A composite tube manufacturing method includes the following steps: providing a billet, wherein the billet includes an inner material and an outer material, and the inner material is enveloped in the outer material; heating the billet; pushing the billet to a to-be-extruded position; and performing an extrusion process, and extruding the billet to a composite tube, wherein the inner material and the outer material of the billet are respectively extruded to an inner tube and an outer tube of the composite tube, and the outer tube is bonded to the inner tube through the extrusion process.

A composite tube manufacturing method includes the following steps: providing a billet, wherein the billet includes an inner material and an outer material, and the inner material is enveloped in the outer material; heating the billet; pushing the billet to a to-be-extruded position; and performing an extrusion process, and extruding the billet to a composite tube, wherein the inner material and the outer material of the billet are respectively extruded to an inner tube and an outer tube of the composite tube, and the outer tube is bonded to the inner tube through the extrusion process.

Provided is a method of forming a cup-shaped aluminum-magnesium-alloy article by rotary extrusion, including the following steps. (1) Blanking. (2) Performing rotary extrusion: placing a cylindrical billet into a concave die cavity, wherein a peripheral wall of the cavity of the concave die is provided with at least two symmetrical axial grooves; inserting a convex die into the concave die cavity, wherein an end of a working region of the convex die is provided with a groove of a trapezoidal cross section; subjecting the convex die to forward extrusion and heating, and simultaneously rotating and heating the concave die, wherein an integral torque is formed during the extrusion process of the convex die by using the cylindrical billet inside the groove having a trapezoidal cross section, and wherein a synchronized rotation with the concave die is achieved by using a metallic billet that flows into the axial groove. (3) Demolding.

Provided is a method of forming a cup-shaped aluminum-magnesium-alloy article by rotary extrusion, including the following steps. (1) Blanking. (2) Performing rotary extrusion: placing a cylindrical billet into a concave die cavity, wherein a peripheral wall of the cavity of the concave die is provided with at least two symmetrical axial grooves; inserting a convex die into the concave die cavity, wherein an end of a working region of the convex die is provided with a groove of a trapezoidal cross section; subjecting the convex die to forward extrusion and heating, and simultaneously rotating and heating the concave die, wherein an integral torque is formed during the extrusion process of the convex die by using the cylindrical billet inside the groove having a trapezoidal cross section, and wherein a synchronized rotation with the concave die is achieved by using a metallic billet that flows into the axial groove. (3) Demolding.

The present invention discloses a rotary extrusion producing mold for producing an inner ring rib with a large aspect ratio formed of a hollow billet, which consists of a concave die, a left half convex die, a right half convex die, a mandrel, a lower core support and an elastic supporting mechanism, the left and right half convex dies are fixed onto an upper template connected with a slider and a horizontal hydraulic cylinder, a left drive hydraulic cylinder and a right drive hydraulic cylinder are mounted at both ends of the upper template, respectively, the lower core support passes through a middle of the concave die, the elastic supporting mechanism is mounted at a bottom of the lower core support, a drive gear is mounted on a side face of the concave die, and the mandrel is disposed between the left and right half convex dies.

The present invention discloses a rotary extrusion producing mold for producing an inner ring rib with a large aspect ratio formed of a hollow billet, which consists of a concave die, a left half convex die, a right half convex die, a mandrel, a lower core support and an elastic supporting mechanism, the left and right half convex dies are fixed onto an upper template connected with a slider and a horizontal hydraulic cylinder, a left drive hydraulic cylinder and a right drive hydraulic cylinder are mounted at both ends of the upper template, respectively, the lower core support passes through a middle of the concave die, the elastic supporting mechanism is mounted at a bottom of the lower core support, a drive gear is mounted on a side face of the concave die, and the mandrel is disposed between the left and right half convex dies.

The present invention discloses a rotary extrusion producing method for producing an inner ring rib with a large aspect ratio formed of a hollow billet, which includes: combining, at an initial stage of rotary extrusion, two convex dies together and driving, by a slider on a press machine, left and right half convex dies to extrude a blank downward to form an initial profile of a transverse rib; dragging respectively, by left and right horizontal hydraulic cylinders, the left and right half convex dies to move in a radial direction, to form an initial cylindrical wall, so as to achieve a purpose of forming the transverse rib, once the blank is extruded downward by a certain depth, where a head of a mandrel is set to be at a certain conical degree, and a certain number of processed pits are distributed on an inner cavity of a concave die.

A method is used to manufacture a drawn tube having a hollow low interior for housing an axle shaft. The method includes the steps of placing a billet into a first die assembly and pressing the billet into the first die to producing a pre-formed billet. The method also includes the steps of moving the pre-formed billet from the first die assembly to a second die assembly and pressing the pre-formed billet into the second die assembly to produce an extruded tube. The method further includes the steps of moving the extruded tube from the second die assembly to a third die assembly and pressing the extruded tube into the third die assembly to further elongate the extruded tube and decrease the thickness of the wall of the extruded tube to of from about 3 to about 18 millimeters to produce the drawn tube having the yield strength of at least 750 MPa.

In extrusion processing in which diameter reduction is performed by pressing a raw pipe having a core bar inserted therein into a die having a small inner diameter portion on its tip end side, a differential thickness pipe having a thick-walled portion at its tip end can be molded using a core bar having a small cross-section portion formed at its tip end. It is also possible to mold a differential thickness pipe having a thick-walled part at an intermediate axial position by using a raw pipe having a thin-walled portion at its tip end. For example, such a raw pipe can be molded by extrusion processing using a core bar having no small cross section portion at its tip end, prior to the above-described formation of the thick-walled portion. When higher dimensional accuracy is required, a so-called counter punch may be used in the formation of the thick-walled portion.

In extrusion processing in which diameter reduction is performed by pressing a raw pipe having a core bar inserted therein into a die having a small inner diameter portion on its tip end side, a differential thickness pipe having a thick-walled portion at its tip end can be molded using a core bar having a small cross-section portion formed at its tip end. It is also possible to mold a differential thickness pipe having a thick-walled part at an intermediate axial position by using a raw pipe having a thin-walled portion at its tip end. For example, such a raw pipe can be molded by extrusion processing using a core bar having no small cross section portion at its tip end, prior to the above-described formation of the thick-walled portion. When higher dimensional accuracy is required, a so-called counter punch may be used in the formation of the thick-walled portion.