Die Design Research Articles

Die design parameters effect on dimensional conformity of PEM fuel cell bipolar plates in rotary forming of SS316L thin sheets

Rotary forming is a promising technique for high-volume, low-cost production of fuel cell components such as bipolar plates, but it needs to be better characterized for this application. In this paper, die design parameters in rotary forming of ultra-thin stainless steel 316 L sheets 100 μm thick are evaluated to explore how channels perpendicular and parallel to the rolling direction are affected by critical forming process parameters, namely depth of deformation, die corner radius, and friction coefficient. Channels are formed experimentally, and the results are used to verify the 2D and 3D simulations. The process is analysed in terms of die movement path and forming. Stress, strain, formed shape, and thickness are compared for the two main forming directions. Results showed that channels formed parallel to the rolling direction experience more plastic deformation and conform better to the prescribed geometry in terms of channel and flatness angles.

Analysis of Titanium Mesh Ti6Al4V Formation Using Die Press Forming Machine for Cranioplasty

Cranioplasty is required for patients with head defects, where the deformed part of the head is replaced with Ti6Al4V titanium wire implants. The titanium wire forming process is usually done manually, which can take a long time and give results that do not match the anatomical shape of the head. Therefore, it is important to develop domestic technology that can produce titanium wire automatically. This study aims to analyze the frame and mold of the automatic wire mesh molding machine before production. The tool is made using press forming method and finite element analysis with ANSYS software. The machine frame is made of 304 stainless steel material, while the mold uses ABS material. The analysis was performed with a constant load force of 100 N, corresponding to the maximum reading on the load cell. The simulation results show the deformation, strain, and von Mises stress of the machine frame and punch model, which are still far below the plastic deformation and UTS values of the material. However, the analysis results on the Ti6Al4V titanium die and mesh exceeded the UTS of the material in the cutting edge area of the die. Nevertheless, the die model can still be used because the maximum stress point is located at the edge of the die design area, where the titanium mesh will be cut when applied to the patient's skull implant. The results of this study are expected to help medical personnel in skull implant surgery and analysis of press machine manufacturing.

Extrusion Benchmark 2023: Effect of Die Design on Profile Speed, Seam Weld Quality and Microstructure of Hollow Tubes

The Extrusion Benchmark 2023 was focused on the evaluation of different die design strategies for the manufacturing of AA6082 hollow tubes (40 mm external diameter and 4 mm thickness) through a porthole die with 3 openings. The extrusion process was monitored in industrial environment in terms of press load, profiles speed, profiles exit temperature, and die temperatures under different processing conditions (air quenching, water quenching, nitrogen die cooling). Extruded profiles were then analyzed in terms of seam weld quality, charge weld extension and microstructure evolution for both air/water quench and presence/absence of nitrogen cooling. The results of the study are aimed at validating FEM simulation outputs in the context of the International Conference on Extrusion and Benchmark (ICEB).

Automated Optimum Extrusion Die Design and Profile Quality Control Based on Simulation

The paper presents the experience of development and implementation of an integrated approach of extrusion simulation with the automated design of the dies as a new way to speed up the technology development and its optimisation based on the QForm UK Extrusion simulation program and QForm Extrusion Die Designer (QExDD) design system. Bearing and prechamber optimisation types are considered for the porthole design. Welding quality and possible streaking lines in the profile are analysed for the tool construction with optimised prechamber contour.

Die design optimization for connecting rod using simulation modeling and taguchi methodology

This paper presents a novel approach to optimizing the die design for forging used in connecting rods. The combination of Taguchi (orthogonal L9) and the finite element method (FEM) was employed to achieve this optimization. The main objective of this study was to analyze the impact of design parameters on die-filling and yield improvement. The orthogonal L9 design was generated with three input parameters and one response variable. These input parameters were derived from the design dimensions of the forging tool, specifically flash land, draft, and flash thickness. The response variable was the maximum yield percentage, which was obtained through finite element simulations of the forging processes. By conducting an orthogonal analysis, the relationships between the response variable and the input parameters were established. The simulation results were then used to compare the outcomes of two different designs. It was found that preform one outperformed the other design, achieving an impressive yield of 88% at a forging load of 1.37 × 104 N, with complete die filling observed.

