Continuous equal channel angular pressing

A method for continuously extruding metal, comprising:

• feeding a solid metal workpiece into one end of a passageway formed between a wheel member having an endless groove and a stationary constraint die that surrounds the wheel member and covers some of the length of the groove,
• the wheel member having a greater surface area for engaging the metal workpiece than the stationary constraint die,
• the passageway having a closed end remote from said one end and having a outlet through said stationary constraint die at said closed end, the passageway and outlet having substantially the same rectangular cross section.
• and moving the wheel member relative to the stationary constraint die in a direction towards the outlet from said one end to said closed end such that the frictional drag of the passageway defining surfaces of the second member drags the metal workpiece through the passageway and through the outlet.

An apparatus comprising:

• a first wheel member having an endless circumferential groove therein,
• a shoe member covering only part of the length of the groove and forming an input orifice with the groove and a passageway with the groove, the passageway having a rectangular cross section, the input orifice comprising an orifice for feeding a solid metal workpiece to be extruded into a portion of the passageway remote from the abutment member, the first wheel member having a greater surface area for engaging the metal workpiece than the shoe member,
• an abutment member projecting from the shoe member into the groove and blocking one end of the passageway,
• the first wheel member being rotatable relative to the shoe member in the direction toward the abutment member, the output orifice having substantially the same cross section as the cross section of the passageway
• an output orifice in the shoe member adjacent the abutment member, and
• a second rotatable wheel member remote from the abutment member of the shoe, the second rotatable wheel member configured to contact a side of the workpiece and urge the workpiece into the passageway such that the workpiece is carried in the groove by frictional drag in the direction towards the abutment member and is thereby extruded through the output orifice and without any substantial change in cross section.