Artificial Aging Behavior of 6063 Alloy Studied Using Vickers Hardness and Positron Annihilation Lifetime Techniques

2010 ◽  
Vol 303-304 ◽  
pp. 31-38
Author(s):  
M.A. Abdel-Rahman ◽  
Alaa El-Deen ◽  
Alaa El-Deen A. El-Nahhas ◽  
Yahia A. Lotfy ◽  
Emad A. Badawi
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Positron Annihilation ◽  
Vickers Hardness ◽  
Artificial Aging ◽  
Age Hardening ◽  
Solution Temperature ◽  
Precipitate Size ◽  
Positron Annihilation Lifetime ◽  
Precipitation Heat

Many aluminum-based alloys are strengthened by a heat treatment process known as age hardening. The aim of this work was to produce a high-strength 6xxx series aluminum alloy by adjusting the processing conditions, namely solutionizing and artificial aging. It consists of heating the alloy to a temperature at which the soluble constituents will form an homogeneous mass by solid diffusion, holding the mass at that temperature until diffusion takes place, then quenching the alloy rapidly to retain the homogeneous condition. In the quenched condition, heat-treated alloys are supersaturated solid solutions that are comparatively soft and workable, and unstable; depending upon the composition. After solution treatment and quenching, hardening is achieved either at room temperature (natural aging) or by precipitation heat treatment at a suitable temperature (artificial aging). Precipitation heat treatments are generally low-temperature long-term processes. Temperatures range from 115 to 190°C and times vary from 5 to 48 h. Choice of time-temperature cycles for precipitation heat treatment should receive careful consideration. The objective is to select the cycle that produces the optimum precipitate size and distribution pattern. The mechanical characterization of heat-treatable 6xxx (Al-Mg-Si-Cu based) 6063 wrought aluminum alloys was studied. Their effects were investigated in terms of the microstructure, using positron annihilation lifetime techniques and mechanical properties monitoring via Vickers hardness measurements. The hardness is the resistance of a material to plastic deformation, which gives it the ability to resist deformation when a load is applied. The greater the hardness of the material, the greater the resistance it has to deformation. The hardness of 6063 alloy has its maximum value (58) when aged for 8 hours at 175oC after quenching from 520oC; which is the solution temperature of this alloy. The hardness conformed to the literature. We also test the aging ability of the 1xxx aluminum alloy: 1050.

Behaviour of Artificial Aging in 6066 Alloy Using Microhardness and Nuclear Techniques

2010 ◽  
Vol 305-306 ◽  
pp. 15-22
Author(s):  
Emad A. Badawi ◽  
M.A. Abdel-Rahman ◽  
Alaa El-Deen A. El-Nahhas ◽  
M. Abdel-Rahman
Keyword(s):  
Heat Treatment ◽  
Vickers Hardness ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Natural Aging ◽  
Careful Consideration ◽  
Age Hardening ◽  
Solution Temperature ◽  
Precipitate Size ◽  
Precipitation Heat

Many Aluminum-based alloys are strengthened by using a heat-treatment process known as age-hardening. The aim of this work was to produce a high-strength 6xxx-series Aluminum alloy by adjusting the processing conditions, namely solutionizing and artificial aging. It consists of heating the alloy to a temperature at which the soluble constituents will form an homogeneous mass via solid diffusion, holding the mass at that temperature until diffusion takes place, then quenching the alloy rapidly to retain the homogeneous condition. In the quenched condition, heat-treated alloys are supersaturated solid solutions that are comparatively soft and workable, and unstable, depending upon the composition. After solution treatment and quenching, hardening is achieved either at room temperature (natural aging) or via a precipitation heat treatment at a suitable temperature (artificial aging). Precipitation heat treatments are generally low-temperature, long-term processes. Temperatures range from 115 to 190C; times vary from 5 to 48 h. The choice of time-temperature cycles for precipitation heat treatment should receive careful consideration. The objective is to select the cycle that produces an optimum precipitate size and distribution pattern. The mechanical characterization of heat-treatable 6xxx (Al-Mg-Si-Cu based) 6066 wrought aluminum alloys was studied. Their effects were investigated in terms of microstructure using positron annihilation lifetime techniques and monitoring the mechanical properties by mean of Vickers hardness measurements. The hardness is the resistance of a material to plastic deformation, and gives it the ability to resist deformation when a load is applied. The greater the hardness of the material, the greater resistance it has to deformation. The Vickers hardness of 6066 alloy has its maximum value (98) when aged for (10) hours at (175C) after quenching at 530C; so this temperature is the solution temperature of this alloy .The hardness conformed to reference values.

