Die Design Parameters Research Articles

Optimization of die design parameters in ECAP for sustainable manufacturing using response surface methodology

Optimization of die design parameters in ECAP for sustainable manufacturing using response surface methodology

Experimental validation of machine learning models for prediction of the thickness distribution of directionally rolled copper strips under scaling law

Predicting the results of multi-stage deep drawing in determining the thickness distribution and thinning of the workpiece are measures that will help reduce production costs by saving materials and production time. Machine Learning (ML) technique is a promising method for predicting the thickness distribution (TD) of drawn copper metal. Macro and micro products are currently used in sensitive electronic and structural applications. In this study, ML defines the relationship between the scaled thickness and the respective number of stages governed by the scaling law. It includes the development of Artificial Neural Network (ANN) tools based on machine learning to model the relationship between thickness by scaling law and stages based on multi-stage deep-drawn cups. TD is a measure of consistency. The TD is measured from the initial blank of 1500 mm long, 750 mm wide, and 6 mm thick Cu strip, reduced by 50% in nine successive steps until a final thickness of 0.1875 mm. Two ANN models used for TD prediction are Bayesian regularization (BR) and Levenberg-Marquardt (LM) algorithms. A trained machine learning model can successfully predict and verify the unseen data of 1.5 and 0.38 mm TD. ANN is used to predict the Finite Element Analysis (FEA) results and confirm them through the experimental results. The developed model can predict the TD of the multi-stage cup with the die design parameters. The difference between the TD predicted value and the measured value is based on the simulation results of multi-stage cups using the finite element method. When the predicted and measured TD, the difference in cup drawing depth is 0.5%–2.0%. The results show that the LM model is suitable for predicting the TD of formed copper cups following the scaling law.

An experimental and numerical investigation of the role of rivet and die design on the self-piercing riveting joint characteristics of aluminum and steel sheets

We analyze the role of different rivet and die design parameters on the feasibility and quality of the self-piercing riveting (SPR) joining of metallic sheet stacks. In particular, the riveting of a similar aluminum-to‑aluminum sheet stack (AA2019/AA7075-F) and a dissimilar aluminum-to-steel sheet stack (AA7075-F/BA0270) is investigated, both experimentally and numerically. Towards this, the different rivet and sheet materials are experimentally characterized to obtain their elastoplastic and fracture attributes. Thereafter, SPR process finite element models are developed. Initially, the joint feasibility is experimentally probed for specific available rivet and die configurations, thus identifying SPR process parameters that allow for successful joining. Thereafter, a wider range of SPR process parameters is investigated numerically. It is observed that a combination of successful joint formation and high interlock values is obtained over specific ranges of rivet leg thickness and die depth values. Moreover, low rivet leg thickness values and near-unity normalized die depths – with the sum of the die depth and total sheet thickness normalized with respect to the rivet leg length – yield high quality SPR joints for both types of stacks considered. However, the optimum parameter selection is stack-specific, with high-quality AA2019/AA7075-F SPR joints observed to be feasible over a more constrained parametric space compared to the AA7075-F/BA0270 joining case. Further, it is concluded that the mean von Mises stress induced in the sheets after the SPR process is primarily affected by the selection of the die depth, with the induced stress being less sensitive to other design parameters, such as the rivet leg thickness or die shape for both joining cases. • The joining of Al-Al (AA2019/AA7075-F) and Al-Steel (AA7075-F/BA0270) sheets is experimentally and numerically investigated. • Rivet and die material and geometric parameters allowing for successful joining are identified. • Combinations of rivet leg thickness and die depth values that favor high interlock joints are provided. • The effect of the rivet and die design on the induced Von Mises stresses is analyzed.

Design Parameters for Equal-Channel Angular Pressing (ECAP) Via Numerical Approach

A numerical approach utilizes to investigate the optimal die design parameters of the ECAP technique. The Deformation behavior and strain distribution are affected by die geometry and processing parameters. were analyzed and evaluated. In addition, the influence of the inner channel angle (ICA) and the outer channel angle (OCA) on the behavior of plastic deformation during ECAP process also studied using a finite element technique. The numerical investigation implemented over a range of die angles (90°, 110°, and 135°) with inner corner radius (0, 3, 4, 5, and 8 mm) with their corresponding values considered for the outer corner radius (0, 10, 12,14,15 and 20 mm). The results obtained regarding the force required, maximum stress, maximum strain, and equivalent stress evaluated over a range for die inner angle radius and die outer angle radius. These results show that the size of the inner and outer curvature radii has a big effect on deformation homogeneity of the billet. had an influence on both the quantity and distribution of effective strain. With the increment of inner and outer curvature radii, the effective strain value decreased in the deformation regions. Moreover, the optimum conditions in terms of strain distribution and homogeneity of billet are associated with a radius of the inner fillet of 4 mm and radius of outer corner of 12 mm. The impacts on the von Mises strain and the press force. The optimal compromise between applied force and von Mises strain balances small press forces and high von Mises strain and homogeneity indices.

