Evolution of the Retrogression and Reaging Treatment on Microstructure and Properties of Aluminum Alloy (Al-Zn-Mg-Cu)

2014 ◽  
Vol 925 ◽  
pp. 258-262 ◽  
Author(s):  
Haider T. Naeem ◽  
Khairul R. Ahmad ◽  
Kahtan S. Mohammad ◽  
Azmi Rahmat
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Treatment Process ◽  
Casting Process ◽  
Direct Chill ◽  
Cu Alloys ◽  
Treatment Conditions ◽  
Retrogression And Reaging ◽  
Aa 7075 ◽  
Dc Casting

In this study the evolution of the retrogression and reaging (RRA) heat treatment process on microstructure and mechanical properties of AA 7075 Al-alloys which produced by semi-direct chill (DC) casting process were investigated. Al-Zn-Mg-Cu alloys were homogenized at different heat treatment conditions, aged at 120°C for 24 h (T6), and retrogressed at 180°C for 30 min then re-aged at 120°C for 24 h (RRA). The results showed that this three-step process of the heat treatments, the mechanical properties of alloys was substantially improved. The highest ultimate tensile strength and Vickers hardness attained for the retrogression and re-aging about 530 MPa and 223 HV respectively. The precipitation strengthening is responsible about improve the strength under impact the retrogression and re-aging process.

Application Research of a New Coupling Stirring on DC Casting Process for Large-Sized Aluminum Ingots

2015 ◽  
Vol 817 ◽  
pp. 48-54 ◽  
Author(s):  
Hai Jun Wang ◽  
Jun Xu ◽  
Zhi Feng Zhang ◽  
Bo Liang ◽  
Ming Wei Gao
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Casting Process ◽  
Direct Chill ◽  
Application Research ◽  
Center Position ◽  
Composition Segregation ◽  
Dc Casting ◽  
The Difference ◽  
7075 Alloy

A new coupling stirring technology was proposed and used to prepare direct chill (DC) ingots. Ingots of 7075 alloy were produced by a process of normal direct chill (NDC) casting and coupling-stirring direct chill (CDC) casting, respectively. The effect of the technology on the microstructures, composition segregation and mechanical properties of the ingots was investigated. The results showed that the temperature variation in the CDC casting process was more uniform than that in the NDC casting process. The grain of the CDC ingots was finer and more spherical than the grain of NDC ingots. The grain size at the edge, 1/2 radius, and center position in CDC ingot decrease by 28%, 22%, and 24% comparing with the grain size of the corresponding positions of NDC ingot, respectively. The billets with higher performance and lower macro-segregation were obtained in case of CDC. The flow stresses and the difference in different positions of DC ingots measured at Gleeble-1500D thermo-mechanical simulator decreased obviously when the coupling stirring technology is used in the casting process.

Preparation and Evaluation of a Novel Al-5.4Si-0.5Mg Welding Wire

2014 ◽  
Vol 788 ◽  
pp. 176-181
Author(s):  
Hao Wang ◽  
Chang Shu He ◽  
Dong Wang ◽  
Xiang Zhao ◽  
Liang Zuo
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Arc Welding ◽  
Aging Treatment ◽  
Direct Chill ◽  
The Novel ◽  
Welding Wire ◽  
Treatment Conditions ◽  
Dc Casting ◽  
Preparation And Evaluation

An Al-5.4Si-0.5Mg filler wire was developed and produced by direct chill (DC) casting, extrusion, and roll-die and hole-die drawing for the welding of newly developed Mg-containing high-Si aluminum alloys. The Al-12.7Si-0.7Mg alloy plates were butt-welded by tungsten inert gas arc welding (TIG) method using the as-produced welding wire. The microstructures and mechanical properties of these welded joints in different solid solution and artificial aging treatment conditions were studied to evaluate the weld qualities of the novel welding wire. The results showed that the Al-5.4Si-0.5Mg welding wire was an ideal special welding wire of the Al-12.7Si-0.7Mg alloy and the filler metal proved to be heat-treatable. The welded joints exhibited much higher mechanical properties after the post-weld heat treatment (PWHT). All of this provides the possibility of wide application of the novel Al-5.4Si-0.5Mg welding wire and the Al-12.7Si-0.7Mg alloy weldments.