Correlation Coefficient between Vickers Hardness and Nuclear Technique

2013 ◽  
Vol 344 ◽  
pp. 129-136
Author(s):  
Emad A. Badawi ◽  
M.A. Abdel-Rahman ◽  
Alaa El-Deen A. El-Nahhas
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloys ◽  
Severe Plastic Deformation ◽  
Positron Annihilation ◽  
Correlation Coefficient ◽  
Vickers Hardness ◽  
Positron Annihilation Spectroscopy ◽  
Age Hardening ◽  
Nuclear Technique ◽  
Positron Annihilation Lifetime

The aim of this work is to establish a correlation coefficient between the positron annihilation lifetime technique (PALS) and the Vickers hardness for the heat treatable aluminum alloys (6066, 6063).The potential of positron annihilation spectroscopy in the study of light alloys is illustrated with special regards to age hardening, severe plastic deformation, annealing and quenching in aluminum alloys. Vickers hardness is the standard method for measuring the hardness of metals, particularly those with extremely hard surfaces. Accordingly, a correlation coefficient of 90 % between τ and Hv is obtained. This correlation can help us to explain many behaviors of these alloys under deferent conditions.

Testing Natural Aging Effect on Properties of 6066 & 6063 Alloys Using Vickers Hardness and Positron Annihilation Lifetime Techniques

2010 ◽  
Vol 303-304 ◽  
pp. 107-112
Author(s):  
M.A. Abdel-Rahman ◽  
Alaa Aldeen Ahmed ◽  
Emad A. Badawi
Keyword(s):  
Positron Annihilation ◽  
Vickers Hardness ◽  
Natural Aging ◽  
High Strength ◽  
Aging Effect ◽  
Hardness Measurement ◽  
Solution Temperature ◽  
Positron Annihilation Lifetime ◽  
Solid Diffusion ◽  
Maximum Value

The aim of this work was to produce a high strength 6xxx series Aluminum alloy by adjusting the processing conditions, namely solutionizing and natural aging. It consists of heating the alloy to a temperature at which the soluble constituents will form a homogeneous mass by solid diffusion, holding the mass at that temperature until diffusion takes place, then quenching the alloy rapidly to retain the homogeneous condition. In the quenched condition, heat-treated alloys are supersaturated solid solutions that are comparatively soft and workable, and unstable, depending on composition. At room temperature, the alloying constituents of some alloys tend to precipitate from the solution spontaneously, causing the metal to harden in about four days. This is called natural aging. The mechanical characterization of heat treatable 6xxx (Al-Mg-Si-Cu based) 6066, 6063 wrought aluminum alloys was studied. Their effects were investigated in terms of microstructure using positron annihilation lifetime technique and mechanical properties by hardness measurements. The hardness is the Resistance of material to plastic deformation, which gives it the ability to resist deformed when a load is applied. The greater the hardness of the material, the greater resistance it has to deformation. Hardness measurement can be defined as macro-, micro- or nano- scale according to the forces applied and displacements obtained. Micro hardness is the hardness of a material as determined by forcing an indenter such as a Vickers indenter into the surface of the material under 15 to 1000 gf load; usually, the indentations are so small that they must be measured with a microscope. During this work we are monitoring the effect of natural aging on the properties of positron lifetime and Vickers hardness parameters. The Vickers hardness of 6066 alloy has a maximum value(80) after (10)days of quenching at 530 which is the solution temperature of this alloy .the hardness of 6063 alloy has a maximum value (40) after (14)days of quenching at 520 which is the solution temperature of this alloy. The hardness which is conformed to the references.

