Effects of Various Thermal and Environmental Exposure on the Mechanical Properties of Aluminum Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 319-324
Author(s):  
E.W. Lee ◽  
O.S. Es-Said
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Tensile Properties ◽  
Environmental Exposure ◽  
Thermal Exposure ◽  
Age Hardening ◽  
Conductivity Measurements ◽  
Heat Damage ◽  
Quenching Media ◽  
Mechanical Tensile

Aluminum alloys 6061-T6, 7075-T6 and 7249-T76 were subjected to several combinations of solution treatments, quenching media, and age hardening treatments to correlate their mechanical tensile properties to hardness and conductivity measurements. Additionally, the 6061-T6 and 7075- T6 alloys were thermally exposed to several temperatures to simulate heat damage effects. The thermal exposure was correlated to the tensile properties and hardness and conductivity measurements.

CONDULOY

Alloy Digest ◽  
1953 ◽  
Vol 2 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Age Hardening ◽  
Beryllium Copper ◽  
Hardening Heat Treatment

Abstract CONDULOY is a low beryllium-copper alloy containing about 1.5% nickel. It responds to age-hardening heat treatment for improved mechanical properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, machining, and joining. Filing Code: Cu-11. Producer or source: Brush Beryllium Company.

Effects of Post Weld Heat Treatments (PWHT) on Friction Stir Welded AA2219-T87 Joints

2017 ◽  
Author(s):  
Mohammad W. Dewan ◽  
Muhammad A. Wahab ◽  
Khurshida Sharmin
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Yield Strength ◽  
Solution Treatment ◽  
Welding Process ◽  
Alloying Elements ◽  
Age Hardening ◽  
Experimental Program ◽  
Friction Stir ◽  
Aging Period

Friction Stir Welding (FSW) offers significantly better performance on aluminum alloy joints compared to the conventional fusion arc welding techniques; however, plastic deformation, visco-plastic flow of metals, and complex non-uniform heating cycles during FSW processes, result in dissolution of alloying elements, intrinsic microstructural changes, and post-weld residual stress development. As a consequence, about 30% reduction in ultimate strength (UTS) and 60% reduction in yield strength (YS) were observed in defect-free, as-welded AA2219-T87 joints. PWHT is a common practice to refine grain-coarsened microstructures which removes or redistributes post-weld residual stresses; and improves mechanical properties of heat-treatable welded aluminum alloys by precipitation hardening. An extensive experimental program was undertaken on PWHT of FS-welded AA2219-T87 to obtain optimum PWHT conditions and improvement of the tensile properties. Artificial age-hardening (AH) helped in the precipitation of supersaturated alloying elements produced around weld nugget area during the welding process. As a result, an average 20% improvement in YS and 5% improvements in UTS was observed in age-hardened (AH-170°C-18h) specimens as compared to AW specimens. To achieve full benefit of PWHT, solution-treatment followed by age-hardening (STAH) was performed on FS-welded AA2219-T87 specimens. Solution-treatment (ST) helps in the grain refinement and formation of supersaturated precipitates in aluminum alloys. Age-hardening of ST specimens help in the precipitation of alloying elements around grain boundaries and strengthen the specimens. Optimum aging period is important to achieve better mechanical properties. For FS-welded AA2219-T87 peak aging time was 5 hours at 170°C. STAH-170°C -5h treated specimens showed about 78% JE based on UTS, 61% JE based on yield strength, and 36% JE based on tensile toughness values of base metal.

