A method is used to manufacture a tube having a hollow interior for housing an axle shaft. The tube is formed in a single machine having a fixed base and a single press structure movable toward the fixed base. The single machine includes first and second die assemblies coupled to the fixed base and first and second mandrels coupled to the single press structure. The method includes the steps of placing a billet into the first die assembly, pressing the billet into the first die assembly with the first mandrel to producing a pre-formed billet, and moving the pre-formed billet from the first die assembly to the second die assembly. THE method further includes the steps of pressing the pre-formed billet into the second die assembly with the second mandrel to elongate the pre-formed billet and form a hollow interior therein to produce an extruded tube.

A pipe extrusion includes a cross-section with a substantially round outer perimeter. A round portion of the substantially round outer perimeter preferably has an included angle of less than 300 degrees. A pair of inward facing flanges terminate the round portion. A cross member is formed across an inner area of the round portion. The cross member is parallel with the pair of inward facing flanges. A position of the cross member relative to a centerline of the round portion is between 0-20 degrees from the center line of the round portion. The pipe extrusion is preferably fabricated from any suitable aluminum alloy, such as T-6 aluminum.

Shear-assisted extrusion processes for forming extrusions of a desired composition from a feedstock material are provided. The processes can include applying a rotational shearing force and an axial extrusion to the same location on the feedstock material. Devices for this can include a die tool defined by a die face extending from a rim of the die face inwardly at an angle greater than zero in relation to a sidewall of the die tool in at least one cross section; and/or a die tool defining an opening configured to receive feedstock material for extrusion and further defining a die face defining a recess within the die face and contiguous with the opening. Shear-assisted extrusion processes are also provided that can mix different portions of the feedstock material within a recess about the opening prior to feedstock material entering the opening; and extruding the mixed portions.

A process to fabricate ultra-fine grain metal hollow object, comprising: inserting an annealed hollow prototype in an Equal Channel Angular Pressing (ECAP) die, providing a flexible elastic polyurethane mandrel to fill the central hollow space, optionally (if needed) provide polyurethane support to fill the spaces between the outer boundary of the prototype and the inner surface of the ECAP channel and to exert sufficient pressure to complete the ECAP process. The process is designed to improve thermal conductance and mechanical properties of hollow metal parts and is especially applicable to achieving the maximal heat conductance and tensile strength of titanium piping, construction tubing, and cylindrical reactors.

An extrusion apparatus and a method for manufacturing an aluminum capillary tube using the same are provided. The extrusion apparatus includes a container, a housing mold provided on one side of the container and including a plurality of dies formed with a plurality of holes, and a ram pressing an aluminum billet accommodated in the container in a direction from another side to the one side of the container so that the aluminum billet accommodated in the container is extruded into a plurality of aluminum capillary tubes having cross-sectional shapes corresponding to the plurality of holes, and the number of the plurality of holes is determined based on an inner diameter of the container and a diameter of each of the plurality of holes.

A friction assisted tube fabrication method is disclosed. The friction assisted tube fabrication includes a set of methods such as a friction assisted tube forming, a friction assisted tube extrusion, and a friction assisted tube straining method. A metal object, for example, a deformable tube is simply deformed into the tube using a mandrel. The metal object with an initial diameter is forced across the slope of the mandrel with an angle. The mandrel is configured to rotate while forcing the metal object to deform into the tube with the desired radius. While rotating the mandrel, a friction is generated due to contact between the tube and the mandrel, thereby generating thermal energy to heat a deformation area of the tube for simply and easily softening and forming into the desired shape with accuracy diameter, and dimensions using a nominal pressing force without additional equipment and power.

A method for manufacturing a cold-forged, extruded aluminum alloy tube includes the steps of: providing a primary material having a hollow columnar shape and made of an aluminum alloy material, and a first cold extrusion apparatus; processing the primary material to form a preform; subjecting the preform to a homogeneous annealing by heating to a temperature of about 410 C. to 510 C. and then cooling to a temperature of about 160 C. to 200 C.; testing the hardness of the preform; immersing the preform in a tank containing lubricant having a free total acidity concentration of 40 to 50 mg/L at a working temperature of 80 C. to 100 C.; and subjecting the preform to cold extrusion.

An extruded material includes a peripheral wall having a closed loop-shaped cross-section and defining a hollow, and a middle rib connected to an inner peripheral surface of the peripheral wall and dividing the hollow. The extruded material is provided with a corrected portion set at a predetermined portion in a longitudinal direction and subjected to correction processing, and an uncorrected portion not subjected to the correction processing. The peripheral wall is expanded outward with respect to an original shape of the uncorrected portion in the corrected portion. While the middle rib is curved with respect to an imaginary straight line connecting connecting portions connected with the peripheral wall at both end portions of the middle rib in the uncorrected portion, the middle rib has a smaller degree of curvature than the original shape of the uncorrected portion in the corrected portion.

If a mandrel for extruding metal pipes, having two axially offset pressing surfaces with different radial characteristics and having a transition region between these two pressing surfaces has a support surface in the transition region then the negative effect of narrowing, which arises owing to the mandrel shifting from a first pressing position, in which the first of the two pressing surfaces interacts with a die, to a second pressing position, in which the second pressing surface interacts with the die, can be minimized.

A process to fabricate ultra-fine grain metal hollow object, comprising: inserting an annealed hollow prototype in an Equal Channel Angular Pressing (ECAP) die, providing a flexible elastic polyurethane mandrel to fill the central hollow space, optionally (if needed) provide polyurethane support to fill the spaces between the outer boundary of the prototype and the inner surface of the ECAP channel and to exert sufficient pressure to complete the ECAP process. The process is designed to improve thermal conductance and mechanical properties of hollow metal parts and is especially applicable to achieving the maximal heat conductance and tensile strength of titanium piping, construction tubing, and cylindrical reactors.