Effect of Two-stage Ageing on Mechanical Properties and Sensitivity to Hydrogen Embrittlement of 7050 Aluminum Alloy

doi:10.11902/1005.4537.2018.160

Journal of Chinese Society for Corrosion and protection

2019, Vol. 39

Issue (4): 359-366 DOI: 10.11902/1005.4537.2018.160

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Effect of Two-stage Ageing on Mechanical Properties and Sensitivity to Hydrogen Embrittlement of 7050 Aluminum Alloy

REN Jianping¹,SONG Renguo²(

)

1. Taizhou Vocational College of Science and Technology, Taizhou 318020, China
2. School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China

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Abstract

The effect of two-stage ageing heat treatment on the mechanical performance and sensitivity to hydrogen embrittlement for 7075 Al-alloy was assessed by means of tensile tester, hardness tester and cross section morphology observation, as well as cathodic hydrogen permeability method, hydrogen meter, EDS and SEM. The results show that the double peak phenomenon emerged for the two-stage ageing heat-treated 7050 Al-alloy, and the elongation decreases basically with the ageing process, while the peak positions fluctuate to certain extend. The hydrogen content increases with the extension of hydrogen charging time. From the perspective of the same hydrogen charging time, the hydrogen content is the lowest at the peak of the second ageing, however the alloy presented strong toughness. Scanning electron microscopy (SEM) revealed that the improvement of the second peak strength and hardness is due to the increased amount of η', while the plastic toughness increase is mainly ascribed to that η' phase particles evenly dispersed in the matrix, leading to the uniformity in deformation.

Key words: 7050 aluminum alloy two-stage ageing toughening mechanism fracture toughness hydrogen embrittlement

Received: 03 November 2018

ZTFLH:

TG178

Fund: Supported by National Natural Science Foundation of China(50771093 and 51371039)

Corresponding Authors: Renguo SONG E-mail: songrg@hotmail.com

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Cite this article:

REN Jianping,SONG Renguo. Effect of Two-stage Ageing on Mechanical Properties and Sensitivity to Hydrogen Embrittlement of 7050 Aluminum Alloy. Journal of Chinese Society for Corrosion and protection, 2019, 39(4): 359-366.

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https://www.jcscp.org/EN/10.11902/1005.4537.2018.160 OR https://www.jcscp.org/EN/Y2019/V39/I4/359

Fig.1 Front (a) and sectional (b) views of 7050 aluminum alloy specimen for compact tensile test

Fig.2 Experimental device for hydrogenation of 7050 aluminum alloy sample

Fig.3 Tensile specimen of 7050 aluminum alloy: (a) dimensional drawing, (b) optical macrograph

Fig.4 Variations of hardness, strength, and elongation of 7050 aluminum alloy with ageing time under various aging conditions: (a) 743 K/70 min+383 K/8 h+423 K/long time; (b) 743 K/70 min+383 K/8 h+433 K/long time; (c) 743 K/70 min+393 K/8 h+423 K/long time; (d) 743 K/70 min+393 K/8 h+433 K/long time

Fig.5 Fracture morphologies of 7050 Al alloy after ageing under the conditions of 743 K/70 min+393 K/8 h+423 K/different time: (a) 17 h (first peak); (b) 33 h (vale); (c) 45 h (second peak); (d) 57 h (after second peak)

Table 1 Contents of various alloying elements at the points of A and B in Fig.5c and d (mass fraction / %)

Table 2 Hydrogen content of 7050 aluminum alloy after hydrogen charging

Table 3 Mechanical properties of 7050 aluminum alloy under the condition of tensile at low strain rate

Fig.6 Fracture surfaces of 7050 aluminum alloy after ageing under the conditions of 743 K/70 min+393 K/8 h+423 K/different time and then hydrogen charging for 3 h; (a) 17 h (first peak), (b) 33 h (vale), (c) 45 h (second peak), (d) 57 h (after second peak)

Fig.7 Intragranular and grain boundary structures of 7050 aluminum alloy after ageing under the cond-itions of 743 K/70 min+393 K/8 h+423 K/different time: (a) 17 h (first peak); (b) 33 h (vale); (c) 45 h (second peak); (d) 57 h (after second peak)

Fig.8 High-resolution intragranular images of 7050 aluminum alloy after ageing under the conditions of 743 K/70 min+393 K/8 h+423 K/ different time: (a) 17 h (first peak), (b) 45 h (second peak)