Discretized blank holding force driven by electromagnetics: Mechanism of thermal effects and deformation

Electromagnetic blank holding for forming complex parts has received considerable attention due to the flexibility in die design and force control. However, electromagnetics experience overheating with continuous current loading for traditional variable blank holding force, which restricts widespread and long-term applications. The discretization of the blank holding force was first proposed to solve this issue, where mechanisms of thermal effects and the deformation of the part with the discrete current loading, which is significant for high-quality forming, remain to be further clarified. This study established a general thermal model for multi-poles in electromagnetics using Fourier's law of heat transfer. The temperature variations in different discretization levels of force were revealed by simulation and experiments. The appropriate discrete level of the force was applied to the forming process of the sheet material, reflecting the law of its influence on the deformation. With optimized discretization blank holding force, high forming accuracy was observed in forming thickness and microstructure tests. Results indicate that the discretization blank holding force can keep the die at a much lower temperature and is promising for improving the forming accuracy of the part. This work assists in designing the blank holding force and electromagnetic die for better forming and efficiency in long-term production.

Integration of soft tooling by additive manufacturing in polymer profile extrusion process chain

Integrating additive manufacturing (AM) into polymer extrusion offers process chain flexibility and design freedom. It reduces the need for time-consuming iterations and trial-and-error in the die design process. Consequently, polymer AM of extrusion (i.e., soft tooling) allows for a shorter product development cycle and cost-effectiveness for small-scale production and highly customized products. In this study, carbon fibre (CF)-polyether-ether-ketone (PEEK) dies were manufactured using the fused filament fabrication (FFF) AM process, employing a streamlined die design achieved through freeform transition planes. Calibration slides were produced using masked stereolithography (MSLA), FFF, and conventional manufacturing techniques (i.e., machining) to preserve the final product’s cross-section during the cooling process. The dimensional and surface characteristics of these calibration slides were evaluated to assess the dimensional accuracy and surface topography of various materials and manufacturing processes. The dimensional evaluation reveals that MSLA-printed parts exhibit deviation from the nominal dimension closer to the conventionally manufactured part. The integrated soft tooling in the polymer extrusion line was tested with polypropylene (PP) and acrylonitrile butadiene styrene (ABS) as extruded materials. The surface topography of the CF-PEEK die displays distinctive ripple features resulting from the FFF process, identified by relatively flat peaks and deep valleys. The overall surface texture parameter values of CF-PEEK were higher due to the presence of deep valleys. Considering that the areas around the peaks interacted more with polymer molecules during the extrusion, the surface texture parameters of the extrudates were closer to the value observed in 90 µm region areas around the peaks. Notably, extrudates of AM calibration slides have lower surface texture parameters than extrudates of conventionally manufactured calibration slides, even though surface defects in the form of dimple sink marks were observed in extruded material of PP from extrudates using AM calibration slides.

Design and Manufacturing of Compound Die

Abstract: The work deals with the development of a combined tool for improvement of a process to be done in piaggio product manufacturing plant. Research work deals with combining two press operations done separately. This operation is done for piaggio battery support bracket, cradle assembly, Bumper cargo. In the first pressing blanking process is done. And in the second operation a hole is pierced in the same product. The objective of research is to develop a tool and process for using a single press for performing dual operation. This is also to reduce downtime, reduce operator fatigue and thereby increase production. Elimination of one operation, one operator and reduction in processing time is also to be achieved.

Development of Low-Weight and High-Strength AA6005A Extrudates Intended for Modern Architecture and Design of Innovative Die for Extrusion Process.

In the realm of modern architecture, the demand for materials that combine strength, durability, and aesthetic flexibility is ever-growing. Addressing this need, this paper presents a study on the innovative use of aluminum extrudates in construction. Focusing on the AA6005 alloy, which is known for its excellent balance of strength, corrosion resistance, and weldability, this research delves into the development of an extrusion process that yields thin-walled, lightweight, yet high-strength structural components. Using FEM simulations, a new extrudate of the AA6005A was developed. It is compatible with standard façade systems, with high-strength properties and a weight reduced by 20% compared to that of conventional extrudates made of the AA6063 alloy. Using CAD engineering and FEM simulations of aluminum extrusion process, an innovative die was designed for the extrusion process, ensuring uniform flow of metal from the bearing and minimizing the elastic deflection of the die. This resulted in an increase in the extrusion velocity of thin-walled extrudate from AA6005A by 24% compared to conventional profiles extruded from AA6063. As part of the research, a trial test was carried out in production conditions and the quality of the extrudates was tested by 3D optical scanning, mechanical and structural properties tests, and microstructure observation.