Test Matrix for Heat Exposure of Aluminum Alloys at Various Times and Temperatures

2014 ◽  
Vol 354 ◽  
pp. 175-181
Author(s):  
Abdulhamid Al-Abduljabbar ◽  
O.S. Es-Said
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Tensile Strength ◽  
Aluminum Alloys ◽  
General Relation ◽  
Heat Exposure ◽  
Thermal Exposure ◽  
Static Mechanical ◽  
Hardness Values ◽  
Static Mechanical Properties

The purpose of this study is to characterize the effects of heat damage on the electrical conductivity and static mechanical properties of aluminum alloys. The data resulting from the experiments of thermal exposure of several aluminum alloys are used to model the relations that describe the dependence of the electrical conductivity and hardness on the two main variables of these experiments: the temperature and the time of exposure. The dependence of yield strength and ultimate tensile strength on hardness values is characterized. For each case, different materials (alloys) exhibit similar general trends although there are different coefficients for each material to satisfy the general relation.

scholarly journals Similar and dissimilar welding effect on the mechanical properties of 5383 H34, 5754 H34 and 6005 T6 aluminum alloys

2020 ◽  
Vol 25 (2) ◽  
Author(s):  
Christian Caglioni ◽  
Felipe Mello Rigon ◽  
, Marcelo André Losekann ◽  
Luciana Cristina Soto Herek Rezende ◽  
Mychelle Vianna Pereira Companhoni ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Specific Weight ◽  
Morphological Properties ◽  
Dissimilar Welding ◽  
Mechanical Resistance ◽  
Micro Hardness ◽  
Precipitate Dissolution ◽  
Hardness Tests ◽  
Mechanical Tensile

ABSTRACT Aluminum alloys are not covered by their specific weight. Each class of aluminum alloy presents a set of properties that are favorable to a given function in the same product, just as the alloys may be present in the same vehicle. However, it is necessary to know the changes in the mechanical properties that occur with the union process of these aluminum alloys. The objective of this study was to evaluate the mechanical and morphological properties of alloys 5383 H34, 5754 H34 and 6005 T6 similarly welded and dissimilar by the MIG process. Six combinations of these alloys were characterized by mechanical tensile, folding and Vickers micro-hardness tests, as well as scanning electron microscopy (SEM) and optical microscopy (OM). Among the results obtained, a decrease in tensile strength was observed for all welded alloys. In addition, the microhardness was affected in the melt line, in the weld bead and in the HAZ (heat affected zone). The main causes of the reduction of the mechanical resistance of the welded alloys were the grain growth and the precipitate dissolution. The data obtained in this study contribute in a very positive way to the development and dimensioning of new projects and technologies involving aluminum alloys.

Evolution of Mechanical Properties and Microstructural Characterization of Aluminum AA-6061 Butt-Welded Joints

2011 ◽  
Author(s):  
Ajay A. Kardak ◽  
M. A. Wahab
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloys ◽  
Fracture Surface ◽  
Welded Joints ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
Age Hardening ◽  
Welding Processes ◽  
Weld Heat

Aluminum alloys because of their high strength to weight ratio have various applications as structural material in railways, ship building, aeronautics, construction, and consumer appliances. This increased use of aluminum alloys calls for more efficient and reliable welding processes which has always represented a great challenge for designers and technologists. AA-6061 Aluminum Alloy (Al-Mg-Si) is widely used in the aircraft industry and has gathered wider acceptance in the fabrication of light weight structures. The preferred welding process for this alloy is Tungsten Inert Gas (TIG) process due to their comparatively easier applicability, high yield, and better economy. Major difficulties are associated with this type of welding process, such as, the presence of tenacious oxide layer, high coefficient of thermal expansion, solidification shrinkage, solubility of hydrogen, and other gases in the molten state. Furthermore, problems such as decay of mechanical properties due to phase transformation and softening can occur in the heat-affected-zone (HAZ). Post weld heat treatment can be used to improve the strength of the HAZ for heat-treatable alloys like AA-6061. Hence, the major objectives of this work was to conduct a systematic study and gain an in-depth understanding of the effect of post-weld heat treatment (PWHT) of these joints on tensile properties, micro hardness, microstructure, and fracture surface morphology of butt-welded joints. It was found that of all the PWHT processes, Age-hardening (AH) resulted in superior mechanical properties and hardness. The reason for this enhanced strength has also been studied from metallurgical point of view. Microstructure and fracture surface of the tensile tested specimens were studied using light microscope and scanning electron microscope, respectively. Correlation has been drawn between the tensile test results, microhardness and the metallurgical results. It was found that the uniformly dense precipitation of fine Mg2Si, and the lack of precipitate-free zone could be the reason for the superior results found.