Effect of Non-Conventional Aging Treatments on the Tensile Properties of Non-Hipped Castings of Aluminum Alloy 354

2014 ◽  
Vol 875-877 ◽  
pp. 1397-1405 ◽  
Author(s):  
G. Dinesh Babu ◽  
M. Nageswara Rao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Tensile Properties ◽  
Artificial Aging ◽  
Natural Aging ◽  
Single Step ◽  
Cast Aluminum Alloy ◽  
Cast Aluminum ◽  
Automobile Components

Cast aluminum alloy 354 is used extensively for production of critical automobile components, owing to its excellent castability and attractive combination of mechanical properties after heat-treatment. With the advent of higher performance engines, there has been a steady demand to further improve the mechanical behavior of the castings made of the alloy, among others, through improvements in processing. The present study explores the possibility of improving tensile properties of the alloy by adopting certain non-conventional aging treatments. The non-conventional treatments include aging cycles similar to T6I4 and T6I6 referred to in the published literature, artificial aging in two steps instead of in single step and artificial aging preceded by various natural aging times. The results show that none of these non-conventional treatments leads to improvement of all tensile properties compared to the standard T61 treatment. Significant hardening takes place in the alloy due to natural aging. Changing the time of natural aging preceding artificial aging was found to have little effect on tensile properties.

Precipitate and Age Hardening Response of As-Cast Mg-8Yb-0.5Zr Magnesium Alloy

2011 ◽  
Vol 399-401 ◽  
pp. 17-20
Author(s):  
Wen Bin Yu ◽  
Zhi Qian Chen ◽  
Mang Zhang ◽  
Zhou Yu
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Grain Boundaries ◽  
Microstructure Evolution ◽  
Solution Heat Treatment ◽  
Artificial Aging ◽  
Precipitation Hardening ◽  
Intermetallic Phase ◽  
Age Hardening ◽  
Maximum Hardness

The precipitation hardening response of as-cast Mg-8Yb-0.5Zr magnesium alloy was investigated in the present work. The microstructure evolution of the alloy illustrated that Mg2Yb intermetallic phase was dissolved by solution heat treatment at 520°C for 12 hours. An apparent precipitation hardening response in Mg-8Yb-0.5Zr was discovered after artificial aging at 150°C, with maximum hardness increment of about 80 percent at the peak condition. It was found that the precipitates of the alloy were in the shape of two conjoined cosh and globe about 50 nm, and precipitated preferentially on grain boundaries and dislocations.

Fatigue Behavior Improvement of A356 Aluminum Alloy of Motorcycle Cast Wheel Produced by High Speed Centrifugal Casting Based on T6 Heat Treatment and Artificial Aging

2020 ◽  
Vol 991 ◽  
pp. 86-93
Author(s):  
Priyo Tri Iswanto ◽  
Akhyar Hasan ◽  
Aditya Janata ◽  
Luthfi Muhammad Mauludin ◽  
Hizba Muhammad Sadida
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
High Speed ◽  
Artificial Aging ◽  
Fatigue Behavior ◽  
Centrifugal Casting ◽  
Aging Treatment ◽  
A356 Aluminum Alloy ◽  
T6 Heat Treatment ◽  
A356 Aluminum

Fatigue behavior of A356 aluminum alloy for motorcycle rim was experimentally investigated based on T6 heat treatment and artificial aging. The high speed of 1,100 rpm from centrifugal casting was used in this study. The pouring temperature at 750 °C was employed and the preheated temperature at 250 °C was applied on the mold. The solution heat treatment of the sample was conducted for 4 hours at 540 o C before it immersed into the water for rapid cooling at room temperature. This step followed by natural aging treatment at 30 °C and artificial aging treatment at 150 °C, 175 °C, and 200 °C for 2 hours, respectively. It is found that increasing centrifugal casting speed into 1,100 rpm combined with heat treatment and artificial aging temperature can significantly increase not only its mechanical properties but also the fatigue life of motorcycle wheel made of A356 aluminum alloy. This experiment proved that the lowest fatigue crack growth rate obtained with this method was at temperature of 175°C.

