scholarly journals Hot Extrusion Enhanced Homogenization of Microstructure in a Spray Deposition Aluminum Alloy

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 263
Author(s):  
Xiaofei Sheng ◽  
Yong Yang ◽  
Hongchun Yu ◽  
Wenke Wu ◽  
Kai Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Treatment Time ◽  
Spray Deposition ◽  
Hot Extrusion ◽  
Stored Energy ◽  
Homogeneous Microstructure ◽  
Area Reduction ◽  
Equiaxed Grains

Homogeneous heat treatment serves the significant roles in eliminating the segregation and tuning the microstructure of alloy ingot. It usually cost tremendous power and time to achieve a homogeneous microstructure for aluminum alloys. In this article, the hot extrusion was directly introduced on the spray deposited aluminum alloy 7055 ingot before performing heat treatment to explore the newly feasible homogeneous routine. Equiaxed grains without dendrites or PPB were obtained in our current parameters of spray deposition, which allowed the as-deposited alloy to be deformed without being subjected to pre-homogeneous heat treatment. Significant amount of stored energy was produced during hot extrusion at 420 °C with area reduction ratio of 6.25, which effectively promoted the homogeneity of microstructure and reduced significantly the heat treatment time. A newly feasible short routine, heat treatment at 450 °C /6 h + 470 °C/1 h following the hot extrusion, proved capable of obtaining a homogeneous microstructure for the spray deposited aluminum alloy 7055.

scholarly journals Monitoring of Thermal Aging of Aluminum Alloy via Nonlinear Propagation of Acoustic Pulses Generated and Detected by Lasers

2019 ◽  
Vol 9 (6) ◽  
pp. 1191 ◽  
Author(s):  
Mengmeng Li ◽  
Alexey Lomonosov ◽  
Zhonghua Shen ◽  
Hogeon Seo ◽  
Kyung-Young Jhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Yield Strength ◽  
Thermal Aging ◽  
Finite Amplitude ◽  
Quadratic Nonlinearity ◽  
Laser Ultrasonic ◽  
Ultrasonic Techniques ◽  
Non Destructive

Nonlinear acoustic techniques are established tools for the characterization of micro-inhomogeneous materials with higher sensitivity, compared to linear ultrasonic techniques. In particular, the evaluation of material elastic quadratic nonlinearity via the detection of the second harmonic generation by acoustic waves is known to provide an assessment of the state variation of heat treated micro-structured materials. We report on the first application for non-destructive diagnostics of material thermal aging of finite-amplitude longitudinal acoustic pulses generated and detected by lasers. Finite-amplitude longitudinal pulses were launched in aluminum alloy samples by deposited liquid-suspended carbon particles layer irradiated by a nanosecond laser source. An out-of-plane displacement at the epicenter of the opposite sample surface was measured by an interferometer. This laser ultrasonic technique provided an opportunity to study the propagation in aluminum alloys of finite-amplitude acoustic pulses with a strain up to 5 × 10−3. The experiments revealed a signature of the hysteretic quadratic nonlinearity of micro-structured material manifested in an increase of the duration of detected acoustic pulses with an increase of their amplitude. The parameter of the hysteretic quadratic nonlinearity of the aluminum alloy (Al6061) was found to be of the order of 100 and to exhibit more than 50% variations in the process of the alloy thermal aging. By comparing the measured parameter of the hysteretic quadratic nonlinearity in aluminum alloys that were subjected to heat-treatment at 220 °C for different times (0 min, 20 min, 40 min, 1 h, 2 h, 10 h, 100 h, and 1000 h), with measurements of yield strength in same samples, it was established that the extrema in the dependence of the hysteretic nonlinearity and of the yield strength of this alloy on heat treatment time are correlated. This experimental observation provides the background for future research with the application goal of suggested nonlinear laser ultrasonic techniques for non-destructive evaluation of alloys’ strength and rigidity in the process of their heat treatment.

