Solution Heat Treatment of 7075 Aluminum Alloy Affected on Anodic Oxide Layer

2016 ◽  
Vol 867 ◽  
pp. 19-23 ◽  
Author(s):  
Itsaree Iewkitthayakorn ◽  
Somjai Janudom ◽  
Narissara Mahathaninwong

This research focused on the effect of solution heat treated microstructures on anodic oxide formations of casting 7075 Al alloy. The casting specimens were solution heat treated at 450°C for various holding. The results showed that the quality of anodic oxide film on the specimen with 4h solution heat treatment time was higher than that of at other conditions. Because its microstructures obtained the lowest amounts of secondary phase particles leading to improve the quality of oxide film and also reduce defects in oxide film. On the other hand, coarse black particles of Mg2Si formed increasingly in microstructures of specimens after solution treatment at prolong holding time of 8h and 16h resulted in discontinues oxide films forming on them.

2004 ◽  
Vol 467-470 ◽  
pp. 399-406 ◽  
Author(s):  
M.A. Moustafa ◽  
F.H. Samuel ◽  
H.W. Doty

A study was carried out to determine the role of additives such as Mg and Cu on the microstructural characteristics of grain refined, Sr-modified eutectic A413.1 alloy (Al-11.7% Si) during solution heat treatment. For comparison purposes, some of the alloys were also studied in the non-modified condition. The alloys were cast in a steel permanent mold preheated at 425 °C that provided a microstructure with an average dendrite arm spacing (DAS) of ~ 22 µm. Castings were solution heat treated at 500 ± 2 °C for time up 24 h, followed by quenching in warm water (at 60 °C). Microstructural analysis of the as-cast and heat-treated castings was carried out using optical microscopy in conjunction with image analysis. Phase identifications were done using the electron probe microanalysis (EPMA) technique. In the as-cast condition, the addition of 0.42 wt% Mg to the unmodified alloy produced relatively large Si particles compared to the base A413.1 alloy. The Si particle size remained more or less the same with increase in solution treatment time and Mg level. Both Mg2Si and Al2Cu phases were observed to dissolve almost completely after 8 h solution time, while the Al5Cu2Mg8Si6 phase was found to persist even after 24 h.


2020 ◽  
Vol 67 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Anasyida Abu Seman ◽  
Ji Kit Chan ◽  
Muhammad Anas Norazman ◽  
Zuhailawati Hussain ◽  
Dhindaw Brij ◽  
...  

Purpose This paper aims to investigate the corrosion behaviour of heat-treated and cryorolled Al 5052 alloys in different Cl− ion concentrations. Design/methodology/approach NaCl solutions with concentrations of 0, 0.5, 3.5 and 5.5 per cent were selected. Samples were subjected to pre-heat treatment (annealing at 300 °C and solution treatment at 540 °C) and cryorolling up to 30 per cent reduction before undergoing corrosion tests. The corrosion behaviour of the samples was then investigated by potentiodynamic polarization. The microstructure of the corroded samples was evaluated under an optical microscope, and the percentages of pits on their surfaces were calculated. Findings The cryorolled samples had a lower corrosion rate than the samples that were not cryorolled. The cryorolled sample that underwent solution treatment showed the highest corrosion resistance among all the samples tested. Practical implications The commercial impact of the study is the possibility of using the cryorolled Al alloy in various ion chloride environment. Originality/value The obtained results help in understanding the corrosion behaviour of cryorolled samples under different heat treatment conditions.


2019 ◽  
Vol 22 ◽  
pp. 109-117
Author(s):  
Wesley Walker ◽  
Rudolf Marloth ◽  
Ye Thura Hein ◽  
Omar S. Es-Said

This study aimed to characterize the effects of incomplete solution treatment time on the tensile behavior of 2195 Al-Li alloy. Two sets of plates of 2195 Al-Li alloy received solution heat treatment. One set received the prescribed treatment, held in the furnace for 30 minutes after the material had reached 507°C. The other set was in the furnace for only 30 minutes and did not reach 507°C until after about 15 to 20 minutes. Both set of plates were water quenched. Samples from the plates were then stretched 2.5-3% or 6%, rolled 6%, and rolled 24%, at 0°, 45°, and 90° relative to the rolling direction of the as-received material. The samples were aged at 143°C for 36 hours and air-cooled. Tensile specimens were milled out at 0°, 45°, and 90° relative to the original rolling direction. Tensile testing was performed on all samples. The incomplete heat treatment (incomplete solution treatment) resulted in a significant reduction in strength. This was probably due to the formation of fewer T1 precipitates after aging, thereby reducing the amount which could nucleate during cold work. The fully heat treated samples had higher percent yield strength, ultimate strength, and elongation.


2018 ◽  
Vol 157 ◽  
pp. 02053 ◽  
Author(s):  
Eva Tillová ◽  
Mária Chalupová ◽  
Lenka Kuchariková ◽  
Juraj Belan ◽  
Denisa Závodská

The effect of solution treatment on mechanical properties (UTS, elongation, Brinell hardness) and microstructure (Si-morphology and Si-size) of an aluminium alloy (A356) used for casting cylinder heads was studied. The tests were carried out with specimens machined from the bulkheads of V8 engine blocks cast by the low pressure process. The samples were tested in as-cast and T6 heat treating conditions (solution heat treatment at 530°C with different time - 2, 3, 4, 5, 6, 7 hours, quenching in water at 20°C and precipitation hardened for 4 hour at 160°C). The results show that used heat treatment improves mechanical properties of the cylinder head casts. Tensile strength and hardness of specimens increase with solution treatment time. The hardness is a reflection of solution strengthening and silicon particle distribution in matrix. Solution temperature 530°C and 5 hours solution time is appropriate to obtain better morphology and distribution of Si particles in microstructure. Prolonged solution treatment (more than 5 hours) leads to a coarsening of the Si particles, while the numerical Si density decreases. As the particle density decreases, a fewer number of sites are available for crack nucleation, and hence, the fracture properties are improved. The data obtained from this study will be used to improve process control, and to help the selection of heat treatment of the casting for future products.


2011 ◽  
Vol 339 ◽  
pp. 714-717 ◽  
Author(s):  
Siriwan Pannaray ◽  
Sirikul Wisutmethangoon ◽  
Thawatchai Plookphol ◽  
Jessada Wannasin

The aim of this study is to determine the appropriate solution treatment temperature and time of semi solid 2024 Al alloy. Solution heat treatment at 450°C and 480 °C for various times, from 4 hours to 16 hrs, were applied followed by artificial aging at 220 °C for 1 hr. Microstructure of the semi solid cast 2024 aluminum alloy mainly showed globular grain structure which consisted of matrix-α (Al) and grain boundary (GB) - eutectic phases (α+Al2CuMg/Al2Cu). Eutectic GB phases was found to completely dissolved after solution heat treatment at 480°C for 14 hrs while sample solution treated at 450°C for the same time showed the existence of remaining GB phases. Prolonging heat treatment after 14 hrs at both temperatures resulted in the formation of coarse black particles at the grain boundaries which were identified as Mg2Si phases. Therefore the suitable solution treatment of the alloy in this study was at 480°C for 14 hrs.


2013 ◽  
Vol 773-774 ◽  
pp. 785-794
Author(s):  
Amir Mahmoudi ◽  
Mohammad Esmailian ◽  
Seyed Eshagh Aghamiri

In this investigation, AISI321 steel was solution - stabilizing post heat treated in various temperatures and times after SMAW welding. Results show, increasing of temperature in solution and stabilizing heat treatment, raise sensitization; in addition, by increasing of the solution heat treatment time, sensitization enhances. However, increasing the time of stabilizing heat treatment creates less chrome carbides, so the sensitization decreases. These heat treatments reduce the amount of delta ferrite and change its morphology from narrow and acicular shape to discontinues and separate globular particles. Moreover, more carbide and carbonitrid of Ti and Nb are also created.


