Drawing Operation Research Articles

The Application of Digital Technology in Public Building-The Han Hall Project at the Wuhan International Expo Center

This article takes the Han Hall project at the Wuhan International Expo Center as a case study to illustrate how digital technology has been applied in various stages of the construction process, including conceptual design, construction drawing design, engineering construction, and operation and maintenance management. It demonstrates the role of digital technology in the construction of public buildings.

Top coal drawing law for an extra thick coal seam under the single round group drawing method

To solve the problems of poor top coal drawing, lagging collapse, and difficulty in parallel operation of mining and drawing in extra-thick coal seams, considering the 8222 working face of the Tashan Mine as the engineering background, we first investigate the basic problems of fully mechanized top coal drawing mining in extra-thick coal seams using the single-round group drawing method (GDM). We then analyze the drawing law of top coal with different thicknesses under the single-round GDM from the aspects of top coal recovery (TCR) and drawing efficiency, coal loss mechanism, and the relation between TCR and gangue content (GC), providing a basis for determining the process parameters of GDM. Results indicate that as the top coal thickness increases, the number of drawing openings considerably influences drawing efficiency and top coal loss. And there is a notable thickness effect of the number of drawing openings on the top coal loss. There is a quantitative relationship among TCR, cumulative GC (CGC) and instantaneous GC (IGC), and CGC and TCR can be predicted based on the IGC. Consequently, theoretical analysis and numerical simulation results indicate that the optimal IGC threshold at the coal drawing openings between 31.2 and 40%. Through optimizing the coal drawing method and strictly controlling the IGC at the coal drawing openings on-site, the measured working face TCR increased from 75.25 to 90.12%, and CGC was controlled at approximately 9%. Meanwhile, the average coordination efficiency of mining and drawing time reaches 68.2%, effectively ensuring the construction of a coal mine with an annual output of 15 million tons.

A Practical Analysis of Wire Drawing Operation Effects on the Die and Product Behaviors

This study analyse the effects of different wire drawing experimental tests on the die and product properties. Drawing load, temperature, and wear rate are main die factors, that concerned with the interaction effects of drawing speed variation, wire angle alignment and lubrication. For the product, two factors; tensile strength and hardness are taken. A copper wire is drawing from (4.3 mm) into (3.5 mm) diameter with an area reduction of 1.65, 34% ratio.Six dies were employed in various alignments at three different angles (0°, 1°, and 2°), each has two different drawing speeds of (20 mm/min and 40 mm/min). Results show, the highest drawing load and temperature values in die no.5. The effect of using grease on the die wear rate found that the die wear decreases compared to without. But, when using mixed gradients under the same working conditions, the wear rate changed into coating layer on the die surface. The interaction effect of wire alignment on the product strength showing very small when dealing with low or higher speed, but elongation and ductility are significantly reduced with increasing the angle. The wire produced from die no.1, gives the highest micro hardness.

Experimental and Numerical Stress-Strain Analyses of Conventional and Intricate Shapes of LCS (1008-AISI) Sheet Metal Under Deep Drawing Operation

Experimental and Numerical Stress-Strain Analyses of Conventional and Intricate Shapes of LCS (1008-AISI) Sheet Metal Under Deep Drawing Operation

Sustainable tool technology: Wood-based forming tools for deep drawing of sheet metal

In order to improve adaptability to evolving manufacturing processes in an era marked by mass customization and individualization, while also meeting geopolitical climate objectives, it is necessary to employ more sustainable methods in sheet metal forming to enhance flexibility. Metal based rigid tooling systems require a lot of material and energy resources, when aiming for high flexibility and scalability with respect to small batch size production. To reduce the overall resource consumption and to meet climate restrictions, non-metallic tooling approaches can counteract these issues when aiming for individualization in sheet metal forming. Compared to conventional metal-based tooling approaches, wood-based forming tools may enable a potential resource reduction (e.g., carbon footprint) and offer an alternative tooling approach for sheet metal forming. Although the mechanical performance of wood is lower compared to conventional tooling steel, certain wood-based forming tools can potentially be implemented for sheet metal forming. In this work a feasibility study of wood-based tooling materials is executed to investigate the mechanical performance on drawn sheet metal parts in a deep drawing operation. Different composite structures are investigated for wooden forming tools of black locust (robinia pseudoacacia).

