(中國航空制造技術(shù)研究院，北京 100024)
摘 要: 粗晶環(huán)是鋁合金擠壓型材內(nèi)常見的組織結(jié)構(gòu)，降低了組織與性能的均勻性。本文設(shè)計了一系列階梯式熱處理工藝，利用不同溫度階段的回復(fù)作用消除變形過程累積的畸變能，控制固溶后超高強Al-Zn-Mg-Cu合金擠壓型材內(nèi)粗晶環(huán)的尺寸。結(jié)果表明：經(jīng)(250 ℃, 24 h)、(300 ℃, 24 h)、(350 ℃, 24 h)、(400 ℃, 24 h)熱處理后，粗晶環(huán)平均寬度降至未經(jīng)處理的1/10~1/7，同時沿厚度方向拉伸性能均勻性顯著提高。本研究為優(yōu)化超高強Al-Zn-Mg-Cu合金型材的組織與性能提供了可參考辦法。
關(guān)鍵字: 超高強鋁合金；Al-Zn-Mg-Cu；粗晶環(huán)；熱處理；晶粒組織；力學(xué)性能
（AVIC Manufacturing Technology Institute, Beijing 100024, China）
Abstract:Coarse crystal ring is a common structure in the extruded Al alloy profiles, which reduces the homogeneity of the microstructures and properties. In this work, a series of step heat treatment processes were designed, in which the distortion energy of deformation process was eliminated by using the recovery effect at different temperature stages to control the size of the coarse-grained rings after solution treatment. The results show that the average width of the coarse-grained rings decreases from 1/10 to 1/7 of the untreated one after the heat treatment of (250 ℃, 24 h)+(300 ℃, 24 h)+(350 ℃, 24 h)+(400 ℃, 24 h), and the uniformity of mechanical properties along the thickness direction enhances significantly. This work may provide a reference method for optimizing the microstructure and properties of the ultra-high strength Al-Zn-Mg-Cu alloy profiles.
Key words: ultra-high strength alloy; Al-Zn-Mg-Cu; coarse-grained rings; heat treatment; grain structure; mechanical properties
