AZ31マグネシウム合金押出パイプの曲げ加工性に及ぼすMn量の影響 Effects of Mn content on bending formability of extruded AZ31 magnesium alloy pipes
Formability of extruded round AZ31 magnesium alloy pipes with different manganese concentrations was evaluated by performing bending tests and measuring strain along the length of the pipes during the bending process. It was found that an increase in the amount of manganese content from 0.3% to 0.7% did not exert any significant effect on the values of yield stress, elongation, or compression to fracture, while the values of hardness tended to increase and UTS decreased. The compression ductility was significantly lower than tensile ductility for all manganese concentrations. Accordingly, the formability of pipes decreased, causing cracks in areas where compression strain occurred during bending. It was also found that a larger strain occurred in the latter half of the region along the length of pipe between the clamp-end and pipe positioning block. For alloy pipes with higher manganese concentrations (0.5 and 0.7 Mn mass%), there was a clear strain peak occurring in the strain profile in the region, while for the 0.3 Mn mass% alloy pipe it exhibited a more uniform strain profile along the length of the pipe in this region, indicating that a more uniform deformation took place which was confirmed by microstructure analysis of the specimens.
軽金属 56(12), 705-710, 2006-12-30
The Japan Institute of Light Metals