[1]	SongR G, ZengM G, ZhangJ B, et al. Investigation of relation between grain boundary segregation and behavior of stress corrosion and corrosion fatigue in 7075 aluminium alloy [J]. J. Chin. Soc. Corros. Prot., 1996, 16: 1
[1]	(宋仁国, 曾梅光, 张金宝等. 7050铝合金晶界偏析与应力腐蚀、腐蚀疲劳行为的研究 [J]. 中国腐蚀与防护学报, 1996, 16: 1)
[2]	ZhangY, SongR G, TangP H. hydrogen embrittlement susceptibility and Mg-H interaction in 7075 aluminum alloy [J]. J. Chin. Soc. Corros. Prot., 2010, 30: 364
[2]	(张宇, 宋仁国, 唐普洪. 7075铝合金氢脆敏感性与Mg-H相互作用 [J]. 中国腐蚀与防护学报, 2010, 30: 364)
[3]	RenJ P, SongR G, ChenX M, et al. Development and states of heat-treatment process for 7xxx series aluminum alloys [J]. Hot Work. Technol., 2009, 38(6): 120
[3]	(任建平, 宋仁国, 陈小明等. 7xxx系铝合金热处理工艺的研究现状及进展 [J]. 热加工工艺, 2009, 38(6): 120)
[4]	GecuR, AcarS, KisasozA, et al. Influence of T6 heat treatment on A356 and A380 aluminium alloys manufactured by thixoforging combined with low superheat casting [J]. Trans. Nonferrous Met. Soc. China, 2018, 28: 385
[5]	ZhangW W, HuY, ZhangG Q, et al. Formation of nanoscale metallic glassy particle reinforced al-based composite powders by high-energy milling [J]. Metals, 2017, 7: 425
[6]	QiX, JinJ R, DaiC L, et al. A study on the susceptibility to SCC of 7050 aluminum alloy by DCB specimens [J]. Materials, 2016, 9: 884
[7]	YanD J. Analysis about strengthening mechanism from the ageing process of 7475 Al alloy [J]. J. Mater. Eng., 1992, (2): 15
[7]	阎大京. 从7475铝合金的时效看Al-Zn-Mg-Cu系合金的强化 [J]. 材料工程, 1992, (2): 15)
[8]	ChenX M, SongR G. Study on double-peak ageing process for 7xxx series aluminum alloy [J]. Hot Work. Technol., 2009, 38(2): 93
[8]	(陈小明, 宋仁国. 7xxx系铝合金“双峰”时效工艺的普适性研究 [J]. 热加工工艺, 2009, 38(2): 93)
[9]	RenJ P, SongR G, ChenX M, et al. Optimization of heat treatment of 7003 aluminum alloy based on BP neural networks gradient descent algorithms [J]. Aerosp. Mater. Technol., 2009, 39(4): 6
[9]	(任建平, 宋仁国, 陈小明等. 基于BP神经网络梯度下降算法的7003铝合金热处理工艺优化 [J]. 宇航材料工艺, 2009, 39(4): 6)
[10]	NingA L, ZengS M. Effect of aging system on microstructure and mechanical properties of 7B04 aluminum alloy [J]. Chin. J. Nonferrous Met., 2004, 14: 922
[11]	LukasakD A, HartR M. Aluminum alloy development efforts for compression dominated structure of aircraft [J]. Light Met. Age, 1991, 49(9): 11
[12]	LiH, WangZ X, ZhengZ Q. High temperature pre-precipitation treatment of 7050 aluminum alloy [J]. Rare Met. Mater. Eng., 2008, 37: 674
[12]	(李海, 王芝秀, 郑子樵. 7050铝合金高温预析出处理 [J]. 稀有金属材料与工程, 2008, 37: 674)
[13]	PickensJ R. Aluminium powder metallurgy technology for high-strength applications [J]. J. Mater. Sci., 1981, 16: 1437
[14]	LiC M, ChenZ Q, ChengN P, et al. Study of heat treatment scheme of ultrahigh-strength, ultrahigh-ductility aluminum alloy [J]. Light Alloy Fabric. Technol., 2007, 35(12): 36
[14]	(李春梅, 陈志谦, 程南璞等. 超高强超高韧铝合金的热处理工艺研究 [J]. 轻合金加工技术, 2007, 35(12): 36)
[15]	HuH, WangX Y. Effect of heat treatment on the in-plane anisotropy of as-rolled 7050 aluminum alloy [J]. Metals, 2016, 6: 79
[16]	ScamansG M, HolroydN J H, TuckC D S. The role of magnesium segregation in the intergranular stress corrosion cracking of aluminium alloys [J]. Corros. Sci., 1987, 27: 329
[17]	SongR G, DietaelW, ZhangB J, et al. Stress corrosion cracking and hydrogen embrittlement of an Al-Zn-Mg-Cu alloy [J]. Acta Mater., 2004, 52: 4727
[18]	SongR G, ZhangB J, ZengM G, et al. Investigation of hydrogen induced ductile brittle transition in 7175 aluminum alloy [J]. Acta Metall. Sin., 1996, 9: 287
[19]	SongR G, GengP, ZenM G, et al. Aging characteristics, stress corrosion behaviour and role of Mg segregation at grain boundary in 7175 high-strength Al alloy [J]. J. Mater. Sci. Technol., 1998, 14: 259
[20]	TakanoN. Hydrogen diffusion and embrittlement in 7075 aluminum alloy [J]. Mater. Sci. Eng., 2008, A483/484: 336

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