An Analysis of Three Different Dies Profile for Cold Extrusion Process

Transcription

1 An Analysis of Three Different Dies Profile for Cold Extrusion Process ShubhamShrivastava 1, Prof K.K. Jain 2 1 Research scholar, Department of mechanical Engg SRIT, Jabalpur, (M.P) 2 Prof., Department of Mechanical Engg SRIT, Jabalpur, (M.P) Abstract- In the present work, three different die shapes have been considered i.e. Third-order polynomial die, Cosine die and Conical die. AL 1100-O is used as the filler material for all the three dies. The material to be extruded was modelled as a perfect plastic material for the non-linear analysis during the finite element simulation. Output from the finite element program included Directional deformation, at different Die Pressure i.e. 800 MPa, 1200 MPa and 1600 MPa. Based on the finite element analysis results the Cosine die is best among all the three-die considered for the study i.e. Cosine Die, Third-order polynomial Die and conical die. Index Terms- Extrusion, die design, die shapes, Cosine Die, Third-order polynomial Die and conical die. I. INTRODUCTION 1.1General Metal forming is the process of plastically deforming the raw material into productform. It is broadly classified into two classes bulk metal forming and sheet metalforming. In the bulk metal forming processes, usually the workpiece has a highvolume to surface area ratio. Examples of such processes are rolling, wiredrawing, extrusion, forging etc. In the sheet metal forming processes, usually thework-piece sheet has a low volume to surface area ratio. The sheets usually have athickness less than 6 mm. In sheet metal working, the change in thickness duringplastic deformation is not desirable. Examples of sheet metal forming processes aredeep drawing, stretch forming, bending, spinning etc. Figure 1.1 shows the most important metal forming processes. 1.2 Extrusion In extrusion processes, the metal in the form of a cast billet is shaped by pressing it through a die orifice of appropriate shape. When this is done, the metal flowsout of the orifice in a continuous manner and appears as a long profile, with cross-sectionalshape approximately the same as that of the die orifice. In extrusion themetal must first be placed inside the container, where it is pressurized. As depictedin Figure 1.2, this is done by placing a die at one end of the container, and a punchor a ram at the other end of it. Cast extrusion metal is inserted into the container as a billet. When the punchadvances, the metal of the billet fills the container and is pressed against thedie. With further advance of the ram, the metal starts to flow through the containerand out through the die as a profile, with the same cross section as the dieorifice. II-LITERATURE REVIEW Extrusion processes are quite extended in the manufacturing of long products for a wide range of industrial applications.there are different approaches of extrusion processes, depending on either the final shape of the product to obtain or themaximum loading capacity of the equipment to be used. 1.J. Xu, T. Yang, B. Jiang, J. Song, J. He, Q. Wang, Y. Chai, G. Huang, F. Pan, Improved mechanical properties of Mg-3Al-1Zn alloy sheets by optimizing the extrusion die angles: Microstructural and texture evolution, Journal of Alloys and Compounds (2018), doi: /j.jallcom Mg-3Al-1Zn (AZ31) alloy sheets fabricated using extrusion dies withangles of 30, 45, 60 and 90 were investigated. Finite element method was used toanalyze the effective strain distribution in AZ31 Mg alloy during extrusion IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 33