Influence of boriding on the tribological behavior of AISI D2 tool steel for dry deep drawing of stainless steel and aluminum

Deep drawing of stainless steel and aluminum is a widely adopted method for manufacturing various industrial goods. However, the wear damage produced to die tools is a recurring problem in these processes. While lubricants are often employed to lubricate and reduce die wear, dry deep drawing is the current best alternative for meeting green manufacturing demands. Hence, enhanced solid lubricants or surface treatments for dies are highly required. This study aims to evaluate and compare the tribological behavior of a heat-treated AISI D2 steel and a boriding AISI D2 tool steel against stainless steel (AISI 304) and aluminum alloy (AA 6061 T6) in the absence of lubricant. The boride coating was formed on the AISI D2 steel by the closed-pack boriding technique, resulting in a tooth-saw morphology with an overall thickness of 33.6 μm. X-ray diffraction analysis confirmed the presence of FeB, Fe2B, and Cr2B3 phases on the surface of the borided AISI D2 tool steel. Notably, the boriding treatment led to a significant increase in the surface hardness of the tool steel, reaching a value of 20.7 GPa. The coefficient of friction (CoF) behavior and wear were evaluated by pin-on-disk tests, simulating conditions similar to those found in cold deep drawing operations. The wear surfaces were analyzed by optical profilometry and scanning electron microscopy (SEM). The results suggest boriding as a suitable treatment to reduce wear damage on the surface of deep drawing dies used for stainless steel and aluminum forming processes in the absence of lubricant. Two-body abrasion and adhesion were identified as the main wear mechanisms in AISI D2 steel against stainless steel and aluminum, with a significant amount of oxidation observed when aluminum was tested. Additionally, a reduction of approximately 20 % in the CoF was observed when employing borided tool steel against stainless steel. However, there was an observed increase of around 75 % in the CoF when the borided tool steel was tested against aluminum.

Numerical investigation of an extra-deep drawing process with industrial parameters: formability analysis and process optimization

Extra-deep drawing is one of the most important sheet metal forming processes. The appearance of rupture and wrinkling are the most commonly encountered problems in this process. These defects are also very common at a local company, particularly in the manufacturing of wheelbarrow trays. As a consequence, substantial time and costs are incurred in industrial production. To thoroughly analyze and address these defects, the extra-deep drawing operation of the wheelbarrow tray was modeled by the FE method using Abaqus software. A defect-free manufactured wheelbarrow tray was used to validate the accuracy of the numerical approach. Precise measurements of its dimensions were taken through the reverse engineering process using a 3D scanner. Furthermore, other measurements were made with an ultrasonic thickness gauge to have more precise measurements of the product’s thickness. Comparing experimental and numerical results showed good agreement. The outcomes of the numerical analysis indicate that the final shape of the wheelbarrow tray does not contain rupture or wrinkling defects, accurately corresponding to the real cases manufactured at the company. Numerical modeling and optimization of the extra-deep drawing process performed in this study could potentially reduce production losses and improve the overall efficiency of industrial manufacturing.

Analysis of Coefficient of Friction of Deep-Drawing-Quality Steel Sheets Using Multi-Layer Neural Networks

This article presents the results of an analysis of the influence of friction process parameters on the coefficient of friction of steel sheets 1.0347 (DC03), 1.0338 (DC04) and 1.0312 (DC05). A special tribometer was designed and manufactured in order to simulate the friction phenomenon occurring in the blankholder area in deep drawing operations. Lubricant was supplied to the contact zone under pressure. The value of the coefficient of friction was determined under various contact pressures and lubrication conditions. Multi-layer artificial neural networks (ANNs) were used to predict the value of the coefficient of friction. The input parameters considered were the kinematic viscosity of lubricants, contact pressure, lubricant pressure, selected mechanical properties and basic surface roughness parameters of sheet metals. The value of the coefficient of friction of 1.0312 steel sheets was predicted based on the results of friction tests on 1.0347 and 1.0338 steel sheets. Many ANN models were built to find a neural network that will provide the best prediction performance. It was found that to ensure a high performance of ANN prediction, it is necessary to simultaneously take into account all the considered roughness parameters (Sa, Ssk and Sku). The predictive performance of the ‘best’ network was greater than R2 = 0.98. The lubricant pressure had the greatest impact on the coefficient of friction. Increasing the value of this parameter reduces the value of the coefficient of friction. However, the greater the contact pressure, the smaller the beneficial effect of pressure-assisted lubrication. The third parameter of the friction process, the kinematic viscosity of the oil, exhibited the smallest impact on the coefficient of friction.

