Aluminum Parts Research Articles

The Effect of Atomic Interdiffusion at the Al/Сu Interface in an Al/Сu Composite on Its Mechanical Properties: Molecular Dynamics

Composites with an aluminum matrix are relevant materials for research, since they are superior to conventional materials in their mechanical characteristics and can be used in various industries. In this work, the method of molecular dynamics is used to study the interdiffusion at an Al/Cu mixing interfaceunder compression combined with the shear deformation. Molecular dynamics tensile tests of the obtainedcomposite have been performed after combined compression to different strains. The deformation schemeused in this work is a simplified scenario that was previously experimentally performed to obtain Al/Cu composites.It has been shown that compression combined with the shear deformation is an effective way to obtaina composite structure. It has been found that under deformation Cu atoms more easily diffuse into an Al blockthan Al atoms diffuse into a Cu block. Tensile tests performed after the combined compression show that fracturingoccurs in the aluminum part of the composite; therefore, the Al/Cu mixing interface is stronger thanthe pure aluminum part.

Characterization of 5356 Aluminum Walls Produced by Wire Arc Additive Manufacturing (WAAM).

Wire arc additive manufacturing (WAAM) is renowned for its high deposition rate, enabling the production of large parts. However, the process has challenges such as porosity formation, residual stresses, and cracking when manufacturing aluminum parts. This study focuses on ana-lyzing the porosity of AA5356 walls manufactured using the WAAM process with the Fronius cold metal transfer system (Wels, Austria). The walls were machined to obtain specimens for tensile testing. The study used computed tomography and the tensile test to analyze the specimens' porosity and its potential relation to tensile strength. The process parameters analyzed were travel speed, cooling time, and path strategy. In conclusion, increasing travel speed and cooling time significantly affects pore diameter due to the lower heat input to the weld zone. Porosity can be reduced when diminishing heat accumulation. The results indicate that an increase in travel speed produces a slight decrease in porosity. Specifically, the total pore volume diminishes from 0.42 to 0.36 mm3 when increasing the travel speed from 700 to 950 mm/min. The ultimate tensile strength and maximum elongation of the 'back and forth' strategy are slightly higher than those of the 'go' strategy. After tensile testing, the ultimate tensile strength and yield strength did not show any relation to the porosity measured by computed tomography. The percentage of the pore total volume over the measured volume was lower than 0.12% for all the scanned specimens.

A Comparative Study on the Production of a Hat Profile by Roll Forming and Stamping

Lightweight design using high‐strength aluminum alloys has gained importance due to the continuing need for weight reduction and increasing crash safety requirements in the automotive industry. There are various manufacturing processes available for processing high‐strength aluminum alloys. Herein, the production of high‐strength aluminum parts by roll forming and stamping based on the example of an AA7075‐T6 hat profile is compared. Roll forming represents a continuous manufacturing process, while stamping is a discontinuous process. Different process routes (T6, W‐Temper and O) for roll forming as well as for stamping (T6, W‐Temper, O and hot forming) are in focus of the investigation. Fundamental differences of the forming processes and the tempering condition are observed and criteria for the choice of the manufacturing process and process route are presented. The temperature‐supported process routes improve the poor cold formability of AA7075 alloy and thus enhance the process window. Potential is offered for both manufacturing processes by applying tailored properties achieved through targeted quenching.

Verification of a Newly Developed Mobile Robot’s Actuator Parameters

This paper addresses the issue of the verification and comparison of the selected properties of a newly developed electric actuator. This actuator is intended to act as the drive of a walking robot designed for robotic football. Its envisioned placement is inside the robot’s knee joint and in its upper part. An integral part of the actuator is a harmonic precision gearbox and an absolute rotation sensor. The prototype of the newly developed actuator consists of both aluminum and 3D-printed parts. The selected parameters were verified according to the selected characteristics of ISO standard 9283, namely a one-directional pose accuracy and repeatable pose accuracy. The obtained data were compared with those of the standard actuator used thus far in constructing robots for robotic football. The implemented verification is based on the need to improve the performance parameters of the actuator while ensuring the sufficient accuracy of stopping the actuator in the required position. This is ensured by the use of a more accurate harmonic reducer and rotation sensor compared to the standard actuator.

