed of a first hard phase, a second hard phase and a binder phase, in which the first hard phase is composed of tungsten carbide particles, the second hard phase is composed of at least one first compound selected from the group consisting of TiNbC, TiNbN and TiNbCN, the second hard phase has an average particle diameter of no more than 0.1 μm, the second hard phase has a dispersity of no more than 0.7, the second hard phase has a content of no less than 0.1 vol % and no more than 15 vol %, the binder phase contains at least one first element selected from the group consisting of iron, cobalt and nickel, and the binder phase has a content of no less than 0.1 vol % and no more than 20 vol %.