Heat Treatments for Aluminum Alloys: When, Why and How

2017 ◽  
Vol 6 (5) ◽  
pp. 20170011 ◽  
Author(s):  
Silvia Lombardo ◽  
Mario Rosso
Keyword(s):  
Aluminum Alloys ◽  
Heat Treatments

The Effect of Heat Treatments and Nickel Additive on The Microstructure and Hardness of 7075 Aluminum Alloy

2019 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
Mahmoud Alasad ◽  
Mohamad Yahya Nefawy
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Artificial Aging ◽  
Heat Treatments ◽  
7075 Aluminum Alloy ◽  
Nickel Additive

The aluminum alloys of the 7xxx series consist of Al with Zn mainly, Mg and Cu. 7xxx aluminum alloys has high mechanical properties making it distinct from other aluminum alloys. In this paper, we examine the effect of adding Nickel and heat treatments on the microstructure and hardness of the 7075 aluminum alloy. Were we added different percentages of nickel [0.1, 0.5, 1] wt% to 7075 Aluminum alloy, and applied various heat treatments (artificial aging T6 and Retrogression and re-aging RRA) on the 7075 alloys that Containing nickel. By applying RRA treatment, we obtained better results than the results obtained by applying T6 treatment, and we obtained the high values of hardness and a smoother microstructure for the studied alloys by the addition of (0.5 wt%) nickel to alloy 7075.

Effect of Electrical Pulsing on Various Heat Treatments of 5XXX Series Aluminum Alloys

2008 ◽  
Author(s):  
Wesley A. Salandro ◽  
Joshua J. Jones ◽  
Timothy A. McNeal ◽  
John T. Roth ◽  
Sung-Tae Hong ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Superplastic Deformation ◽  
Deformation Process ◽  
Electrical Current ◽  
Heat Treatments ◽  
Maximum Deformation ◽  
Aluminum Specimen ◽  
Electrical Pulses ◽  
Minimum Deformation ◽  
Diffuse Neck

Previous studies have shown that the presence of a pulsed electrical current, applied during the deformation process of an aluminum specimen, can significantly improve the formability of the aluminum without heating the metal above its maximum operating temperature range. The research herein extends these findings by examining the effect of electrical pulsing on 5052 and 5083 Aluminum Alloys. Two different parameter sets were used while pulsing three different heat treatments (As Is, 398°C, and 510°C) for each of the two aluminum alloys. For this research, the electrical pulsing is applied to the aluminum while the specimens are deformed, without halting the deformation process. The analysis focuses on establishing the effect the electrical pulsing has on the aluminum alloy’s various heat treatments by examining the displacement of the material throughout the testing region of dogbone shaped specimens. The results from this research show that pulsing significantly increases the maximum achievable elongation of the aluminum (when compared to baseline tests conducted without electrical pulsing). Significantly reducing the engineering flow stress within the material is another beneficial effect produced by electric pulsing. The electrical pulses also cause the aluminum to deform non-uniformly, such that the material exhibits a diffuse neck where the minimum deformation occurs near the ends of the specimen (near the clamps) and the maximum deformation occurs near the center of the specimen (where fracture ultimately occurs). This diffuse necking effect is similar to what can be experienced during superplastic deformation. However, when comparing the presence of a diffuse neck in this research, electrical pulsing does not create as significant of a diffuse neck as superplastic deformation. Electrical pulsing has the potential to be more efficient than traditional methods of incremental forming since the deformation process is never interrupted. Overall, with the greater elongation and lower stress, the aluminum can be deformed quicker, easier, and to a greater extent than is currently possible.

Microstructure and Mechanical Properties of Three-Layer TIG-Welded 2219 Aluminum Alloys with Dissimilar Heat Treatments

2018 ◽  
Vol 27 (6) ◽  
pp. 2938-2948 ◽  
Author(s):  
Dengkui Zhang ◽  
Quan Li ◽  
Yue Zhao ◽  
Xianli Liu ◽  
Jianling Song ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Heat Treatments ◽  
Microstructure And Mechanical Properties

The Effect of Microalloying of Nickel, RRA Treatment on Microstructure and Mechanical Properties for High Strength Aluminum Alloy

2014 ◽  
Vol 925 ◽  
pp. 253-257 ◽  
Author(s):  
Haider T. Naeem ◽  
Kahtan S. Mohammad ◽  
Khairel R. Ahmad
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
High Strength ◽  
Casting Process ◽  
Direct Chill ◽  
Heat Treatments ◽  
Alloy Sample ◽  
Retrogression And Reaging ◽  
High Strength Aluminum Alloys ◽  
Direct Chill Casting Process

High strength aluminum alloys Al-Zn-Mg-Cu-(0.1) Ni produced by semi-direct chill casting process were homogenized at different conditions then conducted heat treatment process which comprised pre-aging at 120°C for 24 h, retrogression at 180°C for 30 min, and then re-aging at 120°C for 24 h. Microstructural studies showed that add Ni (0.1 wt %) to the alloy will be forming Ni-rich phases such as AlCuNi, AlNi, AlNiFe and AlMgNi which provide a dispersive strengthening affected in the solid-solution and the subsequent heat treatments. The results showed that by this three-step process of heat treatments, the mechanical properties of aluminum alloys Al-Zn-Mg-Cu-(0.1) Ni were substantially improved. The highest attain for the ultimate tensile strength and Vickers hardness for the alloy sample after applied the retrogression and reaging process is about 545 MPa and 237 HV respectively.