Aluminum foams with complex pore topologies for acoustical applications

Metal foams are used in various industries due to the great variety of properties they possess such as high strength-to-weight ratio, high energy absorption, and the ability to endure extreme conditions. However, despite their desirable properties, traditional metal foams lack acoustic absorption properties because of their stochastic open porous structure—a function of the foaming process. Additive manufacturing (AM) can allow the fabrication of more complex foams; however, current metal AM methods provide significant processing and scalability challenges, especially in printing aluminum parts. Here, we present an alternative method for fabricating open-celled aluminum sound absorbers with controlled cellular architectures. The method relies on modeling the cellular templates using an implicit, field-based modeling method. The templates are then fabricated by combining polymer-based AM techniques and converted into aluminum Duocel® foams using ERG Aerospace Corporation’s proprietary foaming technology. The acoustical properties of the fabricated foams are then measured using a normal incidence impedance tube method. Our results show that this method allows the fabrication of highly complex cellular architectures that may be optimized to obtain application-specific multifunctional performance.

Development of Bi-hexagonal hybrid crash box subjected to axial loading for enhancement of crashworthiness

Crash box design had been developed to increase crashwortiness performance. The crash box cross section is one important parameter to increase the energy absorption as crashwortiness performance. In the previous study, hexagonal cross section provide the higher energy absorption than other cross section. One of strategy to increase cross section is using two cross section put together in one component of crash box design. Bi-tubular crash box shows higher energy absorption with easy manufacture opportunity. In other study, hybrid crash box is investigated to reduce crash box mass. In this study, development of bi-hexagonal hybrid crash box subjected to axial loading to enhance crashworthiness were investigated. Analysis of crash box design is developed by using computer simulation with ANSYS Workbench 19.2. The crash box materials used are Aluminum Alloy and carbon-epoxy woven. The material modeling in the crash box is assumed as deformable body while the impactor is a rigid body. The axial loading is modelled by setting impactor impact the crash box with a speed of 7.67 m/s. Fixed support is set on the bottom of crash box. Nine of frontal test models were simulated for the bi-hexagonal hybrid crash box with different layups orientation angle and composite hexagonal tube diameter. Energy absorption and deformation patterns were observed. The results indicated that the highest energy absorption and specific energy absorption is occured on the A60 model with layups orientation angle of [0/60/0/60] and composite hexagonal tube diameter of 41 mm are 3693.8 J and 19.121 kJ/kg. The deformation pattern in the aluminum part is diamond mode, while in the composite part, the deformation pattern produce transverse shearing, lamina bending, brittle fracturing and local buckling mode

Breaking the strength–ductility trade-off in additively manufactured aluminum alloys through grain structure control by duplex nucleation

Achieving a homogeneous equiaxed grain structure and breaking the strength–ductility trade-off in additively manufactured aluminum alloys is a great challenge. In this paper, we propose a novel duplex nucleation mechanism that combines ex situ TiB2 and in situ Al3Ti for controlling the grain structure of additively manufactured AlCuMgTi-TiB2 composites. We conducted thermodynamic calculations and phase-field simulations to elucidate the duplex nucleation-based grain structure control. The Al3Ti-coated TiB2 inoculant system formed via duplex nucleation during solidification enabled the formation of a homogeneous ultrafine equiaxed microstructure in both the as-fabricated and heat-treated states. Different from the AlCuMgTi alloy, the TiB2-reinforced AlCuMgTi composites produced via laser powder bed fusion were amenable to the simultaneous enhancement of strength and ductility. The proposed alloy design approach and duplex nucleation mechanism can guide the tailoring of the microstructure and mechanical properties of additively manufactured aluminum parts.

Micro-Arcs Oxidation Layer Formation on Aluminium and Coatings Tribological Properties—A Review

This review proposes to carry out a state-of-the-art associated with micro-arc oxidation. Firstly, the different aspects of the growth mechanisms of the oxides are detailed. Then, the formation of micro-arcs and the case of soft-spark treatment are discussed. Then, the electrolytic reactions involved in the layer construction are outlined. We focused on the influence of aluminium alloys on the appearance of the coating and its characteristics before considering the electrolyte formulation. We have concentrated some of our efforts on silicate-based electrolytes, mainly used in research and industry. The importance of electrical parameters in layer formation is detailed later. The main factors studied in the literature are the current source, current density, treatment frequency and duration, and duty cycle. We have also noted the different phase compositions identified in the literature. Finally, since the process is particularly advantageous for protecting the surfaces of aluminium parts against wear, we conclude this review by presenting work on the tribological properties of this coating. In this final section, we highlight the work on the wear-reducing properties and tribological mechanisms identified in the literature. Particular attention is paid to the relationship between the nature of the substrates used, the role of the electrolyte and the counterpart choice on the friction and wear results.

An Experimental and Numerical Study on Aluminum Alloy Tailor Heat Treated Blanks

Information is presented on the conceptualization, experimental study, and numerical process simulation of tailor heat treated aluminum alloy blanks. This concept is intended to improve the forming behavior of aluminum parts in challenging conditions. The implementation requires precise control of laser heat treatment parameters within a suitable industrial framework. The study details material properties, heat treatment parameters, and experimental results for the strength and elongation properties of an AA6063-T6 aluminum alloy. Constitutive modeling is applied using the Hocket–Sherby equation, which allowed us to establish a correlation between laser heat treatment maximum temperature and the corresponding material softening degree. Based on the generated flow stress–strain curves, a numerical simulation of a representative case study was performed with Abaqus finite element software highlighting potential improvements of tailor heat treated blanks (THTB). The influence and effectiveness of heat-affected zone (HAZ) dimensions and material softening were analyzed.

Initiation and Mechanisms of Plasticity in Bimetallic Al-Cu Composite

We studied the shear deformation of a laminar Al-Cu composite with (100) and (110) interfaces with a shear perpendicular to the lamellae in comparison with pure single crystal Al and Cu at strain rates of 109 s−1 and 108 s−1 and different initial pressures in the range from −3 GPa to +50 GPa. The results of molecular dynamics (MD) for the plasticity initiation are generalized by means of an artificial neural network (ANN) trained by MD data for the (100) interface, and a rate sensitivity parameter identified using MD data for different strain rates. The ANN-based approach allows us to extrapolate MD data to much lower strain rates, which are more relevant for typical dynamic loadings. The considered problem is of interest as an example of the application of the developed ANN-based approach to bimetallic systems, whereas previously it was tested only for pure metals; in addition, Al-Cu composites are of practical interest for technology. The interface between metals reduces the shear strength of the composite in comparison with both pure metals. At an initial pressure below 10 GPa, the plasticity begins in the aluminum part of the composite, while at higher pressures, the plasticity of the copper part starts first. At a pressure above 40 GPa, a phase transition in the aluminum part governs the plasticity development. All this leads to a nonmonotonic pressure dependence of the critical shear stress of the Al-Cu composite in the case of (100) and (110) interfaces without misorientation. Misorientation decreases the critical stress of the nucleation of lattice dislocation and makes the pressure dependence of this stress monotonic. Deformation modes, with a defect-free copper part and a strain-accommodating aluminum part are observed in the MD and can be useful for technological applications related to deformable conducting materials.

Examination of surface roughness values of 6061-T6 aluminum material after machining and after anodizing process

The use of aluminum material is very common, especially in parts that require precision mechanical processing, such as in the aerospace or defense industry. Since weight reduction in related vehicles or technologies in the fields of aviation and defense industry is one of the biggest goals, the use of aluminum as a metal material has become one of the first targets. The high weight/strength ratio of aluminum compared to steel is one of the main reasons why it is preferred. In addition to these advantages of aluminum materials, we have two expectations for 6061 aluminum parts in most of the projects we work on. The first is to minimize the frictional intensity of the aluminum parts working in contact with each other. The second is to provide the surface roughness of the gasket pressing surface on the surfaces where gaskets are used due to the need for sealing. For both requirements, our goal in this study will be to achieve the surface roughness value as maximum Ra 0.2 after machining and maximum Ra 0.3 after anodizing. The study was carried out with six different cutting tools. These tools, in order; end mill (with one insert) cutter, end mill (with two inserts) cutter, solid end mill, single insert diamond tool, monocrystalline diamond tool and superfinishing tool. Particular attention was paid to the cleanliness of the chemical baths used in the anodizing specific to this study. As a result, it has been observed that much more precise results can be achieved than the currently accepted surface roughness value when suitable machining parameters and optimum anodizing coating parameters are used. By using different cutting parameters with the same tool, by increasing the speed and feed values and decreasing the depth of cut, there is a slight improvement in the surface roughness values. The results of the experiments are presented in table and graphic and are suitable only for observed cutting conditions, used tools and material.

