Provided is aluminum (Al) alloy foam including an Al alloy matrix containing magnesium (Mg), and hollow ceramic spheres dispersed in the Al alloy matrix, wherein a reaction layer including a MgAl composite oxide is formed at an interface where the Al alloy matrix is in contact with the hollow ceramic spheres, and wherein a density of the Al alloy foam may be higher at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

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

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.

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 m 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 metal-ceramic composite material and a method for forming the same are provided. The metal-ceramic composite material includes a metal body, a plurality of metal oxide nanoparticles and a plurality of ceramic particles. The metal body includes a metal material having a first surface energy. The metal oxide nanoparticles and the ceramic particles are dispersed in the metal body. The ceramic particles have a second surface energy that is higher than the first surface energy.

Provided is aluminum (Al) alloy foam including an Al alloy matrix containing magnesium (Mg), and hollow ceramic spheres dispersed in the Al alloy matrix, wherein a reaction layer including a MgAl composite oxide is formed at an interface where the Al alloy matrix is in contact with the hollow ceramic spheres, and wherein a density of the Al alloy foam may be higher at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

Provided is aluminum (Al) alloy foam including an Al alloy matrix containing magnesium (Mg), and hollow ceramic spheres dispersed in the Al alloy matrix, wherein a reaction layer including a MgAl composite oxide is formed at an interface where the Al alloy matrix is in contact with the hollow ceramic spheres, and wherein a density of the Al alloy foam may be higher at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

A metal matrix composite tool includes a body having hard composite portion that includes reinforcing particles dispersed in a binder material. At least some of the reinforcing particles comprise a monolithic particle structure including a core having irregular outer surface features integral with the core.

A metal matrix composite tool includes a body having hard composite portion that includes reinforcing particles dispersed in a binder material. At least some of the reinforcing particles comprise a monolithic particle structure including a core having irregular outer surface features integral with the core.

A method, performed by a centrifuge, for treating toughness and hardness of drill bit buttons is provided. The centrifuge comprises a chamber formed by a stationary side wall and a bottom which is rotatable around a rotation axis, the bottom comprising one or more protrusions which at least partly extends between the rotation axis and the side wall, the side wall comprising at least six pushing elements arranged around a periphery of the side wall. The method comprises rotating, by rotation of the bottom with the protrusions, the drill bit buttons around the rotation axis, pushing, by the pushing elements, the drill bit buttons from the side wall during the rotation of the bottom, collectively forming the drill bit buttons into a torus shape at the bottom of the chamber for inducing collisions between the drill bit buttons, thereby treating the toughness and hardness of the drill bit.