2 by Jun Xu et al; The microstructure, texture and final mechanical properties were determined andcompared among various extruded AZ31 sheets. Results demonstrated that thedifference of effective strain was introduced during extrusion due to the variation indie angles. 2.A. García-Domínguez, J. Claver, A.M. Camacho, M.A. Sebastián; 2015, Comparative Analysis of Extrusion Processes by Finite Element Analysis, Procedia Engineering 100 (2015) A. García-Domínguez et al; 2015 presented a comparative study of extrusion processes (solidand cup extrusion), considering both direct and indirect forming conditions and showing the most interesting differences betweenthem. The comparison is realized by Finite Element simulation of the processes, using the code DEFORM F2. The material is alow carbon steel (AISI-1010) and the same extrusion ratio and ram displacement are considered in all cases. By comparing therequired forces it can be concluded that required loads are higher in cup extrusion processes than in solid extrusion ones. 3.Ding Tang, Wenli Fang, Xiaohui Fan, Dayong Li, YinghongPeng; 2014, Effect of die design in micro-channel tube extrusion, 11th International Conference on Technology of Plasticity, ICTP 2014, October 2014, Nagoya Congress Center, Nagoya, Japan Micro-channel tube (also called Multi-port extrusion tube) with sub-millimeter-diameter ports in the cross-section is a newlydeveloped type of aluminum extrusion with the basis for its design in micro-scale heat transfer theory. Comparing to traditionalheat exchanger tube with channel diameter more than 2 mm, microchannel tube has great advantage on high heat transferefficient, light weight, high bearing capacity.. III-RESEARCH METHODOLOGY In the present work for analysis, Finite Difference Method is considered. In this method a small volume of the material undergoing deformation is considered.as this element is an integral part of the material, it is always be in state of equilibrium. This results in one or more differential equations which together with necessary boundary conditions, yields the deformation load. A mechanical simulation of the extrusion process was performed using the finite element software (ANSYS). This was achieved by constructing an accurate two-dimensional CAD model of the process. The model was meshed with appropriate elements and material properties and boundary conditions were added. 3.1 FEA Analysis Various theories and methods of analysis have been developed for analyzing problems in conventional metal extrusion process; can t be applied to the deformation of porous metals. In conventional wrought material extrusion analysis, volumetric constancy is assumed for the material undergoing deformation but this assumption can t be made in the plastic deformation of porous metals where density does not remain constant and changes with deformation. Yielding of porous metals is also not completely intensive to the hydrostatic stress imposed. Due to which, various methods are used for analysis of extrusion of porous metals i.e. Equilibrium or slab method, Finite difference method, Slip line method upper bound method, Uniform deformation energy method, Computerized analytical method, etc. 3.2 Modelling of Extrusion Process using Explicit Dynamics ELFEN/explicit, a dynamic explicit finite element code was used to perform the simulation. The flow formulation ANSYS provides an interface to the LS-DYNA explicit dynamics finite element program. The explicit method of solution used by LS-DYNA provides fast solutions for large deformation dynamics and complex contact problems. Using this interface, model can be structured in ANSYS, obtain the explicit dynamics solution via LS- DYNA, and review results using the standard ANSYS post processing tools. The procedure for an explicit dynamics analysis consists of three main steps: IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 34

3 1. Building the model. 2. Applying the loads and obtain the solution. 3. Review the results 3.3Part Design (Geometry) Autodesk Inventor is a 3-dimensional modeling package that allows the user to select a wide range of options in order to create and design mechanically sound and competent models. Figure 3.4, 3.5 and 3.6 shows the imported geometry of Conical, Cosine and Third-order polynomial die in ANSYS workbench. Figure 3.1 Conical Die geometry consider for the analysis Figure 3.2 Cosine Die consider for the analysis Figure 3.5 (a, b and c) Meshing of Present Model (die and punch) Boundary Conditions (Assumptions) The simulations performed in this study make the following assumptions: (1) The container, ram, and the die are rigid bodies; (2) The extrusion billet is a rigid-plastic material; (3) The friction factor (μ) between the extrusion billet and the ram is equal to that between the extrusion billet and the die; and (4) The effects of the deformation-induced temperature rise are neglected. IV-RESULTS AND ANALYSIS Figure 3.3Third-order polynomial Die consider for the analysis 3.2.5Material Definitions AL 1100-O is used as the filler material for all the three dies. Table 3.1 shows the property of the material Meshing (Discretization) The quadrilateral mesh was chosen. Compaction was applied at inward portion of the circular portion of the die with the help of punch. The total numbers of nodes are31739 along with elements. A finite element analysis (FEA) of the cold extrusion process was undertaken.the FEAsimulation was carried out using ANSYS, EXPLICIT DYNAMICS tool, specifically produced for metal forming simulation. The following observations are carried out after the simulation process. The material to be extruded was modelled as a perfect plastic material for the non-linear analysis during the finite element simulation. Output from the finite element program included Directional deformation, Maximum Principal and Normal Elastic Strain, shear stress and equivalent stress at different Die Pressure i.e. 800 MPa, 1200 MPa and 1600 MPa. 4.2 Results for Conical Die IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 35