Mechanical Design and Fabrication of a Data Buoy

A data buoy for measuring coastal wave-action has been designed and constructed. The buoy is essentially a 0.6 m diameter sphere that is made of fiber-glass with aluminum, steel and polymer parts. While the overall geometry of the buoy is superficially similar to that of existing commercial spherical buoys (e.g. Wave-Rider by Datawell), the present design is based on a simple robust structure and mass-market electronics. A significant dual-use feature of this design is that the structure is usable as a float in a wave-energy generation device. This is possible due to the essentially isolated central structure and an electronics enclosure that is sealed both from the external environment and from the bulk shell of the buoy. This also allows the electronics to be mounted in an easily- modified, rack configuration that can be removed from the buoy shell. In a wave-energy generation set-up the electronics rack would be removed and the central cylinder will become part of a linear-motion type generator, with at least +/- 25 cm of internal movement available to it that is waterproof (for near surface or shallow immersions). Alternatively, for large wave motions, the buoy can couple to an energy-generating device using flanges that mate with its bolt circle pattern. However, at the moment, the buoy enclosure is dedicated to wave-action measurement, i.e., a data buoy with an onboard inertial measurement unit (IMU) and a radio-link to send real-time data to a receiving unit that can be on a boat or at the seashore. Basic GPS data are also transmitted. This is of interest if the buoy is being deployed in a drifting (un-moored) mode. This paper will only discuss the mechanical design and fabrication of the structure.

Формирование биметаллического материала Ti–Al методом проволочного электронно-лучевого аддитивного производства

Currently, there is a request from aerospace and aircraft for the construction materials with sufficiently high mechanical strength, thermal creep, corrosion and oxidation resistance. The conventional alloys used for these purposes are too heavy. At the same time, alternative light materials such as Ti–Al-based alloys have many flaws, when they are produced by conventional methods. This work considers the possibility to produce the Ti–Al-based alloys by the method of a wire-feed electron-beam additive manufacturing (EBAM). We study the chemical and phase compositions, microstructure and microhardness of a bimetallic Ti–Al alloy, obtained by this method. It is found the formation of five characteristic regions between titanium and aluminum parts of the bimetallic billet. The mixing zone consists of TiAl and TiAl3 intermetallics, that is confirmed by the investigation of microstructure, chemical and phase compositions. According to XRD (X-ray diffraction) and EDS (energy-dispersive X-ray spectroscopy) analyses, it can be assumed that TiAl intermetallic prevails over TiAl3 one. The average microhardness of the mixing zone equals to 450 HV (≈4.4 GPa). This zone has developed dendritic microstructure, and even distribution of the phases without link to dendritic and inter-dendritic zones. The cracks appearing in this area are filled with the material of the upper layers, so the whole material is poreless and defect-free. Thus, the results of this work have shown a fundamental possibility to produce the intermetallic Ti–Al alloys with the use of the EBAM.

AI-based Product Quality Controlling in an Anodizing Process

Product quality is a crucial factor of customer satisfaction and thus directly influences the competitiveness of a company. In manufacturing companies the quality of production processes obviously has significant impact on product quality. Therefore, establishing automated quality control offers considerable leverage for improving processes without necessarily increasing work efforts and costs. In this paper an artificial intelligence based pattern recognition method for increasing the output of an anodising process for aluminium parts is discussed. In the use case presented here, customers have high aesthetic requirements regarding the products which are used in an expensive market segment with only limited fault tolerance. Preparation of the product parts before going through the anodising process is a manual, tedious, and error-prone task that nevertheless requires highest precision. Small deviations can lead to quality problems causing rejections and enforcing repetitions in production. We discuss the application of visual image processing with an artificial intelligence algorithm integrated into the information system of the company to monitor the process and prevent human errors. Results show that our approach reaches high accuracy and can potentially improve delivery reliability with respect to time and quantity by reducing cost-intensive manufacturing errors.

Inline Quality Monitoring of Reverse Extruded Aluminum Parts with Cathodic Dip-Paint Coating (KTL).

Perfectly coated surfaces are an essential quality feature in the automotive and consumer goods industries. They are the result of an optimized, controlled coating process. Because entire assemblies could be rejected if Out-of-Specification (OOS) parts are installed, this has a severe economic impact. This paper presents a novel, line-integrated multi-camera system with intelligent algorithms for anomaly detection on small KTL-coated aluminum parts. The system also aims to automatize the previously used human inspection to a sophisticated and automated vision system that efficiently detects defects and anomalies on coated parts.

Prevention of local corrosion of aluminum alloy pontoons in steel tanks

Over the years of existence of the oil and gas industry, increasing the efficiency of equipment at production facilities places increasing demands on operational reliability and durability. The use of aluminum alloys is due to a large range of its features and properties, one of which is the combination of high strength in combination with low density, sufficient corrosion resistance, good moulding ability by casting, pressure and cutting, the possibility of using aluminum parts in all kinds of structures by welding, soldering and other methods. It is important to bear in mind that aluminium alloys do not require regular corrosion coating during operation. It is all about the finest and extremely strong oxide film (0.00001 mm), which forms a reliable adhesion to the metal.

