Showing 31 results for Aluminum
Dr. Seyedeh Zahra Anvari, Eng. Meysam Khandozi,
Volume 7, Issue 2 (1-2022)
Abstract
In the present study, to resolve the problems in fusion welding methods as well as to increase the strength, FSW method was used to join aluminum alloy sheets 6061 and 2024. Moreover, optimal parameters for joining of these two alloys were also taken into consideration. Various tool rotation speeds of 565, 950 and 1500 rpm were selected. For each tool rotation speed, two traverse speed variables, two penetration depth variables, and two tool angle variables were specified. The analysis of mechanical properties of welded samples was conducted through tensile and micro-hardness tests. Furthermore, microstructure of welding zone was investigated using optical and electron microscopes. The ratio of shoulder diameter to pin diameter is among the most significant and practical factors for welding tools. So, a shoulder diameter three times larger than that of pin diameter was selected. In the present study, alloy 2024 was placed at the precursor as the harder alloy. Tensile strength and indentation hardness of optimal specimen 300 MPa and 85 HV were achieved. Moreover, hardness behavior and tensile strength of heat-affected zone (HAZ) was evaluated to be lower in alloy 6061 compared to other zones.
M. Foumani, H. Naffakh-Moosavy, A. Rasouli, H. Aliyari,
Volume 8, Issue 1 (8-2022)
Abstract
Surface roughness in the welding processes is one of the important parameters in the laser welded metal connections which affects laser beam absorption directly. When the laser beam is irradiated to the surface of the base metal, the surface roughness plays an important role in the amount of beam absorption and the amount of melting achieved and directly affects the penetration depth. The main purpose of this study is to investigate the effect of roughness mentioned above in the equal parameter for this widely used aluminum alloy. Microstructural Surveys were performed on three different roughness levels of the sample and the results obtained from the analysis of samples by optical microscope (OM), atomic force microscope (AFM) and Scanning electron microscopy (SEM) analysis showed that, increasing the surface roughness up to Ra = 0.16 micrometer, caused the greater degree of beam engagement by the surface grooves, hence more concentration of the beam photons and more melting obtained, so the depth of penetration increases by consuming a lower amount of energy.
N. Taheri Moghaddam, A. Rabiezadeh, A. Khosravifad, L. Ghalandari,
Volume 8, Issue 2 (1-2023)
Abstract
Despite the increased use of aluminium alloys in several industries, their common concern is the difficulty of joining dissimilar alloys using welding techniques. Based on this, the primary purpose of this research is to assess the mechanical characteristics of dissimilar joining of heat-treatable 6061 and non-heat-treatable 5083 aluminium alloys by gas tungsten arc welding and to discover the link between microstructure and mechanical properties. Similar welds were also implemented and evaluated in order to more properly analyze and compare the outcomes. The quality of the weld generated after establishing the health of the joint using non-destructive testing was evaluated by destructive bending, tensile, metallographic, and hardness tests to check the mechanical and microstructural qualities. The intended dissimilar weld was produced under the parameters of pulse current 120-80 amps, voltage 20 volts, welding speed 15 cm/min, and filler 5356. It should be highlighted that the dissimilar weld had the maximum joint efficiency, and with perfect control of welding settings and the absence of flaws, only 36% loss of strength was recorded when compared to the base metal. Metallographic images revealed that the formation of hot cracks in the dendritic structure of the weld metal is the major cause of strength loss for 5083 similar weld and the production of numerous porosities in the weld metal for 6061 similar welds.
M. Ahmadi, H.r. Ahmadi, M.r. Khanzadeh, H. Bakhtiari,
Volume 9, Issue 1 (5-2023)
Abstract
In this research, friction stir welding of aluminum 1050 to copper with variable speed was investigated. For friction stir welding, rotational speeds of 900 and 1200 rpm and traverse speeds of 36, 63, and 125 mm/min were used. In order to check the phases and microstructure, scanning electron microscope analysis, X-ray spectrometry, and hardness testing were used. The disturbance zone included Al2Cu3, Al4Cu9, AlCu4, Al2Cu, and AlCu phases. The results showed that the formation of intermetallic phases and severe plastic deformation in the welding area caused an increase in hardness. The highest hardness value in the stirred area was 97.8 Vickers at a rotation speed of 900 rpm and an advance speed of 36 mm/min.
