摘要
To shorten the preparation process of semi-solid billets,semi-solid billets of 2A14 aluminum alloy were prepared by wrought aluminum directly semi-solid isothermal treatment(WADSSIT)process.Three-dimension(3D)combined microstructure evolution,namely transverse direction(TD)surface,rolling direction(RD)surface,and normal direction(ND)surface,was studied.Effects of temperature and holding time on average grain size and average shape factor were investigated.The results showed that the optimum conditions for preparation of 2A14 semi-solid billets by this process were 615℃ and 20 min(average grain size of 124μm and shape factor of 0.81).Electron backscatter diffraction(EBSD)observations indicated that the microstructure was completely recrystallized when it was heated to 600℃.Grain size was increased with the increase of temperature and grew up slowly with the holding time prolonging.Roundness was increased with increase of holding time but was not sensitive to temperature.
为了开发一种制备半固态坯料的短流程工艺,采用变形铝直接半固态等温处理(WADSSIT)工艺制备2A14铝合金半固态坯料。分析横截面、轧面、法面的三维组织演变。研究温度和保温时间对平均晶粒尺寸和平均形状因子的影响。结果表明,该工艺制备2A14半固态坯料的最佳条件为:在615℃下保温20 min,平均晶粒尺寸为124μm,形状因子为0.81。电子背散射衍射(EBSD)观察表明,当加热到600℃时,显微组织完全再结晶。晶粒尺寸随温度的升高而增大,随保温时间的延长而缓慢长大。圆度随保温时间的增加而增加,但对温度不敏感。
基金
financially supported by the National Natural Science Foundation of China (No.51875124)
the National Key Research and Development Project,China (No.2019YFB2006503)。