BLANK MATERIAL INFLUENCE ON STAMPING SPRINGBACK

This paper concerns the evaluation of blank material influence on springback of irregularly shaped stamping after drawing operation to keep the dimensions and tolerances of stamping after the drawing process which are given in part drawing. Simulation of the drawing process and consequent stamping springback were carried out by PAM-STAMP 2GTM software which uses the finite elements method, with the use of blanks from strip steels DX54D, HC220P, HX220BD and HX220YD. Two mesh strategies for drawing tool parts in the software PAM-STAMP 2GTM were compared. Stamping springback was evaluated with the use of a reference points system. Critical areas of deformations and stamping springback were evaluated. Simulation results were compared with measurements on real stampings. The most suitable strip steel in terms of achieving the minimum size of springback after stamping drawing was evaluated.

Experimental investigation and numerical optimization of sheet metal forming limits during deep drawing process of DD14 steel

This work aims to experimentally study the deep drawability of DD14 hot-rolled steel sheets and to optimize numerically the material formability. The material anisotropy was confirmed by metallographic analysis of the material and tensile tests on specimens taken in three orientations with respect to the sheet rolling direction. Where the stress-strain curves show a sensitivity of material to the Piobert-Lüders phenomenon. The die pressure and the blank holder were considered as controlling factors on plastic instability and the success of the deep drawing operation. The forming limit curves (FLC) were plotted to highlight the different deformation modes that the sheet metal underwent during the deep drawing process. The collected deep-drawn parts observation shows severe plastic instability, until fracture. The initial plastic anisotropy is determined by the Hill48 quadratic criterion and the work hardening by the Hollomon power law. It results, during the experimental tests, that the front bottom corners of the deep drawn part are the areas at high risk of damage. The various numerical simulation scenarios followed by comparisons with the experimental results, allowed us to confirm the optimum conditions that minimize the material's plastic instability risks, forming operation “Step” and BHP “Amplitude”.

Effect of silver and heat treatment on properties of 03Kh17N10M2 austenitic steel wire

The article examines the influence of various heat treatments, their temperature, as well as silver alloying on mechanical properties, phase composition and structure of steel wire from chromium-nickel-molybdenum austenitic stainless steel 03Kh17N10M2. Choice of the amount of silver alloying was based on previous studies of the antibacterial effect of modifying medical steels with silver. Since the antibacterial effect was confirmed on several bacterial strains, for the most efficient operation of alloys, it is necessary to determine the best temperature mode for working with them. Steel for the study was smelted and then transformed into wire through rolling, forging and drawing operations. On the obtained wire samples of different diameters with a silver content (0; 0.2 and 0.5 wt. %) mechanical tests were carried out to determine the elongation, yield strength and tensile strength. Various modes and temperatures of heat treatment were tested on wire of different diameters to study their effect on mechanical properties and structure. Microstructure of the wire samples subjected to heat treatment and obtained after drawing was investigated. A phase analysis was also carried out to determine the effect of silver in various quantities on austenitic steel. According to the results of the phase composition analysis, it was concluded that silver reduces the amount of gamma phase in steel, and this effect increases in proportion to the increase in silver amount. This change correlates with a slight drop in the metal ductility. At the same time, there are no significant changes in the strength characteristics and microstructure from the presence of silver.

Investigation on a novel in-line incremental die forming process for sheet metals

In this study, an alternative to the conventional cold-roll-forming process was developed. The new in-line incremental die forming process is a continuous manufacturing process that can provide rapid prototyping of automotive components. This new process combines the pressing and drawing operations. The feasibility of using ultra-high-strength steel (UHSS) sheets to manufacture real automotive components usually produced with the conventional cold-roll forming process was evaluated. Finite element simulations incorporating the mechanical properties of plasticity and ductile fracture were conducted to validate the new process. The results demonstrated that the proposed forming process efficiently produced automotive components with consistent shapes and lengths, and the simulation outputs were in good agreement with the experimental data in terms of dimensional accuracy and quality. Additionally, sensitivity analyses of process parameters such as friction and die design provide valuable insights for optimizing the newly proposed formation process of UHSS sheets.

Experimental validation of IS2062 deep drawing component

Deep drawing isa leading manufacturing method in which a sheet metal blank is radially stretched into a die by action of a punch to produce various parts of automobiles, computers, electronic items and many other things used in day-to-day life. Optimization of sheet metal forming process parameters was important to reduce the cost of manufacturing a product. Forming a defect-free drawn part is always a challenging task. This work presents analysis and experimental identification of the deep drawing process in order to avoid earring effect and Stretcher strain defect. In our present work, low carbon structural steel (IS2062, Carbon 0.17 to 0.19 wt%) is used for deep drawing application. Factors mainly influencing the friction coefficient, blank holder force, and die nose radius, which are the sheet metal process characteristics that exhibit deformation behaviour. In an experiment, radial clearance between the die and the punch was taken as 0.15 mm on each side. Deep drawing operation was carried out on a 1200 ton hydraulic press with a servo controlled mechanism, a 3 stage forming process was taken and values were compared with the FEA, A cylindrical cup with a LDR of 1.8 has been successfully created experimentally.