Advancing Die Design and Optimization through the Combination Approach: A Focus on Spring-back Compensation

This study explores the geometrical deviations that occur in cold stamping, which are caused by the spring-back effects in elastic metals after forming. The primary aim is to introduce and assess the Combination Approach. This approach seamlessly integrates the Displacement Adjustment and Spring Forward methods for die compensation. This multi-stage process meticulously corrects dimensional errors and effectively reduces spring back through iterative processes. Using the NUMISHEET model, numerical simulations have shown a significant reduction in spring back errors, with up to a 55% reduction achieved with optimized die surfaces after five iterations. The proposed Combination Approach improves the accuracy of die design and contributes significantly to the stamping industry by incorporating established techniques within finite element software. This research broadens the scope of die compensation strategies, creating new opportunities for achieving precise die design in stamping.

Die Design and Forging Analysis of Piston Connecting Rod of Aluminum Alloy

The piston connecting rod is an indispensable in the internal structure of the automobile. As one of the important components in the internal combustion engine system, the piston connecting rod needs to meet the requirements of high fatigue and impact load resistance. Forged piston connecting rod can obtain high strength and fatigue resistance. In this study, the parting line, draft angle, forging tolerance, die fillet radius, shrinkage and scrap are considered in the design of forging die. The process parameters and die dimensions of the forging process of aluminum alloy piston rod are simulated by finite element analysis. The aluminum alloy piston rod with high dimensional accuracy is then forged according to the finite element simulation results.

Influence of the Forming Die Design on Processing and Physical Properties of Gluten-Free Crisps

Abstract The aim of the research was to evaluate the influence of the forming die openings shape on processing parameters of the extrusion-cooking process and on the selected properties of gluten-free crisps. The experiment used blends of corn grits, unroasted buckwheat, rice, and dried blackberries. The extrusion process of gluten-free crisps was carried out via a prototype EXP-45-32 single-screw extruder with L/D=16. During the tests, 5 different forming dies were assessed: 2 openings with a diameter of 2 mm each, 1 round opening with a diameter of 3 mm, 1 cross-shaped opening, a star and a heart. During the tests, the processing efficiency and energy consumption of the extrusion process were tested, and the expansion index, bulk density and hardness of the crisps were investigated. The research demonstrated that the forming die shape affects the efficiency and energy consumption of the extrusion-cooking process of crisps. The lowest efficiency was found if a heart-shaped die was used, and the highest efficiency was determined in the case of a star-shape die. Moreover, the highest specific energy consumption was noted when using a star-shaped die during crisps extrusion. Crisps obtained using dies with larger diameters were characterized by a lower expansion index. The complicated shape of the die opening resulted in less expansion of the obtained crisps. The highest bulk density and hardness were found in the case of crisps obtained on a star-shaped forming die.

Implementation of Continuous Improvement to Increase the Efficiency of the Production Process through Press Dies Design

In the manufacturing industry, there are companies that operate in the metal forming sector. Many products are produced by the metal forming process, one of which is the packaging box lock hook. The key hook is a component part of the packaging box which functions as a hook so that the packaging box can be closed and locked. In the production of key hooks there is waste, namely over processing, which reduces the efficiency of production time. To reduce this problem, improvement efforts were made by implementing continuous improvement using the DMAIC method. Continuous improvement steps are carried out by direct observation in the field to find problems. After that, measurements and analysis are carried out to determine improvements that will be implemented. Then the improvement stage was carried out as an implementation of continuous improvement. Continuous improvement resulted in a press dies design for the key hook piercing process. By designing new press dies, production time efficiency will be achieved. After carrying out Continuous Improvement, it resulted in an increase in the efficiency of the number of processes from 6 processes to 5 processes and the total production time in 1 cycle from 13.3 hours to 11.4 hours or 1.9 hours faster or an increase in efficiency of 13.3 % of the total time before Continuous Improvement. And 50% increase in sub piercing process.

