AZ61镁合金连续流变挤压成形

采用自行设计的连续流变挤压成形技术,成功地制备出了10 mm的AZ61镁合金线材.在轧辊和靴子的搓动剪切作用下,形成了细小的等轴晶和球形晶,在挤压成形过程中,中心部位固相变形小,边部固相变形大,在圆弧流动区产生了优良的超细晶组织.浇注温度影响AZ61合金的固相率,进而对成形过程产生重要影响,合理的浇注温度为680℃.在此温度下,制备的AZ61合金线材断面组织优良,呈现两相塑性流动的特征.

Continuous Rheo-Extrusion of AZ61 Magnesium Alloy

A continuous rheo-extruding process was developed to prepare successfully the AZ61 alloy wire with diameter up to φ10 mm. Under the actions of kneading and shearing by roller and fixed shoe, the fine, spherical and equiaxed grains form from liquid alloy. In the extruding forming process, the deformation of solid phase in the central part is small, while the edgewise deformation is big, then the ultra-fine grain microstructure comes in the arc flowing part. Casting temperature can affect solid fraction and further exert a great influence on the forming process, and the appropriate casting temperature is 680°C. The cross-sectional microstructures of the AZ61 alloy wire prepared is favorable and shows the characteristic of two-phase plastic flow.