Effect of Retrogression Time on the Mechanical Properties and Stress Corrosion Cracking Behavior of 7A60 Aluminum Alloy

2012 ◽  
Vol 562-564 ◽  
pp. 227-233 ◽  
Author(s):  
Xue Hui Wang ◽  
Ji Hui Wang ◽  
Jie Song ◽  
Cong Wei Fu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Stress Corrosion ◽  
Micro Structure ◽  
Cracking Behavior ◽  
Transmission Electron ◽  
Stress Corrosion Resistance ◽  
Corrosion Behaviors

7A60 aluminum alloy was treated under different retrogression time, and the micro-structure, mechanical properties and stress corrosion behaviors were observed and determined by optical microscopy, transmission electron microscopy and slow strain rate tester. The results shown that with the increasing of retrogression time the precipitates within the grains were gradually grown up, and the precipitates along the grain boundaries were changed from small and closely spaced into coarse and widely spaced ones. The elongation and toughness ratio of 7A60 alloy increased obviously with the retrogression time, whereas the tensile strength and hardness of 7A60 alloy decreased. The optimum retrogression time is about 60min, under which 7A60 alloy has a best combination of tensile strength, ductility and stress corrosion resistance.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Mechanical Properties and Microstructure Evolution of Typical Over-Aging State Al-Zn-Mg-Cu Alloy during Thermal Exposure

2021 ◽  
Vol 1026 ◽  
pp. 84-92
Author(s):  
Tao Qian Cheng ◽  
Zhi Hui Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Electrical Conductivity ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Thermal Exposure ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Thermal Stability Of

Al-Zn-Mg-Cu alloy have been widely used in aerospace industry. However, there is still a lack of research on thermal stability of Al-Zn-Mg-Cu alloy products. In the present work, an Al-Zn-Mg-Cu alloy with T79 and T74 states was placed in the corresponding environment for thermal exposure experiments. Performance was measured by tensile strength, hardness and electrical conductivity. In this paper, precipitation observation was analyzed by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HREM). The precipitations of T79 state alloy were GPⅡ zone, η' phase and η phase while the ultimate tensile strength, hardness and electrical conductivity were 571MPa, 188.2HV and 22.2MS×m-1, respectively. The mechanical property of T79 state alloy decreased to 530MPa and 168.5HV after thermal exposure. The diameter of precipitate increased and the precipitations become η' and η phase at the same time. During the entire thermal exposure, T74 state alloy had the same mechanical property trend as T79 state alloy. The precipitate diameter also increased while the types of precipitate did not change under thermal exposure. The size of precipitates affected the choice of dislocation passing through the particles to affect the mechanical properties.

scholarly journals Effect of Cu on the Fracture and Exfoliation Corrosion Behavior of Al-Zn-Mg-xCu Alloy

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1048 ◽  
Author(s):  
Huibin Jiao ◽  
Kanghua Chen ◽  
Songyi Chen ◽  
Zhen Yang ◽  
Peng Xie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Exfoliation Corrosion ◽  
Cu Content ◽  
Short Transverse ◽  
Transmission Electron ◽  
Corrosion Behaviors ◽  
Mechanical Tensile ◽  
Scanning Electron ◽  
Better Than

In the present work, the influence of Cu content on microstructure, mechanical properties and exfoliation corrosion behaviors of Al-Zn-Mg-xCu alloy extrusions has been investigated in longitudinal-transverse (L-T) and short-longitudinal (S-L) directions by means of mechanical tensile and exfoliation corrosion testing combined with optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that a higher Cu content significantly decreased the fracture toughness and ductility of the alloy in S-L direction compared with L-T direction. Concomitant with the increase in Cu content, a transition in fracture mode was observed from transgranular dimpled rupture to intergranular rupture in S-L direction. Moreover, the exfoliation corrosion (EXCO) resistance of the alloy decreased as the Cu content increased and the exfoliation corrosion resistance of the alloy in short-transverse (S-T) direction was better than that of L-T direction. These results were mainly associated with the large number of coarse intermetallics caused by high Cu content in the L-T direction of alloy.

