不同形变储能超高强铝合金在快速慢速升温过程中的微结构演变

Microstructure evolution of different initial deformation energy storage ultra high strength aluminum alloy by different heating rate

摘要:

采用电导率、硬度测试、X射线衍射仪显微分析(XRD)、电子背散射衍射检验(EBSD)，研究了不同初始形变储能微合金化超高强铝合金Al-11.54Zn-3.51Mg-2.26Cu-0.24Zr在快速、慢速升温过程中的微结构演变。结果表明：升温过程中合金电导率先增大后减小，硬度先减小后增大。合金位错在退火温度达到300 ℃至450 ℃时降低为0，温度达到470 ℃时，重新产生了位错。合金在升温退火至300 ℃晶粒平均尺寸略有降低，退火至470 ℃的合金晶粒尺寸显著增大。初始形变储能的提高能够降低晶粒平均尺寸、低角度晶界比例，提高位错与晶界强化。

Abstract:

The effects of different initial energy storage on the properties of Al-11.54Zn-3.51Mg-2.26Cu-0.24Zr super high strength aluminum alloy at different heating rates were explored by electrical conductivity,hardness EBSD and XRD analysis. The results show that the conductivity increases and then decreases with the increase of temperature, the hardness decreases and then increases with the increase of temperature.The dislocation density of the alloy is reduced to 0 when the annealing temperature is between 300 ℃ and 450 ℃, and the dislocation is re produced when the annealing temperature reaches 470 ℃. The average size of alloy decreases slightly during heating annealing to 300 ℃ grain, grain size of the alloy annealed to 470 ℃ increased significantly. Improving the initial deformation energy storage, the average grain size and low angle grain boundaries has been significantly reduced, dislocation and grain boundary strengthening has improved.