A. Lalpour, M. Mosallaee, A. Ashrafi,
Volume 9, Issue 1 (5-2023)
Abstract
In the present study, friction stir processing (FSP) technique was carried out on the AA2024 sheet at different traverse speed (63 to 250 mm/min) and rotation speed (315 to 800 rpm). The temperature and grain size of stirred zone (SZ) were measured and their relationship was analyzed and effect of FSP parameters on the grain size of SZ was determined. Experiment and analytical investigations revealed that SZ grain size complies the exponential temperature-dependent relationship and can be defined the mathematical equation. Calculations indicate that a change in operational variables (rotation and traverse speeds) makes no variation in strain rate, and it is constant.
M. Naseri Alenjagh, T. Saeid,
Volume 9, Issue 1 (5-2023)
Abstract
The purpose of this research is to investigate the change of rotational speed and traverse speed on the microstructure and mechanical properties of the joint in friction stir welding of aluminum 1050 and 316L stainless steel. For this purpose, the microstructure, thickness of intermetallic compounds, hardness and tensile test on the joint were investigated. The proper selection of welding parameters leads to the creation of a joint with suitable metallurgical and mechanical properties. In this research, two rotational speeds of 560 and 900 rpm and four traverse speeds of 60, 80, 100 and 125 mm/min were performed. The microstructure consisted of four areas of the base metal, heat affected zone, thermo-mechanical affected zone and stir zone. In all the samples, the stir zone (SZ) contained a recrystallization microstructure with fine equiaxed grains. According to the Energy dispersive X-ray Spectroscopy results, an IMC layer formed in the joint interface. The hardness of the stir zone in all samples was higher than the aluminum base metal due to the formation of recrystallization fine equiaxed grains and the presence of steel particles. The best sample in terms of mechanical properties, mocrostructure and joint quality was obtained in the conditions of rotation speed of 900 rpm and advance speed of 125 mm/min. The strength was equal to 84 MPa with 77% efficiency.
A. Gandomdoust, M. Sarkari Khorrami, S. F. Kashani-Bozorg, H. Ghorbani,
Volume 9, Issue 1 (5-2023)
Abstract
As one of the important pillars of the fourth industrial revolution, metal additive manufacturing (AM) technologies provide a disruptive approach to digital manufacturing. Laser powder bed fusion (LPBF), as one of these technologies, has great potential in producing geometrically complex and high-performance parts. In recent years, the manufacturing of aluminum alloy parts using this technology has attracted much attention. However, their manufacturing still faces some challenging issues. One of the most serious issues encountered in the manufacturing of aluminum alloys, especially high-strength grades, is solidification cracking. In the present investigation, the formation mechanisms of solidification cracking, and the associated effective factors were reviewed. Controlling the solidification microstructure and grain refinement, using the addition of small quantities (<1 wt.%) of micro- or nano-sized particles to the initial alloying powder, was suggested as the most effective method for reducing solidification cracking. These particles act as nucleation sites, prevent grain growth, pin grain boundaries, and with the help of factors that provide constitutional supercooling can effectively minimize solidification cracking. Eventually, effects of various additives in grain refinement and their associated mechanism in reduction of solidification cracks of high-strength aluminum alloys by LPBF is presented.
