scholarly journals Relationship between hydrogen embrittlement and second-phase particles in a 7075 aluminum alloy

2017 ◽  
Vol 67 (3) ◽  
pp. 67-71
Author(s):  
Toshiaki Manaka ◽  
Goroh Itoh
Keyword(s):  
Aluminum Alloy ◽  
Hydrogen Embrittlement ◽  
Second Phase ◽  
7075 Aluminum Alloy ◽  
Second Phase Particles

Behavior of Hydrogen Invasion in Aluminum Alloys from Different Environments

2011 ◽  
Vol 409 ◽  
pp. 92-95
Author(s):  
Takahito Watakabe ◽  
Goroh Itoh ◽  
Yuji Hatano
Keyword(s):  
Aluminum Alloy ◽  
Tritiated Water ◽  
Second Phase ◽  
7075 Aluminum Alloy ◽  
Metallic Materials ◽  
Silver Particles ◽  
Hydrogen Atoms ◽  
Second Phase Particles ◽  
The Matrix ◽  
Invasion Behavior

Hydrogen embrittlement has been known to occur by invading hydrogen (environmental hydrogen) in some metallic materials under several certain conditions, although the cause has not been clarified yet. To clarify the cause, investigations on the behavior of environmental hydrogen in metallic materials are needed. It has been reported that environmental hydrogen invades 7075 aluminum alloy through the second-phase particles (Al7Cu2Fe). However it has not been clarified yet whether environmental hydrogen invades aluminum through the interface between the matrix and second-phase or through the bulk of second-phase particles. In this study, tritium autoradiography technique, TARG, has been applied to an aluminum alloy containing a single kind of second-phase particles (Al7Cu2Fe), to elucidate the invasion behavior of hydrogen from two different environments: tritiated water and tritium gas. In TARG, hydrogen (tritium) atoms that stay in the vicinity of the surface can be detected as silver particles. Silver particles (hydrogen atoms) were primarily detected on the interface between the matrix and second-phase. Thus most of the invading hydrogen is concluded to be trapped by the interface.

The second phase particles and mechanical properties of 2124 aluminum alloy processed by accumulative back extrusion

2014 ◽  
Vol 58 ◽  
pp. 535-542 ◽  
Author(s):  
P. Shaterani ◽  
A. Zarei-Hanzaki ◽  
S.M. Fatemi-Varzaneh ◽  
S.B. Hassas-Irani
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Second Phase ◽  
Second Phase Particles

Adsorption Behavior of GTMS on AA2024-T3 Aluminum Alloy and the Application on Surface Pretreatment

2020 ◽  
Vol 984 ◽  
pp. 31-42
Author(s):  
Bing Xue ◽  
Xue Mei Zong ◽  
Can Wang ◽  
Hua Yuan Zhang ◽  
Jing Luo
Keyword(s):  
Aluminum Alloy ◽  
Selective Adsorption ◽  
Surface Condition ◽  
Sol Gel ◽  
Adsorption Behavior ◽  
Second Phase ◽  
Surface Pretreatment ◽  
Pretreatment Method ◽  
Second Phase Particles ◽  
Sol Gel Films

Basing on the study of adsorption behavior of glycidoxypropyl-trimethoxy-silane (GTMS), pretreatment method of AA2024-T3 aluminum alloy for sol-gel films was optimized. The morphology, composition and corrosion protective performance of alloy coated with the films were investigated by using FE-SEM, EDS, AFM and EIS. The results showed that the Al matrix exhibited better ability to adsorb GTMS molecules than the second phase particles, especially at lower concentration of GTMS. Further, the 5% GTMS films cover the whole surface, but the selective adsorption behaviors still exist. It was concluded that less second phase particles and smoother surface were benefit to the sol-gel films on aluminum alloy. Depending on this conclusion, the pretreatment method for sol-gel films was optimized. The optimized surface condition conducted with 50 g•L-1 sodium hydroxide and ultrasound at 60 oC for 30 s was obtained. These samples coated with the sol-gel films revealed good anti-corrosion performance. The coverage degree of the films was up to 97.95 %.

Continuous and Discontinuous Recrystallization of 6013 Aluminum Alloy

2013 ◽  
Vol 753 ◽  
pp. 221-224 ◽  
Author(s):  
Krzysztof Sztwiertnia ◽  
Magdalena Bieda ◽  
Anna Korneva
Keyword(s):  
Aluminum Alloy ◽  
Grain Boundaries ◽  
Second Phase ◽  
Sheet Plane ◽  
Temperature Range ◽  
Orientation Mapping ◽  
Second Phase Particles ◽  
The Matrix ◽  
Continuous Recrystallization

In situ orientation mapping using TEM and calorimetric measurements were carried out to investigate the annealing behavior of cold-rolled 6013 aluminum alloy. The recrystallization of the material can be considered to be a number of processes that correspond to two separate stored energy release peaks. In the temperature range of the peak 1, the deformation zones around the large second-phase particles acted as sites for particle-stimulated nucleation. In the matrix, at the same time, some elongation of grains occurred. The elongated matrix grains appeared because of the reduction of the dislocation density and the annihilation of some low-angle grain boundaries between chains of subgrains lying in layers parallel to the sheet plane. The matrix processes in this temperatures range can be considered forms of continuous recrystallization. The matrix high-angle grain boundaries started to migrate at the temperature range of the peak 2. They moved mostly in the direction normal to the sheet plane. Heating of the sample for an appropriate time at those temperatures resulted in the complete discontinuous recrystallization of the material. The recrystallized microstructure was dominated now by elongated grains, which were a few times thicker than those obtained by annealing at the temperatures of the peak 1.

Effect of Heat Treatments on Microstructure and Properties of Hot Compression Aluminum Alloy 7A04

2011 ◽  
Vol 480-481 ◽  
pp. 433-436
Author(s):  
Mu Meng ◽  
Zhi Min Zhang ◽  
Jian Min Yu ◽  
Xin Kai Li
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Second Phase ◽  
Transgranular Fracture ◽  
High Deformation ◽  
Microstructure And Properties ◽  
T6 Heat Treatment ◽  
Second Phase Particles ◽  
The Matrix ◽  
Fracture Appearance

Aluminum alloy 7A04 compressed at high deformation temperature and large deformation is applied in two different heat treatment (T5 and T6), then microstructure and properties of the alloy after heat treatment are investigated. The mechanical properties are studied by means of the tensile testing and the hardness testing. The microstructure characteristics and the fractorgraphy analysis are respectively investigated with optical microscopy and SEM. The experimental results indicate that after T6 heat treatment, the second-phase particles dispersed in the matrix, which can efficiently improving the strength of the alloy, but reduced the toughness. After T5 heat treatment, the coarse and discontinuous second-phase is distributed along the grain boundary, which can lead to the low strength and high toughness because of the lack of the strengthening phase in the grains. The fracture appearance is intercrystalline fracture after T6 heat treatment, and dimple transgranular fracture after T5 heat treatment.

601 Hydrogen embrittlement in a 7075 aluminum alloy subjected to different heat-treatments

2007 ◽  
Vol 2007 (0) ◽  
pp. 131-132
Author(s):  
Goroh ITOH ◽  
Shun IGARASHI ◽  
Yuichi ARAI ◽  
Nobuhide ITOH ◽  
Hitoshi YABUTA
Keyword(s):  
Aluminum Alloy ◽  
Hydrogen Embrittlement ◽  
Heat Treatments ◽  
7075 Aluminum Alloy
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