Form Of Billets Research Articles

Optimizing strength of directly recycled aluminum chip-based parts through a hybrid RSM-GA-ANN approach in sustainable hot forging.

Direct recycling of aluminum waste is crucial in sustainable manufacturing to mitigate environmental impact and conserve resources. This work was carried out to study the application of hot press forging (HPF) in recycling AA6061 aluminum chip waste, aiming to optimize operating factors using Response Surface Methodology (RSM), Artificial Neural Network (ANN) and Genetic algorithm (GA) strategy to maximize the strength of recycled parts. The experimental runs were designed using Full factorial and RSM via Minitab 21 software. RSM-ANN models were employed to examine the effect of factors and their interactions on response and to predict output, while GA-RSM and GA-ANN were used for optimization. The chips of different morphology were cold compressed into billet form and then hot forged. The effect of varying forging temperature (Tp, 450-550°C), holding time (HT, 60-120 minutes), and chip surface area to volume ratio (AS:V, 15.4-52.6 mm2/mm3) on ultimate tensile strength (UTS) was examined. Maximum UTS (237.4 MPa) was achieved at 550°C, 120 minutes and 15.4 mm2/mm3 of chip's AS: V. The Tp had the largest contributing effect ratio on the UTS, followed by HT and AS:V according to ANOVA analysis. The proposed optimization process suggested 550°C, 60 minutes, and 15.4 mm2 as the optimal condition yielding the maximum UTS. The developed models' evaluation results showed that ANN (with MSE = 1.48%) outperformed RSM model. Overall, the study promotes sustainable production by demonstrating the potential of integrating RSM and ML to optimize complex manufacturing processes and improve product quality.

Comparison of Linear and Nonlinear Twist Extrusion Processes with Crystal Plasticity Finite Element Analysis.

The mechanical characteristics of polycrystalline metallic materials are influenced significantly by various microstructural parameters, one of which is the grain size. Specifically, the strength and the toughness of polycrystalline metals exhibit enhancement as the grain size is reduced. Applying severe plastic deformations (SPDs) has a noticeable result in obtaining metallic materials with ultrafine-grained (UFG) microstructure. SPD, executed through conventional shaping methods like extrusion, plays a pivotal role in the evolution of the texture, which is closely related to the plastic behavior and ductility. A number of SPD processes have been developed to generate ultrafine-grained materials, each having a different shear deformation mechanism. Among these methods, linear twist extrusion (LTE) presents a non-uniform and non-monotonic form of severe plastic deformation, leading to significant shifts in the microstructure. Prior research demonstrates the capability of the LTE process to yield consistent, weak textures in pre-textured copper. However, limitations in production efficiency and the uneven distribution of grain refinement have curbed the widespread use of LTE in industrial settings. This has facilitated the development of an improved novel method, that surpasses the traditional approach, known as the nonlinear twist extrusion procedure (NLTE). The NLTE method innovatively adjusts the channel design of the mold within the twist section to mitigate strain reversal and the rotational movement of the workpiece, both of which have been identified as shortcomings of twist extrusion. Accurate anticipation of texture changes in SPD processes is essential for mold design and process parameter optimization. The performance of the proposed extrusion technique should still be studied. In this context, here, a single crystal (SC) of copper in billet form, passing through both LTE and NLTE, is analyzed, employing a rate-dependent crystal plasticity finite element (CPFE) framework. CPFE simulations were performed for both LTE and NLTE of SC copper specimens having <100> or <111> directions parallel to the extrusion direction initially. The texture evolution as well as the cross-sectional distribution of the stress and strain is studied in detail, and the performance of both processes is compared.

Effect of chemical composition and heat treatment on intergranular corrosion and strength of AlMgSiCu alloys