scholarly journals EN AW-2024 Wrought Aluminum Alloy Processed by Casting with Crystallization under Pressure

2017 ◽  
Vol 67 (2) ◽  
pp. 109-116
Author(s):  
Branislav Vanko ◽  
Ladislav Stanček ◽  
Roman Moravčík
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Shrinkage Porosity ◽  
Forced Flow ◽  
Heat Treated ◽  
Crystallization Under Pressure ◽  
Wrought Aluminum Alloys ◽  
Wrought Aluminum

AbstractBy using the wrought aluminum alloys can be created castings with higher mechanical properties than the castings made of standard foundry aluminum alloys, but it is necessary to handle the process of making sound castings without any defects such as hot tears and shrinkage porosity. In experiments, we have been studied of wrought aluminum alloy EN AW-2024 which has been processed by the casting with crystallization under pressure with forced flow. Castings were heat treated by standard T6 heat treatment.

scholarly journals Electrical Resistivity and Tensile Strength Relationship in Heat-Treated All Aluminum Alloy Wire Conductors

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5738
Author(s):  
Nidal Alshwawreh ◽  
Baider Alhamarneh ◽  
Qutaiba Altwarah ◽  
Shamel Quandour ◽  
Shadi Barghout ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Electrical Resistivity ◽  
Aluminum Alloy ◽  
Mechanical Strength ◽  
High Performance ◽  
Treatment Time ◽  
Treatment Temperature ◽  
Exponential Relationship ◽  
And Control

Thermal processing of all aluminum alloy conductors (AAAC) is an important step that is performed to enhance the electrical and mechanical properties after the drawing process. In these 6xxx alloys, mechanical strength and electrical conductivity are normally two mutually exclusive properties. With the increased demand for high performance power conductors, it is important to understand and control microstructural evolution processes (e.g., recovery and the formation of nanoscale precipitates) in these alloys for better electrical and mechanical characteristics. In this study, heat treatment was performed on as-drawn 6201 AAAC wire conductors. The variations in tensile strength and electrical resistivity were quantitatively studied as a function of both the treatment temperature and holding time. Two wire diameters commonly used in the manufacturing of medium and high voltage power cables were used: 1.7 mm and 3.5 mm. From the obtained data, significant changes in the electrical resistivity and tensile strength were observed with increasing the treatment time. For both wire diameters, it was observed that the correlation between strength and resistivity can be described by a simple exponential relationship. This link could be useful in predicting mechanical strength by monitoring electrical resistivity variations during industrial heat treatment of AAAC wire conductors.

scholarly journals Improving of Surface Quality of Metal Reflector Mirrors Machined by Single Point Diamond Turning

2021 ◽  
Vol 12 (2) ◽  
pp. 139-145
Author(s):  
G. A. Gusakov ◽  
G. V. Sharonov
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Surface Treatment ◽  
Radiation Resistance ◽  
Single Point ◽  
Diamond Turning ◽  
Laser Damage Threshold ◽  
Complete Disappearance

Improving the technology of diamond turning of aluminum alloys is of great importance for expanding the application areas of metal-optical products based on aluminum in aerospace technology. The aim of this work was to study the effect of surface inhomogeneities of the initial aluminum alloy substrates on their optical and mechanical characteristics and to determine ways of improving the quality of aluminum reflector mirrors manufactured using nanoscale single point diamond turning. The investigated reflector mirrors were made from AMg2 aluminum alloy. The optical surface treatment was carried out on a precision turning lathe with an air bearing spindle using a special diamond cutter with a blade radius of ≤ 0.05 μm. The analysis of the surface structure of the AMg2 alloy substrates was carried out by scanning electron microscopy / electron microprobe. The quality control of the surface treatment of the manufactured reflector mirrors was carried out by atomic force microscopy. The reflectivity and radiation resistance of these samples were also investigated.It is shown that an important problem in the manufacture of optical elements from aluminum alloys is the inhomogeneity of the structure of the initial material, associated with the presence of intermetallic inclusions. Heat treatment of the AMg2 alloy substrates at T ≥ 380 °C makes it possible to improve the quality of surface and the radiation resistance of aluminum mirrors both by removing mechanical stresses and by partially homogenizing the starting material. The optimum is heat treatment at the maximum allowable temperature for the AMg2 alloy T = 540 ºС, as a result of which there is a complete disappearance of intermetallic inclusions with an increased magnesium content. The use of high-temperature heat treatment of AMg2 alloy substrates allows, in comparison with unannealed samples, to reduce the surface roughness from 1.5 to 0.55 nm, to increase the reflectivity of mirrors at a wavelength of 1064 nm from 0.89 to 0.92, and to increase the laser damage threshold from 3.5 to 5 J / cm2.

