金属热处理 ›› 2020, Vol. 45 ›› Issue (2): 143-148.DOI: 10.13251/j.issn.0254-6051.2020.02.028

• 工艺研究 • 上一篇    下一篇

非等温时效对7003铝合金组织和性能的影响

余罡1, 向剑波2, 赵忠新2, 罗丰华2   

  1. 1. 武汉船用电力推进装置研究所, 湖北 武汉 430000;
    2. 中南大学 粉末冶金国家重点实验室, 湖南 长沙 410083
  • 收稿日期:2019-08-19 出版日期:2020-02-25 发布日期:2020-04-03
  • 通讯作者: 向剑波,硕士研究生,主要从事金属材料热处理工艺,E-mail:2685101622@qq.com
  • 作者简介:余 罡(1976—),男,高级工程师,主要从事燃料电池堆研发,E-mail:13995547579@139.com。

Effect of non-isothermal aging on microstructure and properties of 7003 aluminum alloy

Yu Gang1, Xiang Jianbo2, Zhao Zhongxin2, Luo Fenghua2   

  1. 1. Wuhan Marine Electric Propulsion Research Institute, Wuhan Hubei 430000, China;
    2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha Hunan 410083, China
  • Received:2019-08-19 Online:2020-02-25 Published:2020-04-03

摘要:

结合TEM与力学性能测试对7003铝合金在非等温时效过程中的析出行为和强化规律进行了研究,合金的抗腐蚀性能通过电导率、晶间腐蚀和电化学腐蚀的结果来评估。结果表明:以20 ℃/h升温至180 ℃时,合金的硬度和强度达到了113 HV0.5和367.8 MPa的峰值,与T6态标准相当。在降温阶段180~160 ℃范围内合金能够获得比T74更高的强度和相近的电导率。随着非等温时效的进行,合金的抗腐蚀性能不断提升。GP区和η′相在升温阶段为主要的析出相,到了降温阶段,晶内GP区逐渐消失,η′相不断粗化并有新的细小析出相形成。从升温开始到降温终止,晶界析出相的数量和尺寸越来越大,沿晶界呈断续链状分布,晶界无析出带的宽度也呈稳定增加的趋势。

关键词: 7003铝合金, 非等温时效, 力学性能, 抗腐蚀性能, 显微组织

Abstract:

The precipitation and strengthening rules of 7003 aluminum alloy during non-isothermal aging (NIA) process were researched by combining TEM analysis and mechanical properties test. The corrosion resistance of the alloy was evaluated based on the test results of electrical conductivity, intergranular corrosion and electrochemical corrosion. The test results show that when heated to 180 ℃ at 20 ℃/h, the hardness and strength of the alloy reach their peak values of 113 HV0.5 and 367.8 MPa respectively, which is equivalent to the T6 standard. In the cooling stage in the temperature range of 180-160 ℃, the alloy can obtain higher strength and similar electrical conductivity comparing to the T74 condition. The corrosion resistance is continuously improved during the non-isothermal aging process. GP zones and η′ phases are the primary precipitates at the heating stage, while the GP zones gradually disappear and the η′ phase coarsens, and new fine precipitates are formed in the matrix grains. From the beginning of the heating to the end of the cooling, the number and size of the precipitated phases at the grain boundaries are getting larger and larger, and they are distributed intermittently along the grain boundaries. The width of precipitate free zones also increases steadily.

Key words: 7003 aluminum alloy, non-isothermal aging, mechanical properties, corrosion resistance, microstructure

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