Abstract The use of aluminum in chassis, bumper, and crash boxes has increased in the last 10 years with an increase in the production of electric vehicles in the automotive industry. The extrusion process has also gained importance because it allows mass production. While basic 6xxx series aluminum alloys such as 6060 and 6063 were used in the early stages of the process, later on, 6005A and 6082 alloys, which provide higher strength, have been used. Alloys with higher strength and crash ability are needed with an increase in safety requirements in automotive. In this study, the effect of chemical composition and heat treatment on the intergranular corrosion strength of 6056 alloys was examined. Another aim of this study is not only to produce high strength and ductility alloy but also to provide good corrosion resistance as automotives are used in different environments for several decades. The 6056 alloys are potential candidate materials for the new-generation electrical vehicles in the automobile industry due to their high strength, weldability, machinability, and impact resistance. Therefore, in our work, we produced 6056 alloy samples in a billet form using the direct chill casting method. Then they were homogenized, and billets were extruded as a box profile. Experimental studies were carried out on 6056 alloys with two different chemical compositions and three different heat treatment conditions (T42, T62, and T76) using Method B of EN ISO 11846 standard for corrosion testing. Crack sizes of metallographic sections from corroded areas were calculated g using a scanning electron microscope. As a result, we found that the addition of Mg to 6056 alloys improves corrosion resistance, while copper reduces it. When Zn is added to the alloys, Mg starts to react with it and forms MgZn2, which increases the corrosion progress. Moreover, when heat treatment is applied at T76 conditions, the alloys demonstrate high corrosion resistance.

A Simulative Method for Studying the Bonding Condition of Friction Stir Extrusion

In the manufacturing industry, the problem related to the management of metal waste is of considerable importance, since it is produced in large quantities during mechanical processing.However, its recovery is not always a simple task, especially with regard to the metal cutting processes. In fact, due to the presence of surface oxide and contaminating oily residues, the recovery process of these components is often very expensive and polluting. This problem can be solved with the FSE process, patented in 1993 by The Welding Institute. The FSE can be counted among the main innovative processing techniques developed in Industry 4.0, as it involves only metal scraps coming from the machining processes as starting material, without providing for their preliminary re-melting in a billet form, and it uses only the heat generated by the friction between the tool and the metal. Since FSE is a quite recent process, the development of simulative models is useful for understanding its basic mechanisms. The objective of this research is to analyze if and how the bonding phenomena occour considering both the thermal and the stress conditions involved and generated by the process parameters.As a result, FEM analysis proved to be a valid tool to correctly forecast if bonding phenomena really take place and how process parameters affect the bonding quality. Moreover, it was possible to confirm that the Piwnik and Plata bonding model is a good criterion for predicting the effects of this technology.

Mathematical model of steel consumption minimization considering the two-stage billets cutting

Purpose. To achieve a decrease in energy and resource costs in the multi-stage production of rolled products within a given plan through the development of appropriate mathware. Methodology. The multi-stage problem mathware for producing rolling steel products is developed on the basis of system approach applying fundamental principles of the optimization and operation research theory. Realization of the developed mathematical model allows discovering such a strategy of using steel during the whole manufacturing process, which minimizes not only the steel waste at the moment of its casting in a mold, but also the offcuts in the process of cutting the obtained ingots into the billets. Findings. A mathematical task model is built to minimize the amount of steel for producing a certain order of size of one cast volume only. The developed model specifies the possibility to pre-evaluate the billet optimal size, based on the necessary cutting along the final product length, appropriate for the certain billet form of section, and ingot weight limits. Originality. A mathematical model is provided for the optimal metal distribution process when implementing the plan of manufacturing rolling products. The model, in contrast to the existing ones, shifts the emphasis on forming the optimal ingot weight, which has a pre-calculated optimal cutting plan. Practical value. The use of the developed mathematical optimization model (minimizing the amount of steel for producing a certain order) as part of an automated decision support system for management of rolling production will reduce the number of cutting machine changeover and minimize resources use and stock balance.

Digitalization to drive quality: the synergy between ladle tracking system and prediction models

ABSTRACT Tata Steel caters to the needs of its customers in two segments – long products and flat products. In the long products division, LD1 is the plant that manufactures steel and semi-finished products in the form of billets. At LD1, the Quality rejections are mainly due to the off chemistry in heats, which happens when different elements such as carbon, manganese, and silicon go beyond the specified chemitry range of the steel grade. A detailed analysis of the previously downgraded heats revealed that the major reason for the deviation was the erratic recovery of ferro alloys (FAs) added at the ladle furnace stage which in turn was due to the high variations in the steel weight in every ladle. Due to the variations in the tonnage of steel weight tapped and the actual heat weight, which were a crucial input to an exisitng static FA model, model the predictions of this model were inaccurate. In order to improve the accuracy of the prediction model, an Internet of things based ladle tracking system was implemented. This RFID-based system combined with the in-house developed real-time prediction model, for hot metal (liquid iron) + scrap to be charged in converters, resulted in improving the accuracy of steel weight being tapped and hence improving the FA predictions which eventually resulted in achieving the lowest ever quality rejections at LD Shop#1 in FY18. There have been multi-fold savings as a result of this: not only the loss due to rejections of heat was minimized but also the FA consumptions were reduced and due to tapping weight optimization, so there was improvement in the overall heat weight.

