Rotary swaging preparation method for high-strength magnesium alloy wire

Abstract

The invention relates to a rotary swaging preparation method for a high-strength magnesium alloy wire, and belongs to the technical field of nonferrous metal plastic molding. The method comprises the following steps: carrying out heat preservation on magnesium alloy bars for 1 to 15 minutes at the temperature of between 120 DEG C and 200 DEG C, and clamping the bars by a special fixture of a rotary swaging machine to carry out rotary swaging; and after the rotary swaging is finished, replacing a rotary swaging mold with smaller bore diameter to repeat the steps until the magnesium alloy wire with required diameter is obtained, wherein in the process of rotary swaging, the feeding speed is controlled to between 6 and 10m / min; the pass compression ratio is controlled to between 18 and 45 percent; and the coning angle of the rotary swaging mold is controlled to between10 and 26 degrees. The method uses the three-dimensional compressive stress state and the pulse loading mode provided by the rotary swaging to realize plastic-deformation induced dispersion-strengthening phase precipitation and grain refinement so as to fulfill the aim of improving mechanical properties. The prepared magnesium alloy has excellent performance, the yield strength thereof is 25 to 53 percent higher than that of the magnesium alloy wire prepared through extrusion, and the tensile strength thereof is 18 to 23 percent higher than that of the magnesium alloy wire prepared through extrusion. The method has the advantages of no need of special on-line insulating device, simple equipment, high production efficiency and easy operation.

Description

technical field [0001] The invention belongs to the technical field of plastic forming of non-ferrous metals, and in particular relates to a swaging preparation method of high-strength magnesium alloy wire. Background technique [0002] High-performance magnesium alloy wire can be used as welding wire, fiber-reinforced components, spectacle frames, special spring parts, aviation parts, etc., and is an ideal raw material for semi-solid thixoforming, with excellent market application prospects. At present, magnesium alloy wire is mainly produced by casting or plastic deformation. However, in order to prevent oxidation and combustion, the casting of magnesium alloy wire needs to be carried out under the condition of isolating oxygen (ZL200510043102.2), and the equipment is complicated; and the mechanical properties of cast magnesium alloy wire are much lower than those prepared by plastic deformation. However, due to the close-packed hexagonal crystal structure of magnesium al...

AI Technical Summary

Problems solved by technology

However, in order to prevent oxidation and combustion when casting magnesium alloy wire, it needs to be carried out under the condition of isolating oxygen (ZL200510043102.2), and the equipment is complicated; and the mechanical properties of cast magnesium alloy wire are much lower than those prepared by plastic deformation.

However, due to the close-packed hexagonal crystal structure of magnesium alloy, the plastic deformation ability at room temperature is poor, and thermal cracking is prone to occur in high temperature deformation, and the plastic deformation temperature range is narrow. The plastic forming process of magnesium alloy wire reported so far requires the design of a special mold insulation device to achieve deformation. On-line insulation of process billets (ZL200510042990.6, ZL200710036341.4, ZL200710071787.0, ZL200310119199, ZL03111456.3), complex equipment and high cost

In addition, when the magnesium alloy is deformed, the grain coarsening and surface thermal cracking tend to be serious due to friction and heat generated by plastic deformation, which limits the increase of the strain rate and the production efficiency is low.

Moreover, in the plastic forming preparation methods of magnesium alloy wire in the above patents, due to the high deformation temperature and low speed, the strength is low, which cannot fully meet the needs of welding wire and other aspects.

Therefore, for a long time, magnesium alloy wire cannot be used in large-scale commercial production due to reasons such as high production cost, low yield, and low production efficiency.