A polycrystalline diamond construction has a body of polycrystalline diamond (PCD) material; and a cemented carbide substrate bonded to the body of polycrystalline material along an interface. The cemented carbide substrate has tungsten carbide particles bonded together by a binder material, the binder material comprising Co; and the tungsten carbide particles form at least around 70 weight percent and at most around 95 weight percent of the substrate. The cemented carbide substrate has a bulk volume, the bulk volume of the cemented carbide substrate having at least around 0.1 vol. % of inclusions of free carbon having a largest average size in any one or more dimensions of less than around 40 microns.

A polycrystalline diamond construction has a body of polycrystalline diamond (PCD) material; and a cemented carbide substrate bonded to the body of polycrystalline material along an interface. The cemented carbide substrate has tungsten carbide particles bonded together by a binder material, the binder material comprising Co; and the tungsten carbide particles form at least around 70 weight percent and at most around 95 weight percent of the substrate. The cemented carbide substrate has a bulk volume, the bulk volume of the cemented carbide substrate having at least around 0.1 vol. % of inclusions of free carbon having a largest average size in any one or more dimensions of less than around 40 microns.

A method for producing a sintered part, having at least the following steps: a) providing a sintered part, said sintered part having a first end face, a second end face arranged at a distance from the first end face in an axial direction, and a circumferential surface between the end faces; b) arranging the sintered part in a tool; c) applying a first pressure force, which acts on the end faces at least in the axial direction, to the sintered part by the tool; and d) applying a second pressure force, which acts on the circumferential surface at least in a radial direction, to the sintered part, wherein the sintered part is reshaped at least by the second pressure force, or mechanically processing the sintered part. Steps c) and d) are carried out at least partly simultaneously.

A method for producing a sintered part, having at least the following steps: a) providing a sintered part, said sintered part having a first end face, a second end face arranged at a distance from the first end face in an axial direction, and a circumferential surface between the end faces; b) arranging the sintered part in a tool; c) applying a first pressure force, which acts on the end faces at least in the axial direction, to the sintered part by the tool; and d) applying a second pressure force, which acts on the circumferential surface at least in a radial direction, to the sintered part, wherein the sintered part is reshaped at least by the second pressure force, or mechanically processing the sintered part. Steps c) and d) are carried out at least partly simultaneously.

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.

The invention relates to a cemented carbide composition producing method for precious metal, which includes a titanium nitride component contained therein and shows excellent workability, corrosion resistance, reduction in weight and other desirable mechanical properties, as well as the low amount of nickel used as a metallic binder and an aluminum oxide coating helps to suppress potential negative skin reactions.

The invention relates to a cemented carbide composition producing method for precious metal, which includes a titanium nitride component contained therein and shows excellent workability, corrosion resistance, reduction in weight and other desirable mechanical properties, as well as the low amount of nickel used as a metallic binder and an aluminum oxide coating helps to suppress potential negative skin reactions.

A polycrystalline diamond construction has a body of polycrystalline diamond (PCD) material; and a cemented carbide substrate bonded to the body of polycrystalline material along an interface. The cemented carbide substrate includes tungsten carbide particles bonded together by a binder material, the binder material comprising an alloy of Co, Ni and Cr; and the tungsten carbide particles form at least around 70 weight percent and at most around 95 weight percent of the substrate. The cemented carbide substrate has a bulk volume, the bulk volume of the cemented carbide substrate has at least around 0.1 vol. % of inclusions of free carbon having a largest average size in any one or more dimensions of less than around 40 microns.

A polycrystalline diamond construction has a body of polycrystalline diamond (PCD) material; and a cemented carbide substrate bonded to the body of polycrystalline material along an interface. The cemented carbide substrate includes tungsten carbide particles bonded together by a binder material, the binder material comprising an alloy of Co, Ni and Cr; and the tungsten carbide particles form at least around 70 weight percent and at most around 95 weight percent of the substrate. The cemented carbide substrate has a bulk volume, the bulk volume of the cemented carbide substrate has at least around 0.1 vol. % of inclusions of free carbon having a largest average size in any one or more dimensions of less than around 40 microns.