Method for producing flat products made of aluminum alloys

Abstract

A method of producing flat products in aluminum alloys comprising:

• • A) cold rolling to a hardened condition:
  • B) applying a short-time ion beam surface treatment; and
  • C) repeating steps A and B until a flat rolled product of a specified thickness is obtained.

The surface treatment is preferably performed using an ion beam of atomic mass A≧10 amu having a power of between about 20-40 keV and an ion current density of between about 0.1-1 mA/cm² for from about 5 to about 200 seconds. In the process of irradiation flat products may be continuously and uniformly displaced with respect to the ion beam.

Description

FIELD OF THE INVENTION[0001]The present invention is related to aluminum metallurgy, and more particularly to a novel method for alleviating the hardened (cold worked) condition that requires stress relieving and structure improvement during conventional processing.BACKGROUND OF THE INVENTION [0002]The role of aluminum alloys as structural materials is constantly increasing. In addition to commercial pressures to improve the physical properties of aluminum alloys, recent adverse economic conditions have imposed additional pressures on reducing production costs.[0003]One of the most labor intensive and power consuming operations in the manufacture of flat rolled aluminum alloys are those operations related to the necessity to relieve the hardened (cold worked) condition originating in the course of cold rolling. Hardening or cold working in this context describes a condition wherein flat rolled aluminum hardens in the course of cold rolling. This hardening results in ductility reduct...

AI Technical Summary

Benefits of technology

[0016]It is therefore an object of the present invention to provide a method for annealing or relieving cold work in the course of processing aluminum flat rolled or otherwise processed products that eliminates the costly thermal annealing steps of the prior art.

Problems solved by technology

In addition to commercial pressures to improve the physical properties of aluminum alloys, recent adverse economic conditions have imposed additional pressures on reducing production costs.

One of the most labor intensive and power consuming operations in the manufacture of flat rolled aluminum alloys are those operations related to the necessity to relieve the hardened (cold worked) condition originating in the course of cold rolling.

This hardening results in ductility reduction that makes further rolling impossible.

Such handling results in the consumption of large amounts of time and power consumption that translate into high costs of production.

One of the most labor intensive steps during performance of these annealing operations is the removal of rolled coils from the hot rolling mill, coil transportation and placement into and removal from the annealing furnaces.

The obvious disadvantages of this method are the high labor cost and energy intensiveness of the process.

Another less apparent disadvantage relates to the impossibility eliminating some intermetallic compounds that originate in the course of annealing, for example the formation of Al6 (Fe, Mn).

The existence of coarse intermetallic compounds such as Al6 (Fe, Mn) in the alloy structure negatively influences the properties of the cold rolled material, in particular, it reduces its ductility.

All of these steps incur expenditures of time, labor, and electric power.

In the course of this prior art process the hardened condition is relieved only in the face-hardened zone, and it is also impossible to eliminate the formation of some intermetallic compounds such as, Al6(Fe, Mn) in the application of this prior art process to more conventional aluminum alloys.