Forming of AA2xxx and AA7xxx Sheet Alloys and their Studies on Microstructural and Mechanical Properties of Cold and Cryo Rolled Aluminum Alloys

2019 ◽  
Vol 969 ◽  
pp. 546-551
Author(s):  
J. Suresh Kumar ◽  
M. Siva ◽  
N. Suneel Kumar ◽  
CH.V.V.S.S.R Krishna Murthy ◽  
V.V. Ravi Kumar
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Cold Rolling ◽  
Tensile Properties ◽  
High Strength ◽  
Thermal Recovery ◽  
Rolled Aluminum ◽  
High Strength Aluminum Alloys

High strength aluminum alloys will enhancing mechanical properties always plays a major role in controlling microstructure of cast and processed alloy. The desire for more efficient aircraft materials has fueled research of aluminum AA-2xxx and AA7xxx alloys. In these alloys were rolled at cold rolling and at cryorolling to 80 % thickness reductions and an attempt was made to evaluate the optical-microstructural variation and the variation in tensile properties of these aluminum alloys. Cryorolled alloy also exhibited better hardness and strength compared to cold alloy due to suppressed thermal recovery. Coldrolled alloy showed more necking percentage compared to cryorolled for rolling reductions of 80% and more formability was observed.

Dilute Alloy Designs of 7xxx Aluminum Alloys for Thick Forging Applications

2005 ◽  
Vol 475-479 ◽  
pp. 369-372 ◽  
Author(s):  
Seong Taek Lim ◽  
Yong Yun Lee ◽  
Il Sang Eun
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Age Hardening ◽  
Homogeneous Precipitation ◽  
The Novel ◽  
Slow Quench ◽  
Equilibrium Phases ◽  
Dilute Alloy ◽  
Microstructural Homogeneity ◽  
Optimum Alloy

An effort has been made to present optimum alloy designs of commercial 7175 and 7050 type alloys to be used in thick forgings with proper microstructures and properties. The effects of changing alloy constitutions, primarily [Zn+Mg+Cu] and Zn:Mg ratio, on the evolutions of the coarse equilibrium phases and age hardening response are investigated. As a result, equilibrium phases (M,T,S) are evolved depending on alloy constitutions and cooling rate following solutionizing. The formation of the T- and S-phases is effectively controlled in the novel alloys (dilute and with high Zn:Mg ratio). In the slow quench, the redesign promotes homogeneous precipitation of η-phases, leading to higher mechanical properties than conventional alloys. The novel alloys provide microstructural homogeneity and extended heating range, ensuring 7xxx thick forging applications.

scholarly journals Effect of Aging Time on Microstructure and Mechanical Properties in a Cu-Bearing Marine Engineering Steel

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3638
Author(s):  
Mingxue Sun ◽  
Yang Xu ◽  
Jin Wang
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Tensile Properties ◽  
Aging Time ◽  
Aging Process ◽  
Age Hardening ◽  
Face Centered Cubic ◽  
Dislocation Interaction ◽  
Engineering Steel ◽  
Marine Engineering

This study elucidated the structure–property relationship in a Cu-bearing marine engineering steel that was water cooled and then aged at 500 °C for 0.5–3 h. The microstructural features, tensile properties and impact properties were comparatively investigated as a function of aging time. When the aging period was increased, the Cu precipitates underwent coarsening, and a stable face-centered cubic (fcc) formation occurred. Additionally, the tensile properties were significantly improved at the expense of low temperature toughness, which can be attributed to the presence of nano-sized Cu precipitates. The increment of yield strength mainly derived from Cu precipitate–dislocation interaction strengthening effects (232 MPa for 1 h and 199 MPa for 3 h.) during aging process. Therefore, optimization of mechanical properties was achieved by controlling the parameters of aging process. The peak age hardening condition (i.e., at 500 °C for 1 h) resulted in the yield strength of 755 MPa, tensile strength of 812 MPa, elongation of 26.3% and impact energy of 78 J at −80 °C.

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