中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 20 No. 5 May 2010 |
prepared by solid-state recycling process from chips
（1. School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China;
2. School of Materials Science and Engineering, Jiamusi University, Jiamusi 154007, China）
Abstract:AZ31B magnesium alloy chips were recycled by three solid-state recycling processes including cold-pressing, hot-pressing followed by hot extrusion and double extrusion. Microstructure and mechanical properties of the recycled specimens and reference specimens were compared. For the recycled specimen by cold-pressing, the grains are refined to a large extent during hot extrusion due to the presence of twins and high density dislocation. The recycled specimens by hot-pressing and double extrusion do not exhibit finer grain than that the recycled specimen by cold-pressing. Consequently, higher ultimate tensile strength of the recycled specimen by hot-pressing and double extrusion is not achieved. For hot pressing process, more compact billet lowers the porosity in recycled material, so elongation to failure of the recycled specimen increases. The recycled specimen fabricated by double extrusion process shows slightly higher elongation than the reference specimen. The second extrusion makes the oxides further crush and distribute more dispersedly, and minimizes porosity, which is responsible for the improved ductility.
Key words: AZ31B magnesium alloy; solid-state recycling; cold-pressing; hot-pressing; double extrusion