Tensile Properties and Microstructure of Friction Stir Welded Joints 2195-T8 Aluminum Alloy

2016 ◽  
Vol 835 ◽  
pp. 191-196 ◽  
Author(s):  
Kookil No ◽  
Ye Rim Lee ◽  
Jong Hoon Yoon ◽  
Joon Tae Yoo ◽  
Ho Sung Lee
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Welding Process ◽  
Tensile Tests ◽  
Fusion Welding ◽  
Homogeneous Microstructure ◽  
Rotating Speed ◽  
Friction Stir ◽  
Reactive Property

Friction stir welding is a widely used welding process for aluminum alloys because it avoids many of the problems of conventional fusion welding. This process is beneficial especially for lithium containing aluminum alloys in which the reactive property of element Li causes porosity and hot cracking during melting and solidification. In friction stir welding process, each region undergoes different thermo-mechanical cycles and produces a non-homogeneous microstructure. In the present study, the mechanical properties and microstructure of a 2195-T8 aluminum alloy joined with friction stir welding were investigated. The change in microstructure across the welded joint was found to correspond to microhardness measurement. The microstructure was characterized by the presence of severely deformed grains and fine recrystallized grains depending on the region. Tensile tests shows the optimum condition was obtained at the tool rotating speed of 600rpm and the traveling speed range from 180 to 300mm/min.

Wrought Aluminum Alloy: Reinforcement, Alloy Addition, and Deformation Effects on Mechanical Responses

2019 ◽  
Author(s):  
Samson Oluropo Adeosun ◽  
E. I. Akpan ◽  
S. A. Balogun
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Silicon Carbide ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Good Prospect ◽  
Reinforcing Particles ◽  
Alloy Addition ◽  
Wrought Aluminum Alloys ◽  
Wrought Aluminum

This article discusses the effects of various modifications on the properties of aluminum alloys for structural applications. The effect of reinforcing particles on the mechanical properties of wrought 6063 aluminum alloy arising from our previous works is extensively discussed to identify the most promising reinforcing particles. It also discusses the improvement in mechanical properties of 1200 aluminum alloy using silicon carbide particulates. The effect of micro-alloy additions on the mechanical properties is also outlined in this article based on the results from our previous experimental works. Effect of combining heat treatment and deformation on the mechanical properties of wrought aluminum alloys is also presented. Results presented show that particle reinforcement, deformation, and microelemental additions to aluminum alloy result in significant improvement in mechanical properties of the alloys considered. Addition of reinforcing particles of barite, silicon carbide, iron fillings, and electric arc furnace dust are found to impart improved tensile strength to aluminum alloy. The most outstanding finding is that synergy between particle addition, deformation, and heat treatment has a good prospect in the production of improved aluminum alloy materials for automotive applications.

scholarly journals Application of Pressure Treatment Methods for Solid Processing of Silumin Chip Waste

2020 ◽  
Author(s):  
Nikolay Zagirov ◽  
Yuri Loginov ◽  
Evgeniy Ivanov ◽  
Rinat Rizakhanov
Keyword(s):  
Heat Treatment ◽  
Relative Elongation ◽  
Hot Extrusion ◽  
Waste Processing ◽  
Pressure Treatment ◽  
Processing Waste ◽  
Area Reduction ◽  
Silicon System ◽  
Overall Effectiveness ◽  
Metal Melting

n this article various technological schemes for processing waste in the form of chips of an alloy of an aluminum-silicon system are presented. It was noted that the processing of fine waste of the chips type is always accompanied by oxidation of the metal due to the large surface of contact with the air. To eliminate the loss of metal into oxides during re-melting, this study proposes processing chips by pressing to obtain briquettes (a method of hot extrusion is meant by ‘pressing’). Processing involves the receipt of briquettes from rods. The processes of cold and hot briquetting were undertaken separately. The results of applying the scheme using real production waste are presented in this study. The tensile strength achieved was up to 270 MPa. The relative elongation to rupture was 10–25% and the area reduction after rupture was 25–45%. There were no large differences in the use of briquettes obtained by cold processing and hot processing. The conclusion is drawn about the overall effectiveness of the application of the waste processing without the use of the metal melting. Keywords: silumin, shavings, extrusion, plastic deformation, heat treatment

Effect of Heat Treatment Conditions on Tube Hydroforming Characteristics of Aluminum Alloy

2013 ◽  
Vol 535-536 ◽  
pp. 275-278
Author(s):  
Myeong Han Lee ◽  
Young Chul Shin ◽  
Duk Jae Yoon
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Treatment Processes ◽  
Forming Technology ◽  
Treatment Conditions ◽  
Compressive Loads ◽  
Hydroforming Process

Tube hydroforming is a metal forming technology that utilizes internal pressure and axial compressive loads to generate designed product shapes with complex sections from tubular materials. The tube hydroforming process has been used in the automotive, aircraft, and bicycle industries for many years. With the pursuit of lighter bicycles, aluminum alloys have been utilized as an alternative to steel. To obtain adequate strength, the aluminum alloys should undergo heat treatment processes before being used. However, the mechanical properties of the alloys vary with the tempering conditions. This paper aims to evaluate the effects of tube hydroforming characteristics on different kinds of tempered aluminum alloys. Based on numerical simulations, suitable tube hydroforming processing conditions for each tempered aluminum alloy are suggested.

Intermediate Heat Treatment – A New Proceeding for Aluminum Alloys Using Forming Limit Diagrams

2011 ◽  
Vol 473 ◽  
pp. 428-435 ◽  
Author(s):  
Kathleen Siefert ◽  
Marion Merklein ◽  
Almut Töpperwien ◽  
Winfried Nester ◽  
Martin Grünbaum
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Strain Hardening ◽  
Room Temperature ◽  
Forming Limit ◽  
Cold Forming ◽  
Intermediate Heat Treatment ◽  
Heat Treated ◽  
Strain Paths

This paper presents a new procedure for a heat treatment embedded between two cold forming steps. A first cold forming step induces a defined strain hardening in the material. The following step is the heat treatment which takes place in a furnace at various temperatures and for certain durations. The application of such an intermediate heat treatment reduces the strain hardening of the material and enhances the elongation. This allows a higher degree of deformation in the second cold forming operation. The achievable properties of the aluminum alloy AlMg4.5Mn (AA5182) were discussed in detail. Further investigations using Nakajima test setup revealed an increased formability of the material. First the Nakajima samples were pre-strained along different linear strain paths to a predefined strain value. Afterwards the samples were heat treated without allowing the aluminum alloy to recrystallize. After cooling down the samples to room temperature, the tests are continued until the material’s fracture. As a result heat treatment dependent forming limit curves (FLC) are obtained. In comparison with a measured FLC at room temperature the support of the intermediate heat treatment on enhanced formability were shown. Furthermore the method is not restricted to AA5182 aluminum alloys.

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