2013 ◽  
Vol 376 ◽  
pp. 163-172 ◽  
Author(s):  
Mahmoud M. Tash ◽  
S. Alkahtani

The present study was undertaken to investigate the effect of Thermo-mechanical Treatment (TMT) on aging and hardness of Al-Mg-Si (6082) alloys. The effect of cold work after solution treatment, aging time and temperature on the microstructure and hardness were studied. Hardness measurements were carried out on specimens prepared from 6082 alloys in the as solution treated specimens and heat-treated conditions, using different cold work percentage before aging treatment. Aging treatments were carried out for the as solution treated specimens (after quenching in water) as well as for the as cold worked specimens (after solution treatment and quenching in water). The specimens were aged at different conditions; Natural aging was carried out at room temperature for different periods of time. Artificial aging was performed at 100 °C, 150 °C, and 200 °C for various times. It is noticed that cold work, following solution treatment, accelerates the precipitation rate leading to a rise in strength.A statistical design of experiments (DOE) approach using fractional factorial design was applied to determine the influence of controlling variables of cold work and heat treatment parameters and any interactions between them on the hardness of 6082 alloys. A mathematical model is developed to relate the alloy hardness with the different metallurgical parameters i.e. Cold work prior solution heat treatment (CWBSHT), Cold work after solution heat treatment (CWASHT), Pre-aging Temperature (PA T0C), Pre-aging time (PA t h), Aging temperature (AT0C), Aging time (At h), Cold work after aging treatment (CWAAT), Annealing temperature (An.T0C) and Annealing time (An.t min) to acquire an understanding of the effects of these variables and their interactions on the hardness of Al-Mg-Si 6082 alloys.


2018 ◽  
Vol 14 (4) ◽  
pp. 125-132
Author(s):  
Akeel Dhahir Subhi ◽  
Hussein Najim Abdullah

In this work, 332 Al alloy was prepared and reinforced with (0.5% and 1%) nano-Al2O3 particles. The prepared unreinforced and reinforced 332 Al alloy with nano-Al2O3 were solution heat treated (T6) at 510 ̊C and aged at 225 ̊C with different times (1, 3, and 5 h). Hardness test was performed on all the prepared alloys. All prepared alloys were dry slided under different applied loads (5, 10, 15, and 20 N) against steel counterface surface using pin on disk apparatus. The results showed that refinement effect was observed after addition of nano-Al2O3 particles and a change in silicon morphology after performing the solution heat treatment. The results also showed that hardness was increased and the wear rate was decreased with increasing the nano-Al2O3 particles in the matrix of 332 Al-Alloy


2015 ◽  
Vol 819 ◽  
pp. 39-44 ◽  
Author(s):  
Shamsul Baharin Jamaludin ◽  
Mohd Hanif Abdullah ◽  
Mohd Noor Mazlee ◽  
Kamarudin Hussin

This work examines the effect of solution heat treatment temperature on the tensile strength of Al-Mg-Si aluminum alloy. All samples were machined according to the ASTM B557. The samples were solution treated at 450°C and 530°C and followed by ageing at 160°C for 0, 5, 10, 15 and 20 hours. Tensile test was carried out on the samples after heat treatment. The results showed that the highest tensile strengths (201.69 MPa) was given by the sample solution heat treated at 530 °C for 5 hours followed by 20 hours aging at 160 °C. Whereas, the lowest tensile strength (98.52MPa) was given by the sample solution treated at 450°C for 20 hours. Tensile strength was increased with ageing process and decreased for over-aged samples.


2011 ◽  
Vol 339 ◽  
pp. 371-374 ◽  
Author(s):  
Narissara Mahathaninwong ◽  
Sirikul Wisutmethangoon ◽  
Thawatchai Plookphol ◽  
Jessada Wannasin

Influence of temperature and time of solution heat treatment on the microstructures of rheo-casting 7075 aluminium alloy produced by a novel technique, the Gas Induced Semi Solid (GISS) technique, had been investigated in this study. The microstructure of the as-cast specimens mainly consisted of matrix-α (Al) and grain boundary (GB)-eutectic phase (α-Al + Mg(Zn,Cu,Al)2). After solution heat treatment at 480 °C for 1 h, MgZn2 phase at the grain boundary was observed to have dissolved and coarse black particles of Mg2Si were observed to form in the matrix. In comparison, when solutionizing temperature of 450 °C was applied, it took 4 h of solution treatment time in order to dissolve the same portion of GB phase and MgZn2 phase, and coarse black particles of Mg2Si were found to form in the 8 h solution treated sample.


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