Characterization of Thin Laminates Present Inside the Aluminum Extruded Tubes

The commercial AA6061–T6 alloy was prepared from different grades of raw materials and casted in the form of billets. The 50-mm-thick tubes were extruded from this alloy, and the product quality was monitored through ultrasonic testing. The presence of internal defects within the bulk of material, their location, and size was also determined by 6 decibel drop method. To investigate the possible reasons for the inferior product quality and large rejection rate, the tubes manufactured from three different cast billets were produced and tested. The cross section of the polished specimens from the defect sites revealed the formation of oxide film laminates. The scanning electron microscope images showed the existence of entrapped hard phases which were aligned in the extrusion direction and formed internal fine cracks or fissures during extrusion process. The EDX, XRD, and XPS analyses of these oxide films also confirmed the presence of γ-Al2O3 and MgO along with some minor impurity elements (Fe, Si, Ca, Co, and Na).

Mechanical Properties of Solid-State Recycled 4xxx Aluminum Alloy Chips

The direct production of aluminum from bauxite ores is known to be a very energetic-intensive operation compared to other metallurgical processes. Due to energy issues and the rapid increase in aluminum demand, new kinds of aluminum production processes are required. Aluminum waste recycling, which has an advantage of lowering the cost of electric power consumption, is considered to be an alternative route for material manufacturing. In this work, the way of reusing aluminum EN-AC 44000 alloy scraps by hot extrusion was presented. Metal chips of different sizes and morphology were cold compacted into billet form and then hot extruded. Mechanical properties investigations combined with microstructure observations were performed. Mechanical anisotropy behavior of material was evaluated on the base of tensile test experiments performed on samples machined at 0°, 45°, and 90°, respectively, to the extrusion direction. It was found that the initial size of the chips has an influence on the mechanical properties of the received profiles. Samples produced from fine chips revealed higher tensile strength in comparison to larger chips, which can be attributed to a refined microstructure containing fine, hard Si particles and Fe-rich intermetallic phases. Finally, it was found that anisotropic behavior of chip-based profiles is similar to conventionally cast and extruded materials which prove good bonding quality between chips.

Development of low‐melting‐point filler materials for laser beam brazing of aluminum alloys

In order to develop low‐melting‐point filler materials for laser beam brazing of aluminum alloys, Al–Si–Cu based alloys and Al–Si–Zn based alloys were produced via spray forming and associated deformation processes. The selected alloys were spray formed in the form of billet with a diameter around 160 mm and hot extruded into wire rods with a diameter of 8 mm. The extrusions were further cold worked into thin wires with a diameter of 1.2 mm via rotary swaging. Finally, the filler wires were applied in the laser beam brazing of AA6082 structures. It showed that the newly developed filler materials could meet the requirements of the laser beam brazing of aluminum alloys. Particularly, the laser beam brazing process using the spray‐formed filler materials required a significantly lower energy input and allowed for higher brazing speed as compared to the conventional AlSi12 filler material.

Improving the Productivity of the Single Basin Solar still

A single basin single slope solar still with 0.82mx 0.81m x 0.75m has been fabricated with G.I sheet and tested with different water depths of 2,3,4cm. Various solid and liquid sensible heat storage materials, Evaporative surface materials are used in the form of billets, in the still. To reduce glass cover temperature the outer glass was cooled by using sprinkler manually at regular interval of time. Theoretical analysis was performed and compared with experimental values. The performances of modified still were compared with conventional still of same size running under the same meteorological conditions. The solid sensible heat storage materials produces48% more productivity than conventional still. Liquid sensible heat storage material produces 19% more than conventional in till. The payback period of the still was 340 days.