scholarly journals Effect of Artificial Aging, Delayed Aging, and Pre-Aging on Microstructure and Properties of 6082 Aluminum Alloy

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 173 ◽  
Author(s):  
Xin He ◽  
Qinglin Pan ◽  
Hang Li ◽  
Zhiqi Huang ◽  
Shuhui Liu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Solution Heat Treatment ◽  
Room Temperature ◽  
Artificial Aging ◽  
Experimental Results ◽  
Negative Effects ◽  
Short Term ◽  
6082 Aluminum Alloy

Three different aging treatments including single-aging, delayed-aging, and pre-aging were carried out on 6082 extruded profiles after solution heat treatment, then their hardness, tensile strength, and microstructure were tested. The experimental results reveal that the properties and microstructure changes during single-aging. Based on this, the negative effects of room temperature delay and the results of short-term pre-aging treatments used in the experiment to improve this phenomenon have been concluded.

scholarly journals Effect of Heat Treatment on the Microstructure and Mechanical Properties of a Composite Made of Al-Si-Cu-Mg Aluminum Alloy Reinforced with SiC Particles

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1205
Author(s):  
Li ◽  
Yan ◽  
Wang ◽  
Li ◽  
Liu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Optimal Solution ◽  
Tensile Fracture ◽  
Large Area ◽  
Tensile Fracture Surface ◽  
Sic Particles ◽  
Eutectic Si

In this paper, the effect of heat treatment (solution treatment and artificial aging) on the microstructure and properties of as-cast Al5Si1Cu0.5Mg aluminum alloy and its composite reinforced with 1.5 wt.% SiC particles was studied. The results showed that at 520 °C the optimal solution time for the aluminum alloy and its composite is 9 h and 6 h, respectively. After solution treatment, the microstructure of these two materials consists of a uniform distribution of nearly spherical eutectic Si and skeletal γ phase, furthermore, the composite eutectic Si phase is smaller and γ phase is more dispersed. After artificial aging at 175 °C for 6 h, the microstructure of the composite is more dispersed and finer than that of the aluminum alloy on the whole and Al2Cu is precipitated. After heat treatment, the microhardness, ultimate tensile strength, and elongation of the aluminum alloy and its composite are higher than those of the as-casts. At the same time, the morphology of tensile fracture surface changes very much from a large area of cleavage plane to a large number of dimples and the tearing ridges become thicker for both the aluminum alloy and its composite.

Age Hardening Behavior in Al-8Zn-2Mg-2Cu Wrought Aluminum Alloy

2012 ◽  
Vol 710 ◽  
pp. 527-532
Author(s):  
V. Anil Kumar ◽  
Raghavendra R. Bhat ◽  
Romesh C. Sharma
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aging Time ◽  
Large Scale ◽  
Aluminum Matrix ◽  
High Strength ◽  
Age Hardening ◽  
Stable Phase ◽  
Conductivity Measurements ◽  
Peak Aging

Aluminum alloys based on Al-Zn-Mg-Cu system classified under high strength light alloys, find a large scale application in aerospace sector. In the present study, heat treatment of an Aluminum alloy with Al-8Zn-2Mg-2Cu wt.% (AA7449) was carried out. Heat treatment parameters were optimized based on hardness and conductivity measurements. The mechanisms of strengthening in primary and secondary aged states are explained using hardness and conductivity measurements. Conductivity generally showed an increasing trend with increase in aging time, which could be attributed to decrease in the lattice distortion of the Aluminum matrix with increase in aging time. The dissolution of GP zones and formation of other metastable phases like η’ and stable phase like η were found to reduce the supersaturation in the matrix as the precipitation growth and coarsening processes are completed during overaging. Transmission electron microscopy (TEM) study was carried out to confirm the peak-aging regime. Selected Area Diffraction (SAD) patterns were recorded where GP zones and η’ precipitates were observed in the bright field images to establish their nature. The mechanical properties were correlated with the TEM observations and was suggested that a critical distribution of GP zones and η’ precipitates is essential to achieve peak strength in Al-Zn-Mg alloys.

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