Dr. Mojtaba Movahedi, Hosseinali Shirovi Khoozani, Ashkaan Ozlati,
Volume 9, Issue 2 (8-2024)
Abstract
Dr. Akbar Heidarzadeh, Mr. Rasoul Khajeh, Moosa Sajed,
Volume 9, Issue 2 (8-2024)
Abstract
In this research, the effect of nickel powder as an interlayer and the tool penetration depth on the microstructure and mechanical properties of lap joints between aluminum 1050 (top sheet) and pure copper (bottom sheet), both with a thickness of 2 mm, was investigated. Nickel powder was added through a machined groove with a width and depth of 1 mm at the base of the aluminum sheet. Friction stir lap welding was performed using a hot work steel tool with a shoulder diameter of 16 mm, a pin diameter of 4 mm, a pin height of 2.1 mm, a rotational speed of 950 rpm, a feed rate of 85 mm/min, a tool tilt angle of 2°, and varying tool penetration depths of 0, 0.05, and 0.1 mm. The results revealed that in the sample with a 0 mm penetration depth, due to insufficient heat generation, defects such as tunnel voids were formed. Increasing the penetration depth to 0.05 mm resulted in the formation of uniform and thin intermetallic layers, including Al3Ni2, Al7Cu4Ni, and Cu3.8Ni at the interface, which enhanced joint quality and increased tensile strength to 185.2 MPa with a fracture strain of 8.7%. In the sample with a 0.1 mm penetration depth, thicker and less uniform intermetallic layers were formed, which, despite locally increasing hardness, led to a decrease in tensile strength and fracture strain to 136.6 MPa and 6.7%, respectively. This study demonstrates that under the conditions of this research, a tool penetration depth of 0.05 mm provides the optimal conditions for FSLW of aluminum-copper alloys using nickel powder.
M.r. Hajiha, A. Farzadi, S. A. Samadani Agdam, A. Shabanzadeh, S. Ramezani,
Volume 9, Issue 2 (1-2024)
Abstract
5xxx and 6xxx series alloys are among the most widely used aluminum alloys in various industries, including automobile, shipbuilding and aviation industries. In this research, the joint of two alloys AA6061-T6 and AA5052-H12 was investigated at 4 transmission speeds of 60, 90, 120 and 180 mm/min and 3 rotation speeds of 600, 800 and 1000 rpm. These investigations were carried out in the condition that each of the two alloys was placed in two progressive and regressive sides. The results of these studies showed that the highest tensile strength is when the AA5052 sample is placed on the advancing side and the transfer speed is 90 mm/min and the rotation speed is 600 rpm, and in this case, the final tensile strength value is equal to 197 MPa. In addition, the results showed that, generally, the tensile strength decreases with an increase in the transmission speed at a constant rotational speed, and with an increase in the rotational speed at a constant transmission speed, the tensile strength increases. In addition, microscopic and macroscopic examination of the sections of all samples was performed and various areas and defects were examined. According to the investigations carried out on the microstructure, the grain size in the weld nugget compared to the base metal, HAZ and TMAZ decreases. The grain size in HAZ is the largest in all samples, and this causes a decrease in weld strength in this zone.
M.r Borhani, S.r. Shoja-Razavi, F. Kermani,
Volume 10, Issue 1 (6-2024)
Abstract
In this study, the effects of friction stir welding (FSW) parameters on the properties of dissimilar joints formed between 5083 aluminum alloys and 316L austenitic stainless steel, with a thickness of 4 mm, are investigated. The tool speed is varied in the range of 16 to 25 mm/min, while the tool rotation speed is maintained at a constant value of 250 rpm. To examine the microstructure of different weld regions, both optical and scanning electron microscopes are employed. To assess the mechanical properties, hardness and tensile tests are conducted. The results shows the formation of a composite region characterized by steel reinforcement particles dispersed within an aluminum matrix. At the steel-aluminum interface, a single layer of discontinuous intermetallic composition with a thickness of approximately 2 micrometers is observed. Notably, when the rotation speed is set to 250 rpm and the tool speed is 16 mm/min, a tensile strength of 298 MPa and ductility of 26% (93% of the tensile strength and 50% of the ductility of the 5083 aluminum alloy) are achieved.