Cooling rate as a process parameter in advanced roll forming to tailor microstructure, mechanical and corrosion properties of EN AW 7075 tubes

AbstractThe effects of solution heat treatment parameters and quench media as a processing tool for tailoring microstructure, mechanical and corrosion properties in roll forming of EN AW 7075 alloy were studied. The highest yield stress and ultimate tensile strength were obtained for the specimens quenched in water, while the air‐cooled specimens exhibited inferior mechanical properties. Microstructural analysis of specimens showed that except water‐quenched specimens, the parts cooled/quenched in oil, in direct contact with tool steel and air are characterized by coarse precipitates and precipitate‐free zones. The corrosion tests showed that the cooling rate has a pronounced influence on the corrosion resistance and related mechanism of EN AW 7075 alloy. The surfaces of specimens quenched in water remained intact although pitting corrosion took place. The microstructure of the part processed by roll forming was explored in direct comparison. It is revealed that by the employment of quenching nozzles, a high cooling rate similar to the water‐quenched condition can be achieved. Results obtained in the present study pave the way to directly tailor aluminum parts for specific applications.

Deep learning-based detection of aluminum casting defects and their types

Due to its unique properties, high-pressure aluminum die-casting parts are used quite often, especially in the automotive industry. However, die-casting is a process which requires non-destructive testing of the critical components using technologies such as X-ray to examine the internal defects that are not otherwise visible. Such a timeconsuming visual inspection requires well-trained human specialists with the utmost attention. In this study, state-of-the-art deep learning-based object detection methods were trained using an X-ray image dataset of aluminum parts to detect internal defects and predict their types without human attention. The Al-Cast image dataset used in this study contains 3466 images of parts produced in high-pressure die casting machines. It is shared as an open-access original database for the nondestructive testing (NDT) community. ASTM standard definitions for aluminum casting defects are used in determining their types, and to the best of our knowledge, this novel approach is the first in the deep learning literature. Among the 12 deep learning-based object detection methods used for comparison, YOLOv5 versions yielded the highest detection accuracy (0.956 mAP) with the shortest training time (0.75 h). In addition, tests were performed for both original and contrast enhanced images on 348 test images. YOLOv5m performed an accurate detection performance of 95.9%. Additionally, YOLOv5n can process 132 images per second. This study can be considered the first step of an artificial intelligence product that can detect internal defects of aluminum casting parts with industrial standards and explain the relationship between highpressure injection die casting parameters and these defects.

Tailoring of Dissimilar Friction Stir Lap Welding of Aluminum and Titanium

An approach was proposed to optimize dissimilar friction stir lap welding of aluminum and titanium alloys. The basic concept of the new technique included (i) the plunging of the welding tool solely into the aluminum part (i.e., no direct contact with the titanium side) and (ii) the welding at a relatively high-heat input condition. It was shown that sound welds could be readily produced using an ordinary cost-effective tool, with no tool abrasion and no dispersion of harmful titanium fragments within the aluminum side. Moreover, the intermetallic layer was found to be as narrow as ~0.1 µm, thus giving rise to excellent bond strength between aluminum and titanium. On the other hand, several important shortcomings were also revealed. First of all, the high-heat input condition provided significant microstructural changes in the aluminum part, thereby resulting in essential material softening. Furthermore, the new approach was not feasible in the case of highly alloyed aluminum alloys due to the relatively low rate of self-diffusion in these materials. An essential issue was also a comparatively narrow processing window.

Environmental impact of cold sprayed 3D-Printed aluminium metal parts

Cold spray additive manufacturing (CSAM) is a solid-state deposition process that is advantageous in depositing metal powders of heat- and oxygen-sensitive materials such as aluminium. CSAM is being considered for many applications. However, the environmental impact of CSAM of metal parts production are not well known. Therefore, the environmental impact of CSAM, in which energy consumption and CO2 emission are used as indicators in the life cycle assessment are considered in this study. We have calculated the specific energy consumption of CSAM at increasing process rate of 0.273 kg/h, 0.550 kg/h and 0.753 kg/h to be 373.0 MJ/kg, 225.1 MJ/kg, and 178.7 MJ/kg, respectively. The production of aluminium parts of different shapes was used for the cradle-to-grave life cycle analysis of machining and CSAM at different process rates. We have found that increasing process rates in CSAM of aluminium production as the route that allows less energy consumption and carbon dioxide emission compared to reducing the material used. This provides a route for optimising the layer thickness by increasing the process rate and lowering the environmental impact by reducing the number of layers required to build the parts in additive manufacturing.