4 conical die at different die Results for Conical Die at 800 MPa die Figure 4.1 Directional Deformation along the length for Conical Die at 800 MPa die Results for Conical Die at 1200 MPa die Figure 4.5 Directional Deformation along the length for Cosine Die at 1200 MPa die Results for Cosine Die at 1600 MPa die Figure 4.2 Directional Deformation along the length for Conical Die at 1200 MPa die Results for Conical Die at 1600 MPa die Figure 4.6 Directional Deformation along the length for Cosine Die at 1600 MPa die 4.4 Results for Third-order polynomial Die Third-order polynomial die at different die Results for Third-order polynomial Die at 800 MPa die Figure 4.3 Directional Deformation along the length for Conical Die at 1600 MPa die 4.3 Results for Cosine Die cosine die at different die Results for Cosine Die at 800 MPa die Figure 4.7 Directional Deformation along the length for Third-order polynomial Die at 800 MPa die Results for Third-order polynomial Die at 1200 MPa die Figure 4.4 Directional Deformation along the length for Cosine Die at 800 MPa die Results for Cosine Die at 1200 MPa die Figure 4.8 Directional Deformation along the length for Third-order polynomial Die at 1200 MPa die Results for Third-order polynomial Die at 1600 MPa die IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 36

5 Figure 4.9 Directional Deformation along the length for Third-order polynomial Die at 1600 MPa die V-CONCLUSION A finite element analysis (FEA) of the cold extrusion process was undertaken.the FEA simulation was carried out using ANSYS,EXPLICIT DYNMICS tool, specifically produced for metal forming simulation. The following observations are carried out after the simulation process. It has been observed that at the particular value of die the conical die punch has less displacement as compare to other two. As the basis on displacement achieved the die which shows the high punch displacement for lower applied load/ is best suitable for the operation. With lower value of Die Pressure i.e. at initial stage for applying load there is generation of shearing is more as compared to lower values, if the cosine die is used. International Journal of Mechanical Sciences 44 (2002) [5] Guo-Bao Jin, Min-Jie Wang, Dan-Yang Zhao, Hui-Qing Tian, Yi-Fei Jin; 2014, Design and experiments of extrusion die for polypropylene five-lumen micro tube, Journal of Materials Processing Technology 214 (2014) [6] L. Pauli, M. Behr, S. Elgeti; 2013, Towards shape optimization of profile extrusion dies with respect to homogeneous die swell, Journal of Non-Newtonian Fluid Mechanics (2013) [7] N.H. Kim, C.G. Kang, B.M. Kim; 2001; Die design optimization for axisymmetric hot extrusion of metal matrix composites, International Journal of Mechanical Sciences 43 (2001) 1507}1520 [8] N.D. Gonçalves, O.S. Carneiro, J.M. Nóbrega; 2013, Design of complex profile extrusion dies through numerical modeling, Journal of Non- Newtonian Fluid Mechanics 200 (2013) REFERENCES [1] García-Domínguez, J. Claver, A.M. Camacho, M.A. Sebastián; 2015, Comparative Analysis of Extrusion Processes by Finite Element Analysis, Procedia Engineering 100 (2015) [2] Ding Tang, Wenli Fang, Xiaohui Fan, Dayong Li, YinghongPeng; 2014, Effect of die design in micro-channel tube extrusion, 11th International Conference on Technology of Plasticity, ICTP 2014, October 2014, Nagoya Congress Center, Nagoya, Japan [3] F. Gagliardi, G. Ambrogio, L. Filice; 2012, On the die design in AA6082 porthole extrusion, CIRP Annals - Manufacturing Technology 61 (2012) [4] Geun-An Lee, Yong-TaekIm; 2002, Analysis and die design of flat-die hot extrusion process and Numerical design of bearing lengths, IJIRT INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 37