Formability of Al 5xxx Sheet Metals Using Pulsed Current for Various Heat Treatments

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Wesley A. Salandro ◽  
Joshua J. Jones ◽  
Timothy A. McNeal ◽  
John T. Roth ◽  
Sung-Tae Hong ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Superplastic Deformation ◽  
Deformation Process ◽  
Electrical Current ◽  
Heat Treatments ◽  
Maximum Deformation ◽  
Aluminum Specimen ◽  
Electrical Pulses ◽  
Minimum Deformation ◽  
Diffuse Neck

Previous studies have shown that the presence of a pulsed electrical current, applied during the deformation process of an aluminum specimen, can significantly improve the formability of the aluminum without heating the metal above its maximum operating temperature range. The research herein extends these findings by examining the effect of electrical pulsing on 5052 and 5083 aluminum alloys. Two different parameter sets were used while pulsing three different heat-treatments (as-is, 398°C, and 510°C) for each of the two aluminum alloys. For this research, the electrical pulsing is applied to the aluminum while the specimens are deformed without halting the deformation process (a manufacturing technique known as electrically assisted manufacturing). The analysis focuses on establishing the effect of the electrical pulsing has on the aluminum alloy’s various heat-treatments by examining the displacement of the material throughout the testing region of dogbone-shaped specimens. The results from this research show that pulsing significantly increases the maximum achievable elongation of the aluminum (when compared with baseline tests conducted without electrical pulsing). Another beneficial effect produced by electrical pulsing is that the engineering flow stress within the material is considerably reduced. The electrical pulses also cause the aluminum to deform nonuniformly, such that the material exhibits a diffuse neck where the minimum deformation occurs near the ends of the specimen (near the clamps) and the maximum deformation occurs near the center of the specimen (where fracture ultimately occurs). This diffuse necking effect is similar to what can be experienced during superplastic deformation. However, when comparing the presence of a diffuse neck in this research, electrical pulsing does not create as significant of a diffuse neck as superplastic deformation. Electrical pulsing has the potential to be more efficient than the traditional methods of incremental forming since the deformation process is never interrupted. Overall, with the greater elongation and lower stress, the aluminum can be deformed quicker, easier, and to a greater extent than is currently possible.

Service Life Aging and Heat Exposure Effects on Aluminum Sheet Alloy Properties and Structural Crashworthiness Under Dynamic Axial Loading

2005 ◽  
Author(s):  
Ridha Baccouche ◽  
David Wagner ◽  
Andy Sherman ◽  
Craig Miller ◽  
Susan Ward ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Service Life ◽  
Energy Management ◽  
Heat Exposure ◽  
Heat Treatments ◽  
Aluminum Sheet ◽  
Time Data ◽  
Sheet Aluminum ◽  
The Mean ◽  
Alloy Properties

An investigation of the service life aging and heat exposure effects on sheet aluminum alloy properties and structural crashworthiness has been conducted. This research, part of a broader program, consists of investigating five aluminum sheet alloys each of which is subjected to four heat treatments. The aluminum sheet alloys investigated are 6111T4PD, 5754-O, 5182-O, 6022T4E29, and 6022T4. The four heat treatments are 177°C for 30 minutes, 200°C for 15 minutes, 200°C for 2 hours, and 200°C for 24 hours. The 200°C/24 hours treatment simulates the most severe thermal exposure i.e. components adjacent to exhaust pipes and manifolds. All 200°C heat treatments are in addition to the 177°C for 30 minutes. All specimens were subjected to the reference 177°C for 30 minutes treatment. Aluminum rails of hexagonal cross-section were formed for the twenty combinations of aluminum sheet alloys and heat exposures. These twenty formed aluminum rails were then bonded and riveted using Betamate 4601 adhesive and Henrob K50742 self-piercing rivets. Once assembled, these twenty rails were subjected to dynamic axial crushing at a speed of 40 kph (25 mph). Force-Time data was collected and responses were plotted for all tests. Force-Displacement responses were then integrated for the crush energy management and mean axial crush load for each of the aluminum sheet rails. Bar charts were generated to describe the crash loads and energy management behaviors of the various aluminum alloys and associated heat treatments. Service life simulated heat exposure was found to affect the mean crash load and crash energy management of the aluminum structural crash members. The heat exposure effects on the crashworthiness of the sheet aluminum members ranged from a reduction of [−21.6%] to an increase of [+6.8%] in the mean crash load and crash energy management with higher variation observed in the “T4” tempered aluminum alloys.

The Role of Zirconium Additions in Recrystallization of Aluminum Alloys

2007 ◽  
Vol 558-559 ◽  
pp. 383-387 ◽  
Author(s):  
Hasso Weiland ◽  
Soon Wuk Cheong
Keyword(s):  
Grain Size ◽  
Aluminum Alloys ◽  
Grain Boundary ◽  
Solute Drag ◽  
Heat Treatments ◽  
Boundary Mobility ◽  
Grain Boundary Mobility ◽  
Structural Applications ◽  
Zn Alloys

Control of grain size during recrystallization of aluminum alloys is critical when tailoring material properties for structural applications. Most commonly the grain size is controlled by adding alloying elements which form second phases during homogenization heat treatments small enough to impose a Zener drag on the grain boundary mobility. These phases are known as dispersoids and are in the 10 to 200 nm in diameter range. In Al-Zn alloys, zirconium has been successfully used in controlling the degree of recrystallization after solution heat treatments. It is commonly understood that the Al3Zr dispersoids of about 20 nm in diameter present in the microstructure are the key features affecting grain boundary mobility. With the success of controlling recrystallization in Al- Zn alloys, zirconium has been added to other alloy systems, such as Al-Cu-Mn, and a similar retarding effect in recrystallization kinetics has been observed as seen in the Al-Zn systems. However, in Al-Cu-Mn alloys, zirconium bearing dispersoids are not observable in the microstructure. Consequently, additional microstructural effects such as solute drag need to be considered to explain the experimental observations. In this paper, the role of zirconium additions in aluminum alloys will be summarized.

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