scholarly journals Research on the Microstructures and Mechanical Properties of Bainite/Martensite Rail Treated by the Controlled-Cooling Process

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3061 ◽  
Author(s):  
Jiajia Qiu ◽  
Min Zhang ◽  
Zhunli Tan ◽  
Guhui Gao ◽  
Bingzhe Bai
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Toughness ◽  
Electron Backscatter Diffraction ◽  
Microstructural Characterization ◽  
Cooling Process ◽  
Controlled Cooling ◽  
Transmission Electron ◽  
Backscatter Diffraction

A bainite/martensite multiphase rail is treated by the controlled-cooling process with different finish-cooling temperatures. The simulated temperature–time curves of the position of 5 mm and 15 mm below the rail tread (P5 and P15) express different trends. P5 has greater impact toughness and lower tensile strength than P15. Microstructural characterization was carried out by conducting scanning electron microscopy, X-ray diffraction, electron backscatter diffraction, and transmission electron microscopy. The greater tensile strength is due to the dispersed ε-carbides hindering the movement of dislocations. The greater impact toughness is attributed to the filmy retained austenite and the smaller effective grain with high-angle boundary. Finite element modeling (FEM) and microstructural characterization reasonably explain the changes of mechanical properties. The present work provides experimental and theoretical guidance for the development of rail with excellent mechanical properties.

Effect of Aging Treatments on Microstructure and Exfoliation Corrosion Behavior of Spray Forming 7075 Alloy

2013 ◽  
Vol 774-776 ◽  
pp. 872-875 ◽  
Author(s):  
Rui Ming Su ◽  
Ying Dong Qu ◽  
Rong De Li ◽  
Qi Ming Xie ◽  
Yu Sheng Wu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Grain Boundaries ◽  
Volume Fraction ◽  
Spray Forming ◽  
Exfoliation Corrosion ◽  
Transmission Electron ◽  
Peak Aging ◽  
7075 Alloy

Mechanical properties, microstructure and exfoliation corrosion (EXCO) behavior of spraying forming 7075 alloy underwent retrogression and re-aging (RRA) were studied by tensile test, transmission electron microscopy and EXCO test, and compared with those of T6 peak aging and T73 overaging treatments. The results show that after T6 treatment, abundance transgranular dispersive η phases make tensile strength of the alloy reach 760MPa, elongation and EXCO rating are only 4.8% and ED respectively by dint of continuous η phases at grain boundaries and narrow precipitate free zones (PFZ). After T73 treatment, interrupted η phases at grain boundaries and wide PFZ can improve elongation and EXCO resistance, but depressed volume fraction of coarsening transgranular η phases reduce tensile strength to 676MPa. After RRA treatment (120°C/24h + 200°C/10min + 120°C/24h), abundance transgranular dispersive η phases separate out again, η phases at grain boundaries interrupt, and PFZ widen slightly. Tensile strength, elongation and EXCO rating of alloy are 758MPa, 8.4% and EA respectively.

Effects of Impulse Current on Mechanical Behavior of Ti and Ta

2013 ◽  
Vol 763 ◽  
pp. 97-101
Author(s):  
Yao Li ◽  
Jun Jie Yang ◽  
Ping Xue ◽  
Wu Xin Yu ◽  
Zhi Jiang Zuo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Slip Systems ◽  
Apparent Effect ◽  
Bcc Metals ◽  
Transmission Electron ◽  
Pure Metals ◽  
Impulse Current

In this paper, pure metals Ti and Ta were used to study the effects of impulse current on their mechanical properties. The results showed that the impulse current caused the tensile strength of the two metals to decline remarkably. The elongation of metal Ta rose and was enhanced with increasing current density. But as for metal Ti, the elongation hardly rose. Theoretical analysis suggested that the impulse current had little apparent effect on HCP metals, for it had less slip systems; however, it had obvious effects on the elongation of BCC metals, for they had more potential slip systems. The transmission electron microscopy (TEM) observations showed that crystal microstructure of the two metals had not changed significantly.