Effects of Heat Treatment on the Mechanical and Tribological Properties of Aluminium (LM6) Reinforced with Iron Oxide (Fe2O3)

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
J. Arun Prakash ◽  
P. Shanmughasundaram ◽  
M. Vemburaj ◽  
P. Gowtham
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Iron Oxide ◽  
Treatment Process ◽  
Casting Process ◽  
Stir Casting ◽  
Heat Treatment Process ◽  
Treatment Results ◽  
Mechanical And Tribological Properties

This work deals with the examination of the mechanical properties of Aluminium (LM6) reinforced with iron oxide (Fe2O3). Stir casting process is used to formulate the composite sampling by varying iron oxide in 5% and 10% by weight. Three different heat treatment process of hardening, annealing and normalizing is carried out on samples of aluminium (LM6), aluminium (LM6) + 5% Fe2O3 and aluminium (LM6) + 10% Fe2O3. Composite specimens are tested to analyze the mechanical properties such as hardness, yield stress, tensile strength and elongation. Present reinforcement specks enabled the alloy to preserve higher hardness during the heat treatment. Results have shown substantial improvements in properties of the specimens with various compositions of reinforcement.

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.

Effect of Direct Chill Casting Speed and Heat Treatment on Microstructure and Mechanical Properties of Al-13.9%Mg2Si Composite

2016 ◽  
Vol 877 ◽  
pp. 15-19
Author(s):  
Dong Tao Wang ◽  
Hai Tao Zhang ◽  
Ke Qin ◽  
Xing Han ◽  
Bo Shao ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Casting Speed ◽  
Solution Heat Treatment ◽  
Casting Process ◽  
Direct Chill ◽  
Round Shape ◽  
Sharp Edges ◽  
Dc Casting

The aim of this work is to investigate the effect of different casting speed in DC casting process and solution heat treatment of in situ Al-13.9%Mg2Si composite. The increasing of DC casting speed not only makes primary Mg2Si distribute more uniform and restricts segregation of primary Mg2Si particles, but also it reduces primary Mg2Si particle size. The DC casting speed significantly alter the eutectic Mg2Si phase from fibrous to fine dot-like and eutectic phase refines effectively. The results obtained from mechanical testing demonstrated that the increasing of DC casting speed intensifies both hardness and tensile strength values. Then, the billet were subjected to solutionizing at 500oC for holding time of 4h followed by quenching. The results indicate that the morphology of both primary and eutectic Mg2Si changes after heat treatment. Solutionizing leads to the dissolution of the Mg2Si particles and changes morphology from sharp edges to round shape. After solution heat treatment, tensile strength and elongation increase to 238.8MPa and 13.5%.

The Role of Direct Chilling, Retrogression and Reaging Treatment on Mechanical Properties of High Strength Aluminum Alloy

2013 ◽  
Vol 795 ◽  
pp. 211-218 ◽  
Author(s):  
Haider T. Naeem ◽  
Kahtan S. Mohammed ◽  
R.A. Khairel ◽  
Azmi Rahmat
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Strength ◽  
Casting Process ◽  
Al Alloy ◽  
Average Value ◽  
Uniform Microstructure ◽  
Hardness Tests ◽  
Retrogression And Reaging

The effect of retrogression and reaging heat treatment on microstructure evolution andmechanical properties of 7075 Al alloy in direct chilling casting process was investigated. The subsequent heat treatment process comprised pre-aging at 120°C for 24 h, retrogression at 180°C for 30 min, and then reaging at 120°C for 24 h. By this three-step process, the mechanical properties of the chilled casted samples were substantially improved. The samples retain their high strength at T6 level. They gave yield strength up to 290 MPa, ultimate tensile strength of 386 MPa and elongation of 5.9%. The average value of multiple Vickers hardness tests results were in the range of 210 Hv. The direct chilling process followed by retrogression and reaging heat treatment yielded casts of fine and uniform microstructure as opposed to the microstructure of samples casted by the conventional process.

Mechanical Properties and Constitutive Behavior of as-Cast High Strength AA7xxx Alloys below Solidus Temperature

2014 ◽  
Vol 794-796 ◽  
pp. 467-472 ◽  
Author(s):  
Qing Ling Bai ◽  
Hong Xiang Li ◽  
Qiang Du ◽  
Ji Shan Zhang ◽  
Lin Zhong Zhuang
Keyword(s):  
Mechanical Properties ◽  
Solidus Temperature ◽  
High Strength ◽  
Casting Process ◽  
Direct Chill ◽  
Mechanical Analysis ◽  
Fine Tuning ◽  
Stress Strain ◽  
Strain Behavior ◽  
Dc Casting

High strength AA7xxx alloys have been extensively used in aerospace industry. However, experience in cast house demonstrates that such alloys are particularly prone to cold cracking and ingot distortion during direct chill (DC) casting, which leads to big amount of scraping or even total rejection of ingot. Those stress induced defects are greatly affected by casting process, and fine tuning of casting parameters is critical to improve the quality and productivity. Recently, numerical modeling has been widely utilized in direct-chill casting for the purpose of thermal mechanical analysis and cracking evaluation. Parameter optimization has become convenient. The model needs the input of constitutive properties of the AA7xxx alloys, of which the microstructure should resemble those formed during DC casting. Unfortunately, these constitutive data are not yet available in literatures. In this study, the mechanical properties of two high strength AA7xxx alloys were measured at temperature range from solidus down to room temperature through on-cooling compressive tests and the effect of strain rate on stress-strain behavior was also studied. The results were fitted to extended Ludwik equation which has been proved to be able to properly describe the stress-strain response of aluminum alloys. The results of the current work shed some light on the evolution of mechanical behavior of high strength AA7xxx alloys during cooling from high temperature.

Effects of Nano Particles on the Microstructure of LM 25 (A356) Alloy Manufactured by Squeeze Casting

2017 ◽  
Vol 867 ◽  
pp. 64-70
Author(s):  
N. Nagendran ◽  
N. Gayathri ◽  
V.K. Shanmuganathan ◽  
S. Praveen
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Treatment Process ◽  
Squeeze Casting ◽  
Casting Process ◽  
Nano Particles ◽  
Heat Treatment Process ◽  
Cast Part ◽  
Heat Treated ◽  
Squeeze Casting Process

Conventional casting process cannot produce parts as strong as forged parts. Also there are chances of many casting defects such as porosity, hot tears, shrinkage, pin holes, blow holes, mould shift flash, slag, short casting, when casting method is used for fabrication. Thus cast parts only have low mechanical properties. Recent trend is to use Squeeze Casting, which results in superior mechanical and casting properties. This technique is a hybrid metal forming process combining features of both casting and forging in one operation. This process is suitable for low melting alloys like iron and nickel with mechanical properties enhancement. Reduction in micro porosity in cast part and also reduction in machining. Historically, the series of LM were developed for high strength, corrosion resistance, and good machinability for many applications. In this study Squeeze Casting process has been used, since it has porosity free equiaxed grain components of LM 25 composition and cylindrical shaped castings were manufactured successfully by squeeze casting machine at high temperature and high pressure. The first part of the study is about the microstructure of the LM 25 Al-7 Si-0.3 Mg-0.5 Fe alloy. The casting products were made by addition of nano particles and without nano particles. The size of bar casted was by squeeze casting process. It was 260 mm*46mm (7 Pieces). Microstructure of Cast without squeeze and without stirrer, without squeeze and with stirrer, with squeeze and with stirrer Alloys was studied. The second part of the work was the heat treatment process of the finished product. Heat treatment process was conducted at 490○C and for the heat treated metals was quenched at 30○C (water) for the heat treated and unheated metal casting product were taken and microstructure were studied. The results were compared before and after the heat treatment process for addition of nano particles and without nano particles.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

scholarly journals Achievement of High Strength and Ductility in Al–Si–Cu–Mg Alloys by Intermediate Phase Optimization in As-Cast and Heat Treatment Conditions

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 647 ◽  
Author(s):  
Bingrong Zhang ◽  
Lingkun Zhang ◽  
Zhiming Wang ◽  
Anjiang Gao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Intermediate Phase ◽  
High Strength ◽  
Mg Alloys ◽  
Artificial Ageing ◽  
Treatment Conditions ◽  
Eutectic Si

In order to obtain high-strength and high-ductility Al–Si–Cu–Mg alloys, the present research is focused on optimizing the composition of soluble phases, the structure and morphology of insoluble phases, and artificial ageing processes. The results show that the best matches, 0.4 wt% Mg and 1.2 wt% Cu in the Al–9Si alloy, avoided the toxic effect of the blocky Al2Cu on the mechanical properties of the alloy. The addition of 0.6 wt% Zn modified the morphology of eutectic Si from coarse particles to fine fibrous particles and the texture of Fe-rich phases from acicular β-Fe to blocky π-Fe in the Al–9Si–1.2Cu–0.4Mg-based alloy. With the optimization of the heat treatment parameters, the spherical eutectic Si and the fully fused β-Fe dramatically improved the ultimate tensile strength and elongation to fracture. Compared with the Al–9Si–1.2Cu–0.4Mg-based alloy, the 0.6 wt% Zn modified alloy not only increased the ultimate tensile strength and elongation to fracture of peak ageing but also reduced the time of peak ageing. The following improved combination of higher tensile strength and higher elongation was achieved for 0.6 wt% Zn modified alloy by double-stage ageing: 100 °C × 3 h + 180 °C × 7 h, with mechanical properties of ultimate tensile strength (UTS) of ~371 MPa, yield strength (YS) of ~291 MPa, and elongation to fracture (E%) of ~5.6%.

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