Performance of stringer sheet parts under static and dynamic load

The stringer sheet forming process chain enables the cost-effective production of components with significantly increased stiffness for mass markets such as the automotive sector. In the first process step, a stringer is added to a conventional sheet by laser welding. In the subsequent process step, the stringer sheet parts are formed by a deep drawing operation. Previous investigations of component performance focused in particular on the static stiffness of the stringer sheets. The behavior under dynamic load, such as in crash events, has not been systematically investigated to date. Static testing focused on the stringer height as the only influence on part performance. This study characterizes the crash performance of stringer sheet components by means of a drop hammer test. The energy absorption of the components is evaluated in the experiment based on the rebound height of the drop hammer, whereas the structural integrity is characterized based on the maximum dynamic as well as permanent deformation. Furthermore, a quasi-static compression test is carried out to obtain the static stiffness of the parts. In these tests, the geometric design of the stringer sheets as well as two forming process parameters are varied individually. The influence of these parameters on the static stiffness, energy absorption and structural integrity is assessed and discussed on their own and with regard to their influence on the part weight.

Characterization of the Tribological Behavior of Different Tool Coatings and Dry Lubricant for High‐Strength Aluminum Alloys at Elevated Temperatures

The use of high‐strength aluminum components in automotive manufacturing offers the opportunity to reduce vehicle weight significantly and provide new lightweight potentials. In the past, the so‐called hot forming and quench process (HFQ) successfully demonstrates the potential for the production of complex‐shaped components made out of age‐hardenable high‐strength aluminum alloys. Currently, no method permits wear‐free quench forming without the use of lubricants. To fulfill the increasing ecological and economic requirements, it is necessary to identify wear‐reducing techniques to promote this forming technology in the future. This contribution investigates the interaction of lubricant and tool coatings on the tribological performance during quench forming of the high‐strength aluminum alloy AA7075 at elevated temperatures. For this purpose, the tribological behavior is investigated using both, flat strip drawing tests and deep drawing operations. Subsequently, the component quality is compared and discussed. The results demonstrate that tool coatings are effective for the production of high‐strength components in the HFQ process with minimal or even no lubrication and thus provide ecological as well as economic advantages.

Double-diffusive Hamel–Jeffrey flow of nanofluid in a convergent/divergent permeable medium under zero mass flux

In the recent era, the nanofluid's transportation due to the Jeffrey–Hemal flow phenomenon (i.e., carrying fluid through a converging/diverging channel) has significant applications in numerous engineering and science technologies. Therefore, multi-disciplinary evolution and research motivated us to present current attempt. The aim of this attempt is to present Jeffrey–Hamel mechanism of the nanofluid through non-parallel channel under thermally balance non-Darcy permeable medium impacts. The nanomaterial is represented using the Buongiorno nanofluid model. The investigation also includes zero mass flux impacts as well as variable rheological fluid properties. The influences of temperature jump are also encountered in the current analysis. The governing flow expressions under the Jeffrey–Hemal analysis are made dimensionless utilizing the similarity variables. The dimensionless equations are then solved using the analytical scheme (homotopy method) and the obtained series solutions are convergent. The influences of the involved parameters on concerned profiles are investigated through graphs. Force of drag, Nusselt and Sherwood numbers are elaborated graphically. In this analysis, intensification in Prandtl number enhances the heat transfer rate whereas decrement is seen in heat transfer rate for larger thermal slip parameter. Further, mass diffusivity parameter adversely affects the mass transfer rate. The current analysis incorporates numerous industrial and technological processes including transportation, material synthesis, microfluidics, high-power Xrays, biomedical, solid-state lighting, microelectronics, scientific measurement, medicine, molten polymers extrusion via converging dies, cold drawing operation related to polymer industry etc.