Effect of Heat-Treatment on the Mechanical Properties of TiB2P/2024Al Composite

2007 ◽  
Vol 353-358 ◽  
pp. 1322-1325
Author(s):  
Long Tao Jiang ◽  
Min Zhao ◽  
Rui Jun Fan ◽  
Shao Lei Xu ◽  
De Zhi Zhu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Squeeze Casting ◽  
Hardness Measurement ◽  
Obvious Effect ◽  
Casting Technology ◽  
Transmission Electron ◽  
Peak Aged

55vol% TiB2P/2024Al composite was fabricated by squeeze casting technology, and the effect of heat treatment on mechanical properties of the composites was studied by means of hardness measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and tensile testing etc. Results show that heat treatment has remarkable influence on the hardness and the tensile strength of the composites. For TiB2P/2024Al composites, the composites aged at 130°C for 5h can obtain the highest hardness, and the composites peak-aged at 160°C and aged at 190°C for 24h can obtain the higher tensile strength, which is due to the type of precipitates in the composites. Considering the experimental error, heat treatments has no obvious effect on elastic modulus of the experimental composite.

scholarly journals Changes in Structure of CuCr0.6 Alloy After Repetitive Corrugation Process

2017 ◽  
Vol 62 (4) ◽  
pp. 2441-2448
Author(s):  
T. Jung ◽  
W. Kwaśny ◽  
Z. Rdzawski ◽  
W. Głuchowski ◽  
K. Matus ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Plastic Deformation ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Elastic Limit ◽  
Annealed Sample ◽  
Annealed Alloy ◽  
Transmission Electron

AbstractThis paper presents the study of repetitive corrugation process influence on the strengthening of annealed alloy. Based on the results of mechanical properties of deformed sample, it has been found that the microhardness, ultimate tensile strength, yield strength and apparent elastic limit are significantly increased in relation to annealed sample. Examination on transmission electron microscopy confirmed the effect of intensive plastic deformation on structure fragmentation in the nanometric scale. This work confirmed the possibility of using the repetitive corrugation process to increase mechanical properties of CuCr0.6 alloy.

scholarly journals Effect of Natural Aging on the Stress Corrosion Cracking Behavior of A201-T7 Aluminum Alloy

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5631
Author(s):  
Mien-Chung Chen ◽  
Ming-Che Wen ◽  
Yang-Chun Chiu ◽  
Tse-An Pan ◽  
Yu-Chih Tzeng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Natural Aging ◽  
Corrosion Cracking ◽  
Scanning Calorimetry ◽  
Cracking Behavior ◽  
Free Zone ◽  
Transmission Electron ◽  
Rate Testing

The effect of natural aging on the stress corrosion cracking (SCC) of A201-T7 alloy was investigated by the slow strain rate testing (SSRT), transmission electron microscopy (TEM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), conductivity, and polarization testing. The results indicated that natural aging could significantly improve the resistance of the alloys to SCC. The ductility loss rate of the unaged alloy was 28%, while the rates for the 24 h and 96 h aged alloys were both 5%. The conductivity of the as-quenched alloy was 30.54 (%IACS), and the conductivity of the 24 h and 96 h aged alloys were decreased to 28.85 and 28.65. After T7 tempering, the conductivity of the unaged, 24 h, and 96 h aged alloys were increased to 32.54 (%IACS), 32.52 and 32.45. Besides, the enthalpy change of the 24 h and 96 h aged alloys increased by 36% and 37% compared to the unaged alloy. The clustering of the solute atoms would evidently be enhanced with the increasing time of natural aging. Natural aging after quenching is essential to improve the alloy’s resistance to SCC. It might be due to the prevention of the formation of the precipitation free zone (PFZ) after T7 tempering.

ALUMINUM X7005

Alloy Digest ◽  
1966 ◽  
Vol 15 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Heat Treating ◽  
Aluminum Company ◽  
Stress Corrosion Resistance

Abstract Aluminum X7005 is an age-hardenable aluminum alloy having high mechanical properties, good fracture toughness, good corrosion and stress-corrosion resistance, and good weldability. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-151. Producer or source: Aluminum Company of America.

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