Formation of Structure and Properties in Casting Processes on the Example of AZ91 Magnesium Alloy

Abstract Contemporary materials engineering requires the use of materials characterised by high mechanical properties, as these precisely properties determine the choice of material for parts of machinery and equipment. Owing to these properties it is possible to reduce the weight and, consequently, the consumption of both material and energy. Trying to meet these expectations, the designers are increasingly looking for solutions in the application of magnesium alloys as materials offering a very beneficial strength-to-weight ratio. However, besides alloying elements, the properties are to a great extent shaped by the solidification conditions and related structure. The process of structure formation depends on the choice of casting method forced by the specific properties of casting or by the specific intended use of final product. The article presents a comparison of AZ91 magnesium alloys processed by different casting technologies. A short characteristic was offered for materials processed by the traditional semi-continuous casting process, which uses the solidification rates comprised in a range of 5 - 20°C/s, and for materials made in the process of Rapid Solidification, where the solidification rate can reach 106 °C/s. As a result of the casting process, a feedstock in the form of billets and thin strips was obtained and was subjected next to the process of plastic forming. The article presents the results of structural analysis of the final product. The mechanical properties of the ø7 mm extruded rods were also evaluated and compared.

Equal-channel angular extrusion of polymers

One of the priority lines of development of physics of polymers and material science is the development of the principles of structure modification of polymeric materials and the study of the relation between the structure and the properties, aimed to their control. Nowadays, great attention is paid to investigation of severe plastic deformation (SPD) effect on the structure modification of polymers and polymeric composites as well as to the development of the simple shear based methods of formation of orientation order. The main difference between SPD and traditional methods of pressure shaping such as die extrusion, rolling, drawing is the ability to accumulate essential plastic deformation in the processed materials. At the same time, the billet form and size are maintained and there is a possibility of development of varied deformation routes in order to generate different forms of molecular orientation. The most widely used SPD methods applied to polymeric materials are equal-channel angular extrusion (ECAE) and its modified version, so-called equal-channel multiple angular extrusion (ECMAE). The investigations carried out in research centers of USA, Japan, China, France and Ukraine showed perspectives of the use of these methods for improvement of the set of the existing physical and mechanical properties and the formation of functional properties previously unknown. In particular, in the case of semi-crystalline polymers, SPD results in increase in rigidity and strength at conserved high level of plasticity. For polymeric composites, SPD facilitates homogeneous distribution and better dispersion of the filler particles within the polymeric matrix, orientation of transition layers and polymeric matrix etc. As a result, physical and mechanical characteristics higher of those of polymeric composites without SPD were achieved.

Study of the Elasticity Module through Indentation Instrumented Technical of AlCuFeB Quasicrystalline Alloy

Quasicrystalline materials have unique properties such as high hardness, excellent surface properties, good resistance to oxidation and corrosion and low electrical and thermal conductivities. These materials can be obtained by conventional methods of metallurgy. However, quasicrystals are quite weak and this characteristic complicates their use in the form of billets for the manufacture of mechanical components. For this reason, the evaluation of mechanical properties of quasicrystalline materials using conventional methods, such as tension, compression, fatigue, among others, is not feasible. One method to evaluate the mechanical properties of quasicrystals is through instrumented indentation, once it is a very efficient tool for the calculation of properties such as hardness, fracture toughness and modulus of elasticity. The latter was the property studied in this work and that it is an important design criterion for the manufacturing of quasicrystalline alloys for their use in industry.

The Electrolytic Production of Ti from a TiO&lt;sub&gt;2&lt;/sub&gt; Feed (The DARPA Sponsored Program)

DARPA instituted an Initiative in Titanium in 2003 to produce titanium, alternatively to the Kroll process, in a billet form for under $4/lb. This DARPA sponsored program has gone into Phase II consisting of utilizing ore/TiO2 as a feed. The TiO2 is carbothermically reduced to a suboxide-carbide (Ti:O:C) which is used anodically to resupply the titanium content in an electrolysis process that deposits titanium in a powder morphology. The deposited powder is uniquely stripped from the cathodes and harvested in a separate stream that permits continuous electrolytic processing to produce titanium at an estimated cost about ½ the Kroll process. Oxygen contents less than 500 ppm are achievable with particle sizes in the desired range for powder metallurgy applications. The process has been demonstrated on a continuous basis and is in the stage of scaling-up to 500 lbs/day.