金属热处理 ›› 2020, Vol. 45 ›› Issue (3): 169-173.DOI: 10.13251/j.issn.0254-6051.2020.03.033

• 工艺研究 • 上一篇    下一篇

非等温时效工艺对7050铝合金组织和性能的影响

陈庚1,2, 苗景国1, 方琴1, 孙文文2, 张光明1,3, 王正云2   

  1. 1. 四川工程职业技术学院 四川省航空材料检测与模锻工艺技术工程实验室, 四川 德阳 618000;
    2. 西华大学 材料科学与工程学院, 四川 成都 610039;
    3. 中国第二重型机械集团 德阳万航模锻有限责任公司, 四川 德阳 618000
  • 收稿日期:2019-09-26 出版日期:2020-03-25 发布日期:2020-04-03
  • 通讯作者: 王正云,高级实验师,博士,主要从事高性能结构材料研究,E-mail:wzy-513@163.com
  • 作者简介:陈 庚(1981—),男,副教授,硕士,主要从事材料加工工程、金属材料热处理技术研究,E-mail:16380001@qq.com。
  • 基金资助:

    德阳市科技支撑计划项目(2018SZY067);四川工程职业技术学院院级科研项目(YJ2017GC-07,YJ2018KY-03)

Effect of non-isothermal aging process on microstructure and properties of 7050 aluminum alloy

Chen Geng1,2, Miao Jingguo1, Fang Qin1, Sun Wenwen2, Zhang Guangming1,3, Wang Zhengyun2   

  1. 1. Sichuan Laboratory of Aerial Material Testing and Die Forging Technology, Sichuan Engineering Technical College, Deyang Sichuan 618000, China;
    2. School of Materials Science and Engineering, Xihua University, Chengdu Sichuan 610039, China;
    3. Deyang Wanhang Die Forging Co., Ltd., China National Erzhong Group Co., Ltd., Deyang Sichuan 618000, China
  • Received:2019-09-26 Online:2020-03-25 Published:2020-04-03

摘要:

利用TEM、SEM、维氏硬度计、电子万能试验机和涡流导电仪等手段研究了不同的非等温时效工艺对7050铝合金组织、断口形貌和性能的影响,并与T74态的7050铝合金性能进行了比较。结果表明,经190 ℃时效后合金晶内以η′相为主析出,析出相间距较大;随着时效温度的降低,晶内析出相不断增大,间距不断减小,并伴随有针状相二次析出。晶界析出相同样不断粗化,且呈现出“连续状-项链状-半连续状-间断状”的分布势态,晶界无析出带变化不大;合金的硬度、抗拉强度均呈现出先升后降的趋势,当时效温度为130 ℃时,合金的硬度、抗拉强度达到峰值;合金的电导率呈现出单调上升的趋势,在时效温度为110 ℃时趋于平稳;与T74态相比,经(475±3) ℃×40 min固溶+(210~130 ℃,20 ℃/h)非等温时效处理后,合金获得了更优异的综合性能,且工艺耗时减少24 h。

关键词: 非等温时效, 7050铝合金, 组织, 性能

Abstract:

Effects of different non-isothermal aging processes on the microstructure, fracture morphology and properties of 7050 aluminum alloy were studied by using TEM, SEM, Vickers hardness tester, electronic universal testing machine and eddy current conductivity tester, then the properties of the aged alloy were compared with that in T74 state. The results show that, after aging at 190 ℃, the main intracrystalline precipitation phase is η′ and the phase spacing is relatively large. The intragranular precipitates increase and the spacing decreases with the decrease of the aging temperature, and accompanied by secondary precipitation of needle-like precipitates. The precipitates at the grain boundary become coarser continuously, and tend to change from continuous to necklace-like to semi-continuous then to disconnected distribution, and the width of PFZ (precipitate-free zone) has little change. The hardness and tensile strength of the alloy increase first and then decrease, their peak values can be obtained when aged at 130 ℃. The conductivity of the alloy shows a monotonous upward trend and it tends to be stable when aged at 110 ℃. Compared with that in T74 state, the alloy can obtain a better comprehensive properties after solution treatment at (475+3) ℃ for 40 min and non-isothermal aging from 210 ℃ to 130 ℃ by a cooling rate of 20 ℃/h, with a reduction of the process time of 24 h.

Key words: non-isothermal aging, 7050 aluminum alloy, microstructure, properties

中图分类号: