长条状铝合金构件冷热循环尺寸稳定性研究

Effectsof Thermal-cooling Cycle on Dimensional Stability of Strip-shaped Aluminum Alloy Parts

以7A09铝合金长条状构件为对象,采用X射线衍射法,分析了该构件热处理后的残余应力分布。通过冷热循环的方法,采用低温深冷处理系统分别进行了正交工艺试验及典型构件工艺试验,通过圆环法正交试验,分析了不同工艺参数对开口圆环尺寸变化的影响,结果表明,最佳工艺为-140℃×0.8h+120℃×2h,并循环2次。通过典型构件的工艺试验,分析了该工艺对构件残余应力分布的影响。通过机械加工后,采用冷热循环(-140℃×1.2h+120℃×3h,循环2次),可以有效的稳定铝合金加工尺寸。构件最大尺寸变化差值仅0.06mm,已较稳定化处理前的尺寸变化有大幅的减小,平均尺寸变化仅-0.047mm。

Residual stress distribution in the strip-shaped 7A09 aluminum alloy heat treated was examined by the XRD(X-ray diffraction).Effects of thermal-cooling cycle method on residual stress and dimensional changes as well as dimensional stability of the worked parts were tested by orthogonal testing and typical parts working process,respectively,to optimize processing parameters.The results indicate that the working size stability of the strip-shaped 7A09 aluminum alloy parts can be effectively controlled by thermal-cooling cycle treatment.