A comprehensive review on state-of-the-art applications of case based reasoning in aluminum foundries

An Aluminium Foundry offers multiple opportunities for implementing expert systems across various domains, including component design, process planning, rejection reduction, and determining parameter values for Die-to-Die Design to achieve cost benefits. Considering the projected growth of the Global Aluminium Die Casting market at a 15 percent CAGR until 2025, one of the key hurdles to this growth lies in the requirement for substantial investments. This paper explores the diverse applications of expert systems in different aspects of aluminium casting, focusing on the utilization of Case-Based Reasoning (CBR) systems within Aluminium foundries. Case-Based Reasoning, a problem-solving approach, leverages past cases resembling the current problem to guide solutions for new challenges. The review encompasses various expert systems applied in aluminium casting and specifically highlights the application of Case-Based Reasoning systems. Additionally, it identifies gaps within the Die Design Support System for Gravity Die Casting utilizing Case-Based Reasoning, aiming to delve deeper into this particular area for potential improvements.

Optimizing New Power Switch Technology

Power switches are critical components in power conversion for a wide variety of applications, including DC-AC inverters for electric vehicles (EVs), solid state breakers, and energy storage devices. Improving the efficiency and performance of semiconductor power switch components can have wide benefits, improving the efficiency and accelerating deployment of these applications. Compared to conventional power switches, such as insulated-gate bipolar transistors (IGBTs), the B-TRAN™ bidirectional power switch from Ideal Power offers significant improvements in efficiency, reducing power losses by 50% or more depending on the application. With its higher efficiency, B-TRAN results in less heat being generated and thus has significantly lower thermal management requirements. In addition, a single B-TRAN™ replaces multiple conventional power switches for bidirectional applications. Beginning in mid-2020, Ideal Power teamed with QP Technologies, a leading provider of microelectronic packaging and assembly services, to package their B-TRAN switches in various TO packages (a wide range of small-pin-count packages often used for discrete parts such as transistors or diodes). The development work started with TO-247, then moved TO-264 packages, and finally transitioned to a custom direct-bond copper (DBC) solution. To achieve a high-reliability design, QP Technologies and Ideal Power focused on developing die and packaging designs based on flip-chip technology in lieu of wirebonding to maximize the life cycle of the product. This paper investigates the challenges, solutions and finally the fabrication of the first double-sided B-TRAN device.

Accelerated multi-property screening of Fe–Co–Ni alloy libraries by hyper-heuristic combinatorial flow synthesis and high-throughput spark plasma sintering

High-throughput (HT) chemical synthesis facilitates accelerated materials discovery products. However, HT methods are limited by the need for expensive robotic systems, complicated methodology, and low yield. Hence, we developed a hyper-heuristic combinatorial flow synthesis (HCFS) device capable of composition gradient generation and production of an adequate mass of Fe–Co–Ni alloy nanoparticles. A library of 91 Fe–Co–Ni powder compositions was synthesized using this technique. A high-throughput spark plasma sintering (HT-SPS) methodology, along with the die design, was developed for combinatorial screening of multiple properties. 56 compositions were down-selected and consolidated into compositionally graded bulk samples using HT-SPS and subsequent annealing. The crystallographic, magnetic, electrical, and magnetic properties of the bulk library were assessed. The saturation magnetization (Ms) varied from 83.3 emu/g to 225.2 emu/g, coercivity (Hc) from 17.5 Oe to 78.4 Oe, resistivity (ρ) from 17.2 μΩ·cm to 986.7 μΩ·cm, and Vickers hardness (HV) from 41.9 HV to 281.7 HV. Novel Fe–Co–Ni compositions, e.g., Fe36.5Co55.1Ni8.4 and Fe22.6Co73.4Ni4, with a promising multi-property set, were identified for the first time. This study demonstrated that promising new compositions exhibiting multi-property optimization can be successfully discovered by our hyper-heuristic combinatorial chemical synthesis methodology.

