Formation Mechanism of Ultrafine-Grained Structure by ECAP

1.这是可能的，用于纯A1，用于A1- 1%Mg，用于A1- 3%Mg，用于A1- 1%Mg，用于A1- 3%Mg。镁的添加剂对A1的谷物精炼有影响。重新提炼是因为在隔离流动性中的减少，并导致固体解决方案中恢复的相关较低比率。ECA在压力下揭示的温度变化的直接测量为纯A1 ~ 30°和A1- 3%Mg合金的温度变化为~ 70°。在温度变化和应用负载之间有一个线性关系。However，这种温度增加了ECA冲压期间的精细颗粒结构没有影响。微观结构在0.18毫米/分钟至18毫米/分钟范围内没有改变压力速度的影响。将0.2%Sc添加到A1- 3%Mg合金保留在ECA压力下的小颗粒大小到450弧度的温度。您的位置：知道173> ECA在提高温度时显示，亚颗粒结构在200℃以上的纯A1和A1- 3%Mg温度下开发。However，具有高角度的谷物边界的精细谷物结构即使在300℃的温度下也能找到。“一般稳定粒子的存在对于良好的谷物结构的保留至关重要。”

1. It was possible to obtain grain sizes of 〜μm for pure A1, 〜0.5μm for A1-1%Mg and 〜0.2 μm for A1-3%Mg using equal-channel angular pressing. Addition of Mg was effective to grain refinement of A1. The refinement was achieved because of the reduction in dislocation mobility and to the consequent lower rates of recovery in the solid solution alloys.2. The direct measurements of sample temperature during ECA pressing revealed that the temperature increase is 〜30° for pure A1 and 〜70° for an A1-3%Mg alloy. There was a linear correlation between the temperature increase and the applied load. However, such temperature increases did not affect the fine grain structure during ECA pressing.3. The microstructure did not change irrespective of the pressing speeds within the range of 0.18 mm/min to 18 mm/mini.4. The addition of 0.2%Sc to an A1-3%Mg alloy retained the ECA-pressed small grain size up to a temperature of 450℃. This alloy exhibited the superplastich elongation more than 1000% at a relatively lower temperature of 300℃ with a high strain rate of 3.3x10ィイD1-2ィエD1s-ィイD11ィエD1.5. ECA pressing at elevated temperatures showed that subgrain structures are developed at and above the temperature of 200℃ for pure A1 and A1-3%Mg. However, fine grain structures with high angle grain boundaries were obtained even at a temperature of 300℃. The presence of thermally stable particles was important for the retention of the fine grain structures.