DEFORM-3D Simulation Research Articles

Optimization of Thixoforging process parameters of A356 alloy using Taguchi’s experimental design and DEFORM Simulation

The present article investigates the application of Taguchi’s experimental design and emphasizes about the application of DEFORM 3D simulation to predict the material flow in the semi-solid stage and to optimize the thixoforging parameters of semi-solid A356 alloy. From the Taguchi analysis, the optimum level of thixoforging process parameters to obtain maximum hardness of semi-solid processed components of A356 aluminum alloy were found to be at a thixoforging temperature of 580°C, a solid fraction of 0.5; deformation of 40% and die temperature of 200° C. Further, from the DEFORM simulation analysis similar optimal thixoforging process factors were also obtained as: deformation of 40% at a forging temperature of 580°C which corresponds to a solid fraction (fs = 0.5). Thus, the DEFORM 3D results showed how effective is the computer simulation in reducing the costly trial and errors and saving time.

Estimation of shear force for blind shear ram blowout preventers

In this study, the estimation of shear force for blind shear ram type blowout preventer was investigated by using Finite Element Method (FEM). So, the effect of the blowout preventer working condition on shear force requirement for shear operation could be accurately approximated by simulating the entire process, and ram geometry could be optimized to reduce force and energy used to shear the tube by plastic deformation. The results of FEM analyzes was compared with blowout preventer manufacturer shear force information. Comparisons show that forces evaluated by using FEM (Deform 3D) simulations provided fairly accurate results for actual shear force. Also, it was found that by using Finite Element simulations the effect of the blowout preventer working condition on shearing operation can be estimated and ram geometries can be optimized. Therefore, FEM analyses could be used to design more reliable and efficient ram type blowout preventers.

Study on impacting mechanism in grinding process based on DEFORM simulation and experiment

Grains have the impacting effect to the surface materials in grinding. In order to study the impact in the grinding process, the paper carried on the simulation by using DEFORM-3D software and conducted the grinding hardening experiment. It simulated the impact to the surface materials which was functioned by single grain and got the distribution of stress field of internal workpiece, analysed the equivalent stress and strain rate of surface of workpiece in the grinding process. It shows the analysis of equivalent stress reflected that grinding force is made up of a lot of surging force. The analysis of strain rate indicated that the impact and hardening effect to the surface of workpiece by grains is remarkable existing. The results of the experiment verified the correctness of simulation. DEFORM-3D simulation method could analyse and predict the parameter of surface hardened layer effectively.

Research on the Heat Processing Theory and Damage of Martensitic Stainless Steel

Through the Gleeble-1500D thermal simulator, the paper were carried out hot compression and tensile experiments on the 1Cr13 martensitic stainless steel, and get the different deformation curve under the conditions of stress strain. At the same time, we get the constitutive equations and Z parameters, which provide necessary material model for numerical simulation of the stainless steel forging process. The compression and tensile tests were simulated with DEFORM-3D simulation software, respectively; get the material value of the fracture damage ductile fracture critical damage and material void initiation damage, it will reasonable provide reference in production process and prevention crack in the process of forging.

Simulation on Flexible Thixo-Extrusion of Variable Cross-Section Part Based on DEFORM-3D Software

Flexible thixo-extrusion, as an innovative near-net-shape forming method, has huge advantages in processing the components with complex geometry. However, it should keep in mind that conventional liquid casting still represents the dominant mean of aluminum alloys production. One of the obstacles the thixo-extrusion has to overcome is lack of proof that can live up to the claim that thixo-extruded components have better mechanical properties. The main aim of this paper is to simulate the flexible thixo-extrusion process of aluminum alloy A356 and investigate the control method of materials flow front. An isothermal compression test of aluminum alloy A356 is first conducted to obtain the true stress-strain curves at different temperatures and strain rates. A constitutive equation describing the relationship of stress, strain, strain rate and temperature is fitted by Origin and then imported to the DEFORM-3D simulation software. The results show that the quality of final component is enormously influenced by the radius of the arcs and the flexible thixo-extruded components has less defects compared with the conventional extruded ones.

3D finite element modelling and experimental researches on turning steel AISI1013 by nano-crystalline Al<SUB align="right">2O<SUB align="right">3 ceramics cutter

Tool wear is an important problem in turning of alloys by tool especially for nano-crystalline Al2O3 ceramics cutter. Coupled thermo mechanical finite element modelling of 3D metal turning of alloy steel AISI1013 by nano-crystalline ceramics tool have been investigated by utilising DEFORM-3D simulations. Conditions of initial and boundary and turning process parameters have been applied in simulation process. The highest temperature rises of tool tip are below the temperature of dynamic recrystallisation, so the nano-Al2O3 ceramics tool has better thermal stability. The reasons of force dropping and total wear increasing are the temperature rise in the tool tip, bigger turning forces could improve the wear rates. Through these researches more turning parameters can be estimated and it could be helpful to predict the variation of cutting force, cutting tool wears and temperature evolutions. The obtained results provide the fundamental and practical guidelines for the metal turning by nano-crystalline ceramics tool.

