均匀化退火对7N01铝合金铸锭组织和性能的影响

Effect of homogenization annealing on microstructure and properties of 7N01 aluminum alloy ingots

采用拉伸试验、金相显微镜组织观察和示差扫描量热法等,探讨了均匀化退火工艺对7N01铝合金铸锭组织和性能的影响。结果表明,随着均匀化温度(450℃~490℃)的升高和保温时间(8 h^24 h)的延长,铸锭中残存的化合物减少,枝晶网变得稀薄、不连续,同时基体上析出的弥散质点增加。铸锭组织在489℃出现过烧现象。铸锭的抗拉强度和伸长率随着均匀化温度的升高呈现先增加后降低的现象。7N01铝合金铸锭的最佳均匀化退火工艺为460℃16 h。

The effect of the homogenization annealing process on microstructure and properties of7N01 aluminum alloy ingots was studied by the tensile test, observation of microstructures with metallurgical microscope and differential scanning calorimetry. The result shows that with the rise of homogenization temperature （450℃ -490℃ ） and prolonging of holding time （8 h -24 h） , the residual compounds in the ingots become fewer, and dentritie crystal nets become thin and discontinuous, and in the mean time the dispersoid particles precipitated in the matrix increase. The microstructure of the ingot overburns at 489℃. The tensile strength and elongation of the ingot first increase then decrease, with the rise of homogenization temperature. The best homogenization annealing process for the 7N01 aluminum alloy ingots is 460℃ 16 h.