Composite tube assemblies and thin-walled tubing are disclosed. In embodiments, the composite tube assemblies include a functional tube and a sacrificial tube disposed within or around the functional tube. The sacrificial tube may be removed by exposure to a corrosive media, without substantially affecting the functional tube. Methods of forming composite tube assemblies and thin-walled tubing are also described.

A cylindrical body includes a cylindrical member, made by forming a metal plate into a cylindrical shape such that the two end faces of the metal plate face each other, and a nonmetallic adhesive member bonding the two end faces together. The two end faces each include an adhesive part, and the adhesive member is disposed between the adhesive parts of the end faces. The adhesive part of one end face is not parallel to the adhesive part of the other end face. Each end face also includes a contact part which is in contact with the contact part of the other end face.

Shear-assisted extrusion assemblies are provided. The assemblies can include a billet containing assembly containing a billet comprising a billet outer material and a billet inner material in at least one cross-section; a tool operably engaged with the billet; an extrudate receiving channel configured to receive extrudate from the tool, wherein the extrudate comprises extruded outer material and extruded inner material in at least one cross-section, the extruded outer material being the same material as the billet outer material, and the extruded inner material being the same as the billet inner material. Methods for producing multi-material shear-assisted extrudate are also provided.

Methods described herein can include drawing materials to form a drawn filled tubing (DFT) wire. The materials can include a core material, a first layer of a biocompatible material disposed exterior to the filler material, a magnetic material disposed external to the first layer of biocompatible material, and a second layer of biocompatible material disposed exterior to the magnetic material. In some embodiments, the method further comprises melting the core material to form a magnet with a through hole lumen. In some embodiments, the method can further include applying an external magnetic field to the materials during the drawing to align grains of the magnetic material. In some embodiments, the core material can have a melting point lower than a melting point of the magnetic material and the biocompatible material.

A finned tube having a tube main body, on the outside of which, in particular separate or integral, fins are arranged, preferably circumferentially, wherein the fins and/or the tube main body are of a multi-layer material.

A connection tube (1) for connecting two tubes (8, 9) of different alloys, wherein the connection tube has a central through-hole extending along a longitudinal axis and comprises a first end portion (2) of a first alloy, a second end portion (3) of a second alloy, and a middle portion (4) which is at least partly double-layered with said second alloy forming an annular inner layer and said first alloy forming an annular outer layer, wherein a metallic bond has been formed between said layers. The inner and outer layers are mechanically interlocked by means of at least one helically extending thread formed in an interface between said layers. The connection tube is manufactured from a base component and an outer component threaded onto the base component to form a work piece, which is hot worked to form a metallic bond.

A method of making mechanically-lined pipe with primary expansion by plastically expanding a liner sleeve within an outer pipe, under lining pressure applied internally to the liner sleeve. On relieving the lining pressure, elastic radial contraction of the outer pipe makes a mechanical bond between the outer pipe and the liner sleeve. Then, secondary expansion of the outer pipe is performed under fixing pressure, which may be greater than the lining pressure, applied internally to the liner sleeve at an end portion of the pipe. This makes or strengthens a mechanical bond at the end portion. The resulting pipe joint has an end portion and a body portion inboard of the end portion. The body portion has a first, lesser bonding pressure between the outer pipe and the liner sleeve. The end portion has a second, greater bonding pressure between the outer pipe and liner sleeve.

A method of manufacturing a rectangular tube having a stepped portion includes: forming V-shaped grooves on a rectangular tube at surfaces of an end thereof in a direction parallel to a longitudinal direction thereof; and pressing each of the surfaces having the V-shaped grooves formed thereon with a rotating roll from outside to inside, whereby the end of the rectangular tube is radially reduced.

An apparatus for manufacturing a multi-layer pipe is provided. The apparatus includes a ram extruding a matrix pipe, which is formed by inserting one or more insert pipes having different diameters into a receiving pipe, with a constant compression force, a heat-treatment unit heat-treating the matrix pipe extruded from the ram, and a drawing unit drawing, with a constant drawing force, the matrix pipe passing through the heat-treatment unit into a multi-layer pipe having a predefined diameter.

A method for preparing a multilayer metal composite pipe includes steps of: internally and externally grinding blank pipes; cleaning oil stains; assembling a multilayer metal pipe; drawing to reduce a diameter; performing high-speed friction welding at the pipe ends; performing heat treatment; performing four-roller cross-rolling; straightening; performing two-roller cold-rolling; performing cold-drawing to reduce the diameter; performing cold-expansion to reduce the diameter; performing precise cold-rolling; degreasing; brightening; performing surface grinding; cleaning dust; detecting multilayer metal interface bonding; detecting flaws; testing metal structure performance; and sizing and packaging. By cycling the cold-drawing, the cold-expansion, and the precision cold-rolling, key indicators such as product dimensional accuracy, surface quality, material properties, and crystal grain size can be collaboratively controlled, so as to achieve higher accuracy, better performance, and more outstanding extreme specifications. The present invention solves the problem of inconsistent extension due to differences in metal properties.