Advanced Powder Metallurgy Light Metals by Metal Working

作者：Kondoh Katsuyoshi^*; Kaneko Kantarou; Akita Toru

来源：Steel Research International, 2010, 81(9): 1283-1287.

• Magnesium alloy powder
• Roll compaction
• Grain refinement
• Orientation
• Extrusion
• Dynamic recrystallization

A roll compaction (RCP) process, consisting of the twin rolling and cutter milling equipments, has been developed to prepare coarse magnesium alloy powders with refined microstructures and randomized orientations by repetitively applying severe plastic deformation. The warm RCP process at 473 K was more effective to refine Mg grains and Mg17Al12 intermetallic compounds of AM60 alloy powders. In particular, in-situ precipitation of Mg17Al12 phases drastically progressed with increase in the repetition number of cycles in the RCP process, and their mean size was about 200-400 nm. Such refined compounds were uniformly distributed in the matrix, and useful to obstruct the grain coarsening by their pinning effect during hot extrusion. As a result, the fine grains of 1-2 mu m were formed when the warm RCP process at 473 K with 50 cycles was employed. Furthermore, the orientations of not only (0001) basal but also (10-10) nonbasal planes are remarkably randomized even after hot extrusion with increasing the repetition number of RCP process. The RCP process was successful for the fabrication of wrought AM60 powder alloys with a good balance of 360 MPa YS and elongation of 20% or more at room temperature.

• 出版日期2010-9