A ratio of a total surface area of aluminum particles pressed into or adhering to a region having a predetermined surface area to the surface area of the region is less than or equal to 0.05%. The total surface area of crystallized products present in the region is less than or equal to 2% with respect to the surface area of the region. An average surface area per crystallized product is less than or equal to 2 ?m.sup.2. Surface roughness Ra of the region is less than 20 nm.

A method for forming a multilayer composite structure comprises providing a first sheet comprising a copper-comprising layer sandwiched by first and second graphene layers, wrapping the first sheet to form a first rod, and compacting the first rod to form a first multilayer composite structure.

A steel foil according to an aspect of the present invention includes a rolled steel foil; and a Ni having <111>//RD texture plated on an outermost layer of the rolled steel foil. Regarding the steel foil, a <111> pole density in an inverse pole figure of a rolling direction may be 3.0 or more and 6.0 or less.

An aluminum foil rolling process includes: providing first and second aluminum foils, each having first and second faces; lubricating one face between the first and second faces to obtain a first lubricated face; coupling the first and second foils, thereby obtaining a coupled foil having two outer faces; rolling the coupled foil, reducing the thickness of the coupled foil; lubricating one face between the two outer faces of the coupled foil, obtaining a coupled foil having a second lubricated face; winding the coupled foil having the second lubricated face, obtaining a wound coupled foil; partially separating the coupled foil by unwinding one of the first and second foils, obtaining a wound coupled foil; unwinding the wound coupled foil; rolling the coupled foil thereby obtaining a coupled foil with reduced thickness; separating the coupled foil with reduced thickness obtaining a first and second foils with respective first and second reduced thicknesses.

A dual-hardness clad steel plate. One surface of the steel plate is a high-hardness layer, the other surface of the steel plate is a low-hardness layer, and a combination of atoms is achieved between the high-hardness layer and the low-hardness layer by rolling bonding, wherein Mn13 steel is adopted for the low-hardness layer, and the Brinell hardness of the high-hardness layer is greater than 600. Further disclosed is a production method of the dual-hardness clad steel plate, comprising: 1) respectively preparing a high-hardness layer slab and a low-hardness layer slab; 2) assembling: preprocessing combined faces of the slabs, carrying out peripheral welded sealing on joint faces of the slabs, and carrying out vacuumizing treatment on a composite slab after welded sealing; 3) heating; 4) carrying out composite rolling; 5) cooling; and 6) carrying out thermal treatment, wherein the heating temperature is 1050-1100 C., the heating time is 2-3 min/mmslab thickness, and water cooling is performed on the heated slab, and the water temperature is lower than 40 C. The steel plate has different hardness characteristics and good low-temperature toughness

A method of manufacturing a strip for a bearing may comprise roll-bonding a bearing layer comprising a tin-free aluminium alloy directly to a base layer to form a bimetal and heat-treating the bimetal at a temperature below a recrystallization initiation temperature of the aluminium alloy. A strip for a bearing manufactured using the method, and a bearing having a strip manufactured using the method, are also provided.

Provided is a clad steel plate with excellent thermal conductivity that can be used suitably in cookware and the like. The present invention is a three-layer clad steel plate having a carbon steel base material and stainless steel mating material disposed respectively on both surface sides of the base material, wherein a plate thickness ratio L given by Equation (1) is 1.0-5.0 and at least one surface of the clad steel plate has a plurality of protrusions and recesses. Plate thickness ratio L=the plate thickness of the base material/the total thickness of the mating material . . . Equation (1) Here, the base material thickness and the mating material thickness are the thicknesses at the protrusions.

The present invention provides an isothermal processing method for making an isothermal processed copper clad aluminum composite comprising: providing an aluminum component and a copper component; cleaning the aluminum component and shape finishing the aluminum component; extruding the aluminum component into a core aluminum billet; cleaning the copper component; transforming the copper component into a copper cladding layer; cladding longitudinal and circumferential surfaces of the core aluminum billet with the copper cladding layer and molding the core aluminum billet and the copper cladding layer together to form a copper cladded aluminum billet; and transforming the copper cladded aluminum billet into an isothermal processed copper cladded aluminum composite through isothermal rolling and annealing. The present invention also provides an isothermal processed copper cladded aluminum composite and a system for manufacturing an isothermal processed copper cladded aluminum composite.

A method for producing a composite material, particularly a steel composite material, may involve providing a first workpiece and a second workpiece, producing a bonded connection between said first and said second workpiece in order to form a provisional composite, and rolling said provisional composite in order to form the composite material. During the rolling, the bonded connection may be at least partially released, in the form of a predetermined breaking point. The rolling may be performed as hot rolling. Further, the method may involve substantially hermetically sealing the provisional composite by way of a sealant. The first and second work pieces, moreover, may be peripherally connected by way of the bonded connection along an edge area of a contact surface formed by the first and second work pieces.

In a method for producing a component by hot forming of a pre-product made of steel, the pre-product is heated to forming temperature and subsequently formed. The product is heated to a temperature below the AC.sub.1-transformation temperature and undergoes a strength increase prior to the heating by cold forming.