Experimental and Theoretical Analysis to Produce Pentagonal Cup in Deep Drawing Process

The manufacturing industry heavily relies on deep drawing due to its remarkable ability to produce intricate symmetrical and asymmetrical shapes with accuracy and efficiency. This research aimed to create a deep drawing tool capable of producing a pentagonal cup measuring 41mm in diameter and 30mm in height. This was achieved by conducting numerical simulations and experimental tests using two different methods. The first method involved converting an 80mm diameter circular blank into a pentagonal cup through a drawing operation, while the second method involved redrawing a cylindrical cup into a pentagonal shape. The study also analyzed the impact of these methods on the drawing load, stress/strain distributions, and thickness distributions. The finite element method software, ANSYS 20, was employed for numerical simulations. The results showed that the first method had a significantly higher punch load than the second method. However, the pentagonal cup produced using the first method had a greater thickness reduction towards the cup wall curvature compared to those produced using the second method. Therefore, the second method was considered ideal for manufacturing a pentagonal cup because it resulted in a lower degree of thinning at the cup curvature and a more uniform distribution of thickness, stress, and strain. In conclusion, this research highlights the importance of deep drawing in the manufacturing industry and emphasizes the need to choose the appropriate forming method to achieve optimal results.

RESEARCH OF THE MICROHARDNESS OF THE SURFACE OF A CYLINDRICAL PART DURING DEFORMATION

It is known that when processing plastic materials by cutting, chip grinding is a serious problem. The formation of a stable, strong draining chip is a sign of low machinability of the material of the part and requires the use of special means and methods that would ensure the separation of the chip or allowance that is cut. This issue is especially relevant in the case of cutting drawing as a low-speed process, which is characterized by intensive overgrowth and a high coefficient of chip shrinkage, and therefore the strength of the latter. Today, there are a number of original developments of several scientific schools, which implement the idea of preliminary division of the allowance during drawing by creating a network of technological chip-splitting grooves. The process of internal drawing, in particular drawing of round deep holes, must necessarily take place under conditions of forced chip separation or allowance. At the same time, the so-called transverse division of the chips, i.e., division along the perimeter of the hole, is usually carried out due to structural elements on the broach teeth and today is not too difficult a problem. However, there are certain reserves in this direction as well, in particular those related to increasing the stability of the tool. This article considered the technological function of the reliefs, which consists in the forced division of the cut allowance with contour grooves. An analysis of the advantages and disadvantages of the most common processes for obtaining round holes in hollow blanks and parts is carried out. The essence of the group (progressive, variable) stretching scheme is described. Typical combined extension tools are considered. Given formulas for calculating the dimensions of chip grooves. The first component р of the change in the diameter of the hole and the outer diameter of the workpiece after each of the combined drawing operations is characterized.

Sheet-Metal Formability Study on a Circular Tube with a Folding Bottom Feature

The formability of sheet-metal with a folding-bottom circular hollow tube has been studied both by numerical simulation and experiment. A mesh-convergence analysis has been carried out to determine an optimum element size for purposes of numerical simulation. The geometry and dimension of the dies and of the punch are designed to simulate the multi-stage deep drawing operation to take place. During the deep drawing operation, the strains of the sheet blank are always located in the second quadrant of the forming limit diagrams, and it continuously moves in a linear state to the left side of the diagram. At the final stage, the tube is drawn to a certain height without evidence of fracture. In order to obtain a quality product, an optimization of input parameters for the deep drawing operation is conducted using Taguchi method. Finally, a validation test is also employed to demonstrate the accuracy of forming processes. The result reveals sufficient agreement in both geometry and dimension between simulated and actual tubes to meet a good quality standard.

Análisis de la formabilidad de láminas de acero AISI 304 con diferentes espesores mediante sus propiedades de tracción

Although AISI 304 steel is widely used and its manufacturers provide resistance data in the quality certificate, these are not sufficient to characterize and predict the behavior of the sheets in the drawing and drawing processes. This is why the objective of this work was to analyze the formability of AISI 304 steel sheets with 16- (thickness 1.5 mm), 18- (1.2 mm), and 20- (0.9 mm) gauges used by the metalworking industry in Colombia by determining intrinsic properties related to the ability of the sheet to withstand stretching and drawing operations such as the strain hardening exponent n, the normal anisotropy rm, and the planar anisotropy Δr. The methodology consisted of analyzing the chemical composition, a metallographic study, and a series of tensile tests. The results show that the steel has a microstructure of twinned austenite grains of size between 15-30 mm. Regarding the mechanical resistance, it was observed that all the mean values of ultimate resistance, elastic limit, and elongation are above the minimum established in the standard. Furthermore, all of the tensile test results changed according to the variation of angles concerning the rolling direction (0°, 45°, and 90°), which indicates the anisotropic character of the sheet. The most relevant result allows us to infer that the 20-gauge sheet has better formability and therefore, better behavior against the stretching and drawing processes.