A component of a downhole tool utilized in oil and natural gas exploration and production comprises inorganic hydrolysable compound-containing materials. The inorganic hydrolysable compounds grant the component the degradability/dissolution in aqueous environment. The inorganic hydrolysable compounds include, but not are limited to, hydrolysable carbides, nitrides, and sulfides, such as aluminum carbide (Al.sub.4C.sub.3), calcium carbide (CaC.sub.2), magnesium carbide (Mg.sub.2C.sub.3 or MgC.sub.2), manganese carbide (Mn.sub.3C), aluminum nitride (AlN), calcium nitride (Ca.sub.3N.sub.2), magnesium nitride (Mg.sub.3N.sub.2), aluminum sulfide (Al.sub.2S.sub.3), aluminum magnesium carbide (Al.sub.dMgC.sub.2), and aluminum zinc carbide (Al.sub.4Zn.sub.2C.sub.3).

A thixomolding material includes: a metal body that contains Mg as a main component; and a coating portion that is adhered to a surface of the metal body via a binder and contains SiC particles containing SiC as a main component. A mass fraction of the SiC particles in a total mass of the metal body and the SiC particles is 2.0 mass % or more and 40.0 mass % or less. The binder may contain waxes. A content of the binder may be 0.001 mass % or more and 0.200 mass % or less.

A composite material comprising a plurality of round particles bound together by a binding material. Each of the plurality of round particles includes a wear resistant element, an intermediate coating on the wear resistant element, and a round outer layer encapsulating the intermediate coating and the wear resistant element. The intermediate coating is metallurgically bonded to the wear resistant element, and is metallurgically bondable to the binding material.

A composite material comprising a plurality of round particles bound together by a binding material. Each of the plurality of round particles includes a wear resistant element, an intermediate coating on the wear resistant element, and a round outer layer encapsulating the intermediate coating and the wear resistant element. The intermediate coating is metallurgically bonded to the wear resistant element, and is metallurgically bondable to the binding material.

An oxygen solid solution titanium sintered compact includes a matrix made of a titanium component having an α-phase, oxygen atoms dissolved as a solute of solid solution in a crystal lattice of the titanium component, and metal atoms dissolved as a solute of solid solution in the crystal lattice of the titanium component.

Some variations provide an additively manufactured aluminum alloy comprising from 84.5 wt % to 92.1 wt % aluminum; from 1.1 wt % to 2.1 wt % copper; from 1.8 wt % to 2.9 wt % magnesium; from 4.5 wt % to 6.1 wt % zinc; and from 0.5 wt % to 2.8 wt % zirconium. The additively manufactured aluminum alloy is in the form of a three-dimensional component. The zirconium functions as a grain-refiner element within the additively manufactured aluminum alloy. The additively manufactured aluminum alloy may be characterized by an average grain size of less than 10 microns. The additively manufactured aluminum alloy may have a substantially crack-free microstructure with equiaxed grains.

Some variations provide an additively manufactured aluminum alloy comprising from 84.5 wt % to 92.1 wt % aluminum; from 1.1 wt % to 2.1 wt % copper; from 1.8 wt % to 2.9 wt % magnesium; from 4.5 wt % to 6.1 wt % zinc; and from 0.5 wt % to 2.8 wt % zirconium. The additively manufactured aluminum alloy is in the form of a three-dimensional component. The zirconium functions as a grain-refiner element within the additively manufactured aluminum alloy. The additively manufactured aluminum alloy may be characterized by an average grain size of less than 10 microns. The additively manufactured aluminum alloy may have a substantially crack-free microstructure with equiaxed grains.

A DC motor is provided that can suppress a commutator from wearing. A DC motor including a commutator formed of copper or a copper alloy of 99% or more copper, and a brush pressed against and in contact with the commutator, wherein the brush is composed of a sintered compact including graphite and copper powder, hard compound particles higher in hardness than any of the copper or the copper alloy and the graphite or the copper powder are contained in at least one of the commutator and the brush and are scattered on or near a contact surface of the commutator with the brush at least during use.

A method may include controlling, by a computing device, an energy source to form a melt pool at a build surface; and controlling, by the computing device, a material delivery device to direct a powder at the melt pool to form the seal fin comprising a metal matrix composite on the build surface, wherein the metal matrix composite comprises a matrix material and a reinforcement phase.

The present invention provides a powder for forming a black light-shielding film having a specific surface area of 20 to 90 m.sup.2/g, which is measured by the BET method, comprising zirconium nitride as a main component, and containing magnesium and/or aluminum. If containing the magnesium, the content of the magnesium is 0.01 to 1.0% by mass relative to 100% by mass of the powder for forming a black light-shielding film, and if containing the aluminum, the content of the aluminum is 0.01 to 1.0% by mass relative to 100% by mass of the powder for forming the black light-shielding film.