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.

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.

A method is presented for producing hollow microspheres of metal oxides (HMOMS) and/or hollow metal silicates microspheres (HMSMS) in a transforming solution. The transforming solution contains an atom M, or an M-ion, or a radical containing M. M in the transforming solution has the thermodynamic ability to replace silicon atoms in hollow silica microspheres (HSMS) and/or hollow glass microspheres (HGMS). The maximum temperature for transformation is set by the chemical physical properties of the transforming solution, and the viscosity of the silica in the walls of the HSMS and/or the glass in the walls of the HGMS. Viscosity, of enough magnitude, helps retain the desired shape of the hollow sphere as it is transformed to HMOMS and/or HMSMS. Non-spherical shapes can be produced by increasing the transformation temperature whereby the viscosity of the walls of the HSMS and/or the HGMS is reduced. Transformation can take place at a single temperature or at several temperatures, each temperature for a separate hold time. Methods are presented for: 1. production of micro composite castings and continuous production of sheets of micro composites, both consisting of hollow spheres in a matrix, 2. harvesting of HMOMS and HMSMS, and 3. specialty castings for anisotropic properties using 3-dimensional printing.

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.

The present invention relates to a polycrystalline diamond compact. A method for manufacturing a polycrystalline diamond compact includes: preparing primary sintering by mixing and assembling first diamond particles and metal binder particles; sintering the mixed and assembled particles; leaching the upper surface of the sintered polycrystalline diamond compact; preparing secondary sintering by mixing second diamond particles and the metal binder particles and assembling the mixed particles on the upper surface of the primarily sintered polycrystalline diamond compact; sintering the sintered polycrystalline diamond compact and the mixed particles of the upper part; and a grinding step of grinding the reassembled second diamond particles and metal binder particles so as to remove the same. The polycrystalline diamond compact minimizes the content of the residual metal binder in a surface layer and increases the content of the diamond particles with high thermal conductivity, thereby increasing the lifespan of the polycrystalline diamond compact.

The present invention relates to a polycrystalline diamond compact. A method for manufacturing a polycrystalline diamond compact includes: preparing primary sintering by mixing and assembling first diamond particles and metal binder particles; sintering the mixed and assembled particles; leaching the upper surface of the sintered polycrystalline diamond compact; preparing secondary sintering by mixing second diamond particles and the metal binder particles and assembling the mixed particles on the upper surface of the primarily sintered polycrystalline diamond compact; sintering the sintered polycrystalline diamond compact and the mixed particles of the upper part; and a grinding step of grinding the reassembled second diamond particles and metal binder particles so as to remove the same. The polycrystalline diamond compact minimizes the content of the residual metal binder in a surface layer and increases the content of the diamond particles with high thermal conductivity, thereby increasing the lifespan of the polycrystalline diamond compact.

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.

The present disclosure relates to methods for enhanced demetalyzation of an ultrahard material, such as polycrystalline diamond (PCD) or cubic boron nitride (CBN), using a thiourea solution. The thiourea solution may contain thiourea and an acid, such as a Bronstead acid suitable for leaching. The thiourea may contain thiourea or a substituted thiourea, including tautomers thereof. The ultrahard material may be exposed to the thiourea solution for a time and under conditions sufficient to remove at least a desired amount of a metal, such as a catalyst used during formation of the PCD or CBN, from at least a portion of the ultrahard material.

An aluminum based composite material includes an aluminum parent phase and dispersions dispersed in the aluminum parent phase and formed such that a portion or all of additives react with aluminum in the aluminum parent phase, an average particle diameter of the dispersions is 20 nm or less, a content of the dispersions is 0.25% by mass or more and 0.72% by mass or less in terms of carbon amount, and an interval between the dispersions adjacent to each other is 210 nm or less.