Positional trueness of three removable die designs with different root geometries manufactured using stereolithographic 3D printing

Statement of problemThree-dimensional (3D) printed casts are a suitable alternative to dental stone casts. Contemporary dental design computer programs permit designing definitive casts with removable dies with different root geometries and retention mechanisms. Studies on the positional trueness of 3D-printed removable dies with different root geometries are lacking. PurposeThe purpose of this in vitro study was to investigate the 3D displacements of three 3D-printed removable die designs with different root geometries. Material and methodsThe digital file of a dental stone alveolar cast with root-form removable dies (MOD UJ IV Fixed Prosthetics; Ivoclar AG) was used as a reference to create 3 removable die and alveolar cast designs (Root Form, RF; Conical, CON; Cylindric, CYL) with different root geometries in 2 dental design computer programs (DentalCAD 3.1 Rijeka; exocad; GmbH; InLab CAD 22.0; Dentsply Sirona). 3 equidistant Ø1-mm spheres (C, Cervical; M, Middle; O, Occlusal) were designed on the buccal surface of the coronal portion of the removable die to evaluate their displacement. A total of 45 alveolar casts with 45 removable dies were fabricated using a stereolithographic 3D printer (Form 3; Formlabs); each die group consisted of 15 specimens. After fabrication and postprocessing, the specimens were scanned, and their digital files were analyzed in a metrology-grade computer program to evaluate the displacement of the removable dies with respect to the position of the die in the master reference file. Subsequently, the data were analyzed using a 3-way analysis of variance (ANOVA) followed by step-down Bonferroni-corrected pairwise comparisons (α=.05). ResultsTwo statistically significant 2-way interactions were detected between the independent variables, die design and direction (P<.001), and location and direction (P<.001). The post hoc analysis identified significant differences between the displacement values of RF and CYL (P<.001) and RF and the CON (P<.001) designs on the Y axis. The measured displacements were statistically different between the C and O locations on the Y axis (P=.001) and the M and O locations on the Z axis (P=.006). ConclusionsThe root geometry of a 3D-printed removable die and alveolar cast can affect seating, and variable degrees of tipping of the removable die can be seen. The seating and congruence of the removable die with the interocclusal space and relationships observed intraorally should be confirmed before adjusting indirect restorations.

Retracted: Process Optimization and Die Design of Hydromechanical Calendering Based on Wireless Network Communication and IoT

Retracted: Process Optimization and Die Design of Hydromechanical Calendering Based on Wireless Network Communication and IoT

A novel method for ball forming by cross wedge rolling

In this paper, a novel method for ball forming by cross wedge rolling (CWR) was proposed, and the finite element (FE) simulation and experimental verification were carried out with the 26 mm diameter steel ball as an example. First of all, the die parameters including spreading angle β and forming angle α were selected and the 3D models of the die and guide plate were designed. Then, the FE model was established and preliminary simulation was carried out using the Simufact 16.0 software. The preliminary simulation results showed that the pushing empty defect occurred in the process due to lack of transition from spreading stage to sizing stage and conical die section. Modifying the die design by adopting the method of adding transition spreading angle θ and forming angle α´ increasing with the increase of rolling depth to, the defect could be eliminated and the full filling can be obtained. In addition, the simulation analysis after modified also included effective strain and stress distribution, the kinematic analysis of metal flow, the damage distribution based on the Cockcroft-Latham criterion, the temperature evolution and force parameters in the CWR process. Finally, the rolling experiments and radial rolling force testing experiments were carried out to verify the numerical results. The results indicated that the FE simulation results were consistent with the experimental results through quantitative analysis, which proved that the novel method for ball forming by CWR was feasible simultaneously.

Design of Dies of Minimum Length Using the Ideal Flow Theory for Pressure-Dependent Materials

This paper develops the ideal plastic flow theory for the stationary planar flow of pressure-dependent materials. Two rigid plastic material models are considered. One of these models is the double-shearing model, and the other is the double slip and rotation model. Both are based on the Mohr–Coulomb yield criterion. It is shown that the general ideal plastic flow theory is only possible for the double slip and rotation model if the intrinsic spin vanishes. The theory applies to calculating the shape of optimal extrusion and drawing dies of minimum length. The latter condition requires a singular characteristic field. The solution is facilitated using the extended R–S method, commonly employed in the classical plasticity of pressure-independent materials. In particular, Riemann’s method is used in a region where all characteristics are curved. It is advantageous since determining the optimal shape does not require the characteristic field inside the region. The solution is semi-analytical. A numerical procedure is only required to evaluate ordinary integrals. It is shown that the optimal shape depends on the angle of internal friction involved in the yield criterion.