A new methodology for prediction of fracture initiation in hot compression of Ti40 titanium alloy

It is well known that once plastic deformation reaches a certain limit, metal materials may undergo ductile fracture, which will affect the workability of engineering materials. The accurate prediction of a material ductile fracture is thus of practical importance in the optimization of processes and improvement of products. The knowledge of the strain paths at a critical fracture site of a deforming material is helpful to study the detailed mechanics in the workability. Therefore, an accurate determination of the critical fracture reduction is a prime requirement for proper design and control of any metalworking process. However, it is always a difficult problem on a hot deformation field. In this work, a new high-speed photography was proposed for capturing the initiation and propagation of ductile fracture of Ti40 alloy during hot compression. The results suggest that the high-speed photography technology can clearly display the nucleation site and propagation process of cracking, and thus is an excellent method to represent dynamically the hot-deformation fracture. Based on the Oh fracture criterion, a new hot-deformation fracture criterion, which considered the effect of temperature and strain rate, was built. Then, by combining the DEFORM-3D simulation software and FROTRAN language, hot workability of Ti40 titanium alloy in metalworking processes can be predicted which shows that the proposed prediction model can precisely predict the fracture initiation in the upsetting of Ti40 ingot. Even better, this model can be further applied for optimizing the canned upsetting and indicates that the canned forging is effective for avoiding the oxidation cracking.

Influence of Material Flow Stress on Surface Roughness in High-Speed Machining

A mechanical model of surface roughness is established based on the Kragelskii-Drujanov theory of friction and wear and Hertz elastic contact theory. Effect of material flow stress on remnant height of the machined surface was investigated. Test showed that the machined surface morphology provides the phenomena of the side flow in the vertical direction of ploughing in high-speed machining. The remnant height values on the machined surface of the high-speed machining are obtained by DEFORM-3D simulation. Based on the results it can be concluded that the surface roughness values of the workpiece increase with material flow stress.

Simulation of Compound Cold Extrusion Al-Zn-Mg-Cu Alumium Alloys

Al-Zn-Mg-Cu super-high strength aluminum alloy is widely used in the aerospace and automotive industry. However, the extrudability of Al-Zn-Mg-Cu aluminum alloy is relatively poor compared with other series of aluminum alloys. The simulation of compound cold extrusion process of Al-Zn-Mg-Cu aluminum alloy was studied for the production of a double-cup workpiece with a deep wobbler hole in this paper. The effective strain and stress distribution of the alloy during cold extrusion were studied by Deform-3D simulation. The results show that the maximum stress was concentrated at the bottom of the deep hole. Cracks were easily to be occured near the bottom of deep-hole. Based on the experimental results, the processing route of the two steps with compound cold extrusion is more suitable than one cold extrusion for the production.

Finite Element Simulation of Steel Quench Distortion- Parametric Analysis of Processing Variables

ABSTRACTSteel quenching from the austenite region is a widely used industrial process to increase strength and hardness through the martensitic transformation. It is well known, however, that it is very likely that macroscopic distortion occurs during the quenching process. This distortion is caused by the rapidly varying internal stress fields, which may change sign between tension and compression several times during quenching. If the maximum internal stress is greater than the yield stress at given processing temperature, plastic deformation will occur and, depending on its magnitude, macroscopic distortion may become apparent.The complex interaction between thermal contraction and the expansion resulting from the martensitic transformation is behind the sign changes in the internal stress fields. Variations in the steel composition and cooling rate will result in a number of different paths, which the internal stresses will follow during processing. Depending on the route followed, the martensitic transformation may hinder the thermal stresses evolution to the point where the stress fields throughout the component may actually be reverted. A different path may support the thermal stresses evolution further increasing their magnitude. The cross-sectional area also affects the internal stresses magnitude, since smaller areas will have further trouble to accommodate stress, thus increasing the distortion. Additionally, the bainitic transformation occurring during relatively slow cooling rates may have an important effect in the final stress field state.A finite-element (FE) model of steel quenching has been developed in the DEFORM 3D simulation environment. This model has taken into account the kinetics of both austenite-bainite and austenite-martensite transformations in a simplified leaf spring geometry. The results are discussed in terms of the optimal processing parameters obtained by the simulation against the limitations in current industrial practice.

Stress Analysis of Cold Die Compaction with Rotating Tools for Aluminum Powder

In this paper, a modified slab analysis has been used to determine the pressure distribution in the cylindrical compaction of aluminum powder under rotating die compaction. The analytical results are discussed to explain the pressure distribution and the interaction of the various parameters. To predict the density distribution in a powder compact under an applied pressure with torsion, the pressure function is coupled with some form of a pressure density relationship. High relative density can be realized in powder compacts by the rotating die compaction in contrast to the conventional compaction. A numerical analysis, using the DEFORM3D simulation software, is also carried out on the compaction under the rotating punch.

Application of computer aided simulation to investigate metal flow in selected forging operations

The application of computer aided engineering (CAE) techniques continues to increase in metal forming research and development. The two dimensional computer code DEFORM is now extensively used in forging applications for the investigation of die fill, defect analysis and prevention, as well as prediction of part properties. The three dimensional version of DEFORM has recently been released. At the Engineering Research Center for Net Shape Manufacturing (ERC/NSM), DEFORM is one of the available