Effect of Die Design parameters on materials processed by Equal Channel Angular Pressing

Equal Channel Angular Pressing technique is used for grain refinement in bulk materials, where the material is passed through the die in which the two channels intersect at some angle, that result in finer grains. There are number of die design parameters which affects the production of ultra-fine grains. This paper presents the effect of die design parameters such as channel angle, corner angle, several passes and route followed for processing of the material for grain refinement. The results of different parameters are compared, and it was observed that the optimum values for producing maximum shear strain is for channel angle 90° and it reduces with the increase in channel angle. About 20° corner angles is found to suitable for filling the corner gap, around 4 to 6 passes, and route Bc leads to the ultrafine grained structure of homogeneous equiaxed grains separated by high angle grain boundaries in the materials. The sample of Al-TiO2 was prepared and its microstructure and mechanical properties were tested after equal channel angular pressing.

Mechanical behaviour of Aluminium Alloy AA6063 processed through ECAP with optimum die design parameters

ABSTRACT Equal Channel Angular Pressing (ECAP) is one of the most effective techniques for the formation of ultra-fine grained bulk material. The material is passed through the channel in the specially designed die in the ECAP process. The die design parameters like corner angle, channel angle and other parameters play an important role in the formation of ultra-fine grains. The die with optimum design parameters, with channel angle 90° and corner angle 20°, was designed and fabricated in the laboratory and commercial Aluminium AA6063 was used as sample material to investigate the mechanical behaviour/properties before and after the ECAP process. In the present work, the mechanical behaviour of commercially pure Aluminium processed by ECAP die with an optimum die design parameter is studied and examined. The path adopted was BC and pressing was done from 0 to 3 numbers of times. The results revealed that the grain size reduced from 530 to 220 nm and tensile strength increases from 275.8 to 368.4 MPa after three numbers of ECAP passes.

The impact of upstream contraction flow on three-dimensional polymer extrudate swell from slit dies

The relevance of upstream contraction for extrudate swell behavior of polymer melts is numerically investigated for slit dies with an aspect ratio of 10 and a length-to-height ratio ranging from 2.5 to 40. Three-dimensional (3D) flow simulations are performed with ANSYS Polyflow software at different flow rates and a constant temperature of 200°C, selecting a differential multimode Phan-Thien-Tanner (PTT) constitutive model to describe the viscoelastic behavior of polypropylene. It follows that decreasing the die length results in an opposite trend of the swell ratio in the width and height directions. The width swell ratio decreases up to 28%, whereas the middle height swell ratio increases up to 55% and the edge height contraction increases with 37%, all highlighting the 3D anisotropy of the extrudate swell deformation. However, especially for low flow rates, the area swell ratio remains almost unchanged and cannot be used to capture the anisotropic swelling behavior. This is predominantly attributed to the similar relative redistribution degree of the axial velocity (vx). An analysis of the transversal (vy) and lateral velocity (vz) combined with the stress field variation is performed as well to fully relate the anisotropic extrudate swell behavior to the various die lengths. The current study therefore contributes to completing the understanding of the relation of slit die design parameters and 3D extrudate flow under isothermal conditions, covering both developing and fully developed flow.

NUMERICAL SIMULATION TO STUDY EFFECT OF DIE DESIGN PARAMETERS ON DEFORMATION POSSIBILITY OF METAL ON COMBINED DRAWING

This paper uses numerical simulation to study amethod in combined drawing process with thinning the wall when drawing of a cylindrical cup of sheet metal. The software Deform 2D is used to examineeffect of die design parameters (inclination of die) on deformation possibility of metal. Simulation results in order to select appropriate die design parameters (conical die), to enhance the ability to deform and contribute to improve product quality.

Development of Mathematical Modeling and its Exploration Based on Genetic Algorithm for Blanking Die Design Parameters Optimization

The blanking operation have several die design parameters which affect the quality of the blank and its productivity. The main input parameters are sheet thickness and the punch and die clearance and the dependent output parameters are tool life and the burr height. The selected values should be in optimal value. The optimum value is achieved by using the genetic algorithm. The genetic algorithm is an optimization process to find the better results as an output. Then the development of mathematical modeling by using the equations derived from the multiple regression analysis is performed. It is achieved by converting the linear equations into the matrix form and then solving it using mathematical relations. This output is compared with the genetic algorithm results, to get the better results.

금형설계 변수에 따른 마이크로 티타늄 나사 전조공정의 성형 특성 고찰

금형설계 변수에 따른 마이크로 티타늄 나사 전조공정의 성형 특성 고찰

Experimental study and numerical simulation the air jet flow field of a dual slot sharp blunt die in the melt blowing nonwoven process

In this work, the physical model of a polymer in a melt blowing process is established and solved by introducing the numerical computation results of the air jet flow field of the dual slot sharp inset die. The influence of the melt blowing processing parameters and the die design parameters on the fiber diameter is also studied. A lower polymer throughput rate, higher polymer melt initial temperature, higher air initial temperature, higher air initial velocity, smaller angle between slot and axis of the spinneret, smaller width of the die head, and larger width of the slot can all produce finer fibers. At the same time, the air jet flow field model of the dual slot sharp inset die of polypropylene polymer nonwovens fabrics in melt blowing process was also established. The air jet flow field model was solved by using the finite difference method. The computational simulation results of the distributions of the z‐components of air temperature and air velocity along the spinline during melt blowing process are in accordance with the experimental data. The air drawing model of melt blowing process was simulated by means of the numerical simulation results of the air jet flow field. The predicted fiber diameter agree with the experimental data. The effects of the air initial velocity and air initial temperature on the fiber diameter were studied and discussed. The results demonstrate that a higher air initial velocity and a higher air initial temperature are beneficial to the air drawing of the polymer melt and thus to reduced fiber diameter. The results show the great potential of this research for computer assisted design in melt blowing nonwoven process and technology. POLYM. ENG. SCI., 57:417–423, 2017. © 2016 Society of Plastics Engineers

Optimization of Die Design Parameters in Blanking Operation Using Genetic Algorithm

Optimization of Die Design Parameters in Blanking Operation Using Genetic Algorithm

Effect of die design parameters on the deformation behavior in pure shear extrusion

Abstract Influences of die design parameters in terms of diameter ratio and length of the deformation zone on the distribution of effective strain, filling fraction of the die exit channel and pressing load in pure shear extrusion (PSE) are studied using finite element method (FEM). Dimensional stability, pressing load and hardness measurements are used to validate the predictions of the simulation. Acceptable agreements between the predictions of simulation and experimental results are observed. It is found that strain is inhomogeneously distributed which increases from the center to the corners. Effective strain, inhomogeneity of strain, filling fraction of the die exit channel and pressing load are increased with increasing diameter ratio. In addition, the work-piece is deformed more homogeneously at lower pressing load by increasing the length of deformation zone. However, filling fraction of the die exit channel initially increases by the length of the deformation zone up to 60 mm after which it reduces. The optimum die design parameters covering a range of acceptable effective strain and strain homogeneity, filling fraction of the die exit channel and pressing load are proposed as being 60 mm and 2 for length of the deformation zone and diameter ratio, respectively.

Effect of Processing Methods and Die Design Parameters on Green Properties of WC–Co Nanopowder Pellets

Non-uniform and unequal pressing of powder for making green pellet plays an important role in deciding structural properties of sintering pellets. Various parameters like surface roughness of the die, die-plunger clearance, and flatness of plunger/anvils are among the most important parameters to be taken care in making a proper die set. This paper presents a comparative study on quality of pellets formed using four different types of uniaxial powder compression dies with two different processing techniques. In the present study, it has been observed that the quality of pellet depends largely on the internal surface finish of die barrel, flatness of anvils and the clearance between die barrel-plunger/anvil, and the processing of powder before compression.

Working point of the EFG process

A theoretical investigation of the EFG process working point based on the meniscus height control is carried out. The link between the two control parameters, which are the pulling rate and the upper die temperature, is found from the thermal equilibrium at the crystallization interface. Using the pressure equilibrium in the film and considering the meniscus shape, the change in meniscus height depending on the crystal radius is analyzed. Limited to small crystal radii, an algebraic formulation of the temperature gradient at the interface is established. Some die design parameters are taken into account and their impacts on the process working point are discussed.

The influences of die structure parameters on extrusion force of manufacturing AZ31 magnesium alloy

Magnesium alloys as the lightest structural metal material are very attractive in various applications in automotive and aerospace industries. Direct extrusion is a common method to improve workability and strength of magnesium alloys and refine the grains structure. Researches have been done to simulate the direct extrusion process to manufacture AZ31 magnesium rods. The characterisations of the magnesium AZ31 alloy during extrusion have been concerned. The evolutions of extrusion forces affected by extrusion dies with different die structure parameters such as extrusion ratio, friction coefficients, radius of entrance, etc. have been predicted. Analysis of the die design parameters which affect the difference of the extrusion force shows that die structural parameters influence the extrusion forces remarkably. A group of optimisation parameters for die structures have been obtained from simulation results and used to extrusion experiments. AZ31 magnesium alloy billet can be extruded easily by using the optimisation process parameters in the extrusion experiments. Finite element methods have been used for the optimal design of the die to decrease the extrusion force caused by extruding magnesium alloy. The obtained results have illustrated that the extrusion force of direct extrusion for magnesium in the optimum curved die is reduced considerably.

Numerical study on die design parameters of self-pierce riveting process based on orthogonal test

The concave die design of self-pierce riveting (SPR) is of critical importance for product quality. The optimization of concave die parameters based on orthogonal test is proposed to explore the relationship between self-pierce riveted joint quality and die parameters. There are nine independent die parameter factors in orthogonal test and each factor has 4 levels. In order to evaluate the interlock and neck thickness, we carry out numerical simulations by the software DEFORM-2D. Then, the primary and secondary factors that affect the joint quality have been found out by means of range analysis. Finally, an optimization scheme is brought forward to design concave die in SPR process, which indicates that the joint has higher quality than that of former orthogonal tests. This work can be extended by a detailed mechanical and fatigue analysis for the joint quality of SPR process.

Alloy Selection and Die Design for Stamped Proton Exchange Membrane Fuel Cell (PEMFC) Bipolar Plates

Proton exchange membrane fuel cells have benefits over heat engines and batteries as an energy system for transportation, stationary power, and portable electronics. Before fuel cells can replace current energy systems, their manufacturing cost to performance ratio must be improved. The bipolar plate is a fuel cell component that contributes significantly to fuel cell manufacturing costs and is a key driver of performance. Metallic bipolar plates, with characteristic flow dimensions below the standard 1 mm, were fabricated using direct machining. Hydrogen/air fuel cells constructed of these plates were tested to ensure performance gains, using interdigitated flow operation and automobile-representative channel lengths. Finite Element Modelling (FEM) was used to investigate the manufacture of bipolar plates using low cost sheet metal stamping. Multiple bipolar plate alloys were compared based on their stampability, and die design parameters needed to stamp submillimeter channels were determined. Springback analysis was performed, and the effect of springback on fuel cell stack stresses was investigated.

Thinning and residual stresses of sheet metal in the deep drawing process

This paper presents a Finite Element (FE) model developed for the 3-D numerical simulation of sheet metal deep drawing process (Parametric Analysis) by using ABAQUS/EXPLICIT Finite Element Analysis (FEA) program with anisotropic material properties and simplified boundary conditions. The FE results are compared with experimental results for validation. The developed model can predict the thickness distribution, thinning, and the maximum residual stresses of the blank at different die design parameters, including both geometrical and physical parameters. Furthermore, it is used for predicting reliable, working parameters without expensive shop trials. Predictions of the thickness distribution, thinning and the maximum residual stresses of the sheet metal blank with different design parameters are reported. Frictional limitations and requirements at the different interfaces are also investigated.

Thinning and spring back prediction of sheet metal in the deep drawing process

The spring back simulation helps to get the required tolerance of the punch travel distance. This tolerance is needed in getting the required height of the final drawn part. Prediction of the forming results as spring back, determination of the thickness distribution and of the thinning of the sheet metal blank reduces the production cost of the material and time. In this paper, A Finite Element (FE) model is developed for the 3-D numerical simulation of sheet metal deep drawing process (Parametric Analysis) by using ABAQUS/EXPLICIT FEA program with the proper material properties (anisotropic material) and simplified boundary conditions. The FE results are compared with experimental results for validation. The developed model predicts the spring back, the thickness distribution and thinning of the blank as affected by the die design parameters (geometrical parameters and physical parameters). Furthermore, with numerical simulation, working parameters such as punch force, the blank holder force, and the lubrication requirements can be determined without expensive shop trials.