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 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.

The manufacturing method of a porous silicon material of the present disclosure includes a particle forming step of melting a raw material containing Al as a first element in an amount of 50% by mass or more and Si in an amount of 50% by mass or less to obtain a silicon alloy, a pore forming step of removing the first element from the silicon alloy to obtain a porous material, and a heat treatment step of heating the porous material to diffuse elements other than Si to a surface of the porous material.

Tools, for example, fixed cutter drill bits, may be manufactured to include hard composite portions having reinforcing particles dispersed in a continuous binder phase and auxiliary portions that are more machinable than the hard composite portions. For example, a tool may include a hard composite portion having a machinability rating 0.2 or less; and an auxiliary portion having a machinability rating of 0.6 or greater in contact with the hard composite portion. The boundary or interface between the hard composite portion and the auxiliary portion may be designed so that upon removal of the most or all of the auxiliary portion the resultant tool has a desired geometry without having to machine the hard composite portion.

A graphene and in-situ nano-ZrB.sub.2 particle-co-reinforced aluminum matrix composite (AMC) and a preparation method thereof are provided. The preparation method includes: heating an aluminum alloy for melting, adding potassium fluoroborate and potassium fluorozirconate to produce ZrB.sub.2 particles in-situ, additionally adding a mixture of pre-prepared copper-coated graphene and an aluminum powder, and stirring with an electromagnetic field for uniform dispersion; and ultrasonically treating the resulting melt to improve the dispersion of the in-situ nano-ZrB.sub.2 particles and the graphene, casting for molding to obtain a casting, and subjecting the casting to homogenization and rolling for deformation to obtain the graphene and in-situ nano-ZrB.sub.2 particle-co-reinforced AMC. The in-situ generation of the reinforcement nano-ZrB.sub.2 particles in an aluminum alloy melt increases the number of interfaces in the composite and also increases the dislocation density.

The invention relates to a method of processing a superhard composite material (21) comprising a polycrystalline microstructure and a binder, said method comprising the following steps: contacting (200) a surface of said superhard composite material (21) with an absorbent material (30), and applying (300) an electric current to the superhard composite material (21), causing the binder to move from the superhard composite material (21) to the absorbent material (30) so as to create a continuous gradient (221) of binder content within the superhard composite material (21).

Methods of forming larger sintered compacts of PCD and other sintered ultrahard materials are disclosed. Improved solvent metal compositions and layering of the un-sintered construct allow for sintering of thicker and larger high quality sintered compacts. Jewelry may also be made from sintered ultrahard materials including diamond, carbides, and boron nitrides. Increased biocompatibility is achieved through use of a sintering metal containing tin. Methods of sintering perform shapes are provided.

A cutting element includes a polycrystalline diamond layer having a cutting face and a diamond layer side surface, a substrate attached to the polycrystalline diamond layer, the substrate having a bottom surface and a substrate side surface, an interface between the diamond layer and the substrate, and a mask covering at least the bottom surface and the substrate side surface of the cutting element.

Polycrystalline diamond compacts having parting compound within the interstitial volumes are disclosed herein. In one embodiment, a polycrystalline diamond compact includes a polycrystalline diamond body having a plurality of diamond grains bonded together in diamond-to-diamond bonds, interstitial volumes positioned between the adjacent diamond grains, and a parting compound positioned in at least a portion of the interstitial volumes of the polycrystalline diamond body.