The invention is directed to the interventionless activation of wellbore devices using dissolving and/or degrading and/or expanding structural materials. Engineered response materials, such as those that dissolve and/or degrade or expand upon exposure to specific environment, can be used to centralize a device in a wellbore.

A method for manufacturing a high-performance NdFeB rare earth permanent magnetic device which is made of an RFeCoB-M strip casting alloy, a micro-crystal HRFe alloy fiber, and T.sub.mG.sub.n compound micro-powder, includes steps of: manufacturing the RFeCoB-M strip casting alloy, manufacturing the micro-crystal HRFe alloy fiber, providing hydrogen decrepitating, pre-mixing, powdering with jet milling, post-mixing, providing magnetic field pressing, sintering and ageing, wherein after a sintered NdFeB permanent magnet is manufactured, machining and surface-treating the sintered NdFeB permanent magnet for forming a rare earth permanent device.

A method for manufacturing a high-performance NdFeB rare earth permanent magnetic device which is made of an RFeCoB-M strip casting alloy, a micro-crystal HRFe alloy fiber, and T.sub.mG.sub.n compound micro-powder, includes steps of: manufacturing the RFeCoB-M strip casting alloy, manufacturing the micro-crystal HRFe alloy fiber, providing hydrogen decrepitating, pre-mixing, powdering with jet milling, post-mixing, providing magnetic field pressing, sintering and ageing, wherein after a sintered NdFeB permanent magnet is manufactured, machining and surface-treating the sintered NdFeB permanent magnet for forming a rare earth permanent device.

A titanium alloy member with high strength and high proof stress not only in the surface but also inside, using a general and inexpensive - type titanium alloy, and a production method therefor, are provided. The production method includes preparing a raw material made of titanium alloy, nitriding the raw material to form a nitrogen-containing raw material by generating a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the raw material, mixing the raw material and the nitrogen-containing raw material to yield a nitrogen-containing mixed material, sintering the nitrogen-containing mixed material to obtain a sintered titanium alloy member by bonding the material together and uniformly diffusing nitrogen in solid solution from the nitrogen-containing raw material to the entire interior portion of the sintered titanium alloy member, and hot plastic forming the sintered titanium alloy member.

A titanium alloy member with high strength and high proof stress not only in the surface but also inside, using a general and inexpensive - type titanium alloy, and a production method therefor, are provided. The production method includes preparing a raw material made of titanium alloy, nitriding the raw material to form a nitrogen-containing raw material by generating a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the raw material, mixing the raw material and the nitrogen-containing raw material to yield a nitrogen-containing mixed material, sintering the nitrogen-containing mixed material to obtain a sintered titanium alloy member by bonding the material together and uniformly diffusing nitrogen in solid solution from the nitrogen-containing raw material to the entire interior portion of the sintered titanium alloy member, and hot plastic forming the sintered titanium alloy member.

A friction material, such as those belonging to the NAO or LS classes. The friction material is substantially free from copper and includes non-spherical particles in the form of powders and/or fibres each constituted by a preferably ferrous metallic core and by an at least partial coating of core formed at least partially or totally by tin and/or tin compounds, such as intermetallic FeSn compounds.

A friction material, such as those belonging to the NAO or LS classes. The friction material is substantially free from copper and includes non-spherical particles in the form of powders and/or fibres each constituted by a preferably ferrous metallic core and by an at least partial coating of core formed at least partially or totally by tin and/or tin compounds, such as intermetallic FeSn compounds.

Provided is a copper powder that has an increased number of points of contact between copper powder particles, that ensures excellent conductivity, and that can be suitably used in a conductive paste, an electromagnetic wave shield, or the like. The copper powder is configured from flat plate-shaped copper particles that form a dendritic shape having a linearly grown main trunk and a plurality of branches branching from the main trunk. The main trunk and the branches have an average cross-sectional thickness of more than 1.0 m but no more than 5.0 m. The copper powder has a flat plate shape that is configured from a layered structure of one layer or a plurality of stacked layers. The average particle size (D50) is 1.0-100 m.

Provided is a copper powder that has an increased number of points of contact between copper powder particles, that ensures excellent conductivity, and that can be suitably used in a conductive paste, an electromagnetic wave shield, or the like. The copper powder is configured from flat plate-shaped copper particles that form a dendritic shape having a linearly grown main trunk and a plurality of branches branching from the main trunk. The main trunk and the branches have an average cross-sectional thickness of more than 1.0 m but no more than 5.0 m. The copper powder has a flat plate shape that is configured from a layered structure of one layer or a plurality of stacked layers. The average particle size (D50) is 1.0-100 m.

A friction material, such as those belonging to the NAO or LS classes. The friction material is substantially free from copper and includes non-spherical particles in the form of powders and/or fibers each constituted by a preferably ferrous metallic core and by an at least partial coating of core formed at least partially or totally by tin and/or tin compounds, such as intermetallic FeSn compounds.