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.

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.

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.

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.

The present invention discloses a forward and backward extrusion composite forming method using a mould having an open inner cavity, including the following steps: (1) the structural design and assembly of the forward and backward extrusion composite mould having the open inner cavity; (2) the preparation of the initial billet; and (3) forward and backward extrusion composite forming. The present invention can greatly improve the length-diameter ratio of the blind hole and is widely used in alloy steel, aluminum alloy, magnesium alloy, copper alloy and other components.

A hollow preform impact extruded from a metal billet to produce a progressing wall at a transition wall thickness. An axially forward portion of the progressing wall is ironed by extrusion past an extrusion point to form a sidewall portion of a lesser thickness. Extruding is stopped while some of the billet remains to form the closed bottom end. The preform has a bottom portion, a sidewall portion and a transition wall portion extending between the bottom portion and the sidewall portion. The transition wall portion is thicker than the sidewall portion and can be formed into at least part of the rim of an expansion shaped container. An impact extrusion punch has a central axis, an axially forward, impact surface for impacting metal to be extruded, a transition region for directing material displaced by the impact surface and a rear extrusion point for ironing material extruded past the transition region.

A hollow preform impact extruded from a metal billet to produce a progressing wall at a transition wall thickness. An axially forward portion of the progressing wall is ironed by extrusion past an extrusion point to form a sidewall portion of a lesser thickness. Extruding is stopped while some of the billet remains to form the closed bottom end. The preform has a bottom portion, a sidewall portion and a transition wall portion extending between the bottom portion and the sidewall portion. The transition wall portion is thicker than the sidewall portion and can be formed into at least part of the rim of an expansion shaped container. An impact extrusion punch has a central axis, an axially forward, impact surface for impacting metal to be extruded, a transition region for directing material displaced by the impact surface and a rear extrusion point for ironing material extruded past the transition region.

A special-purpose die for shaping an aluminum-magnesium alloy by rotating extrusion is provided, including a male die and a female die, wherein a trapezoidally-sectioned groove is formed at an end portion of a working area of the male die, an inner portion of the male die is hollow, with the hollow inner portion having sections of equal area, a circumferential wall of a die cavity of the female die is provided with at least two symmetrical axial grooves, and a cavity is formed inside a clamping part of the female die. The present disclosure remarkably reduces the axial extrusion force such that the deformation of the formed workpiece is more uniform, which greatly improves the mechanical property of the formed workpiece.

A special-purpose die for shaping an aluminum-magnesium alloy by rotating extrusion is provided, including a male die and a female die, wherein a trapezoidally-sectioned groove is formed at an end portion of a working area of the male die, an inner portion of the male die is hollow, with the hollow inner portion having sections of equal area, a circumferential wall of a die cavity of the female die is provided with at least two symmetrical axial grooves, and a cavity is formed inside a clamping part of the female die. The present disclosure remarkably reduces the axial extrusion force such that the deformation of the formed workpiece is more uniform, which greatly improves the mechanical property of the formed workpiece.

An extrusion die includes: a cylindrical mandrel, the mandrel having a circumferential groove formed therein; a cylindrical die plate, the mandrel and the die plate being coupled together; and a shrink ring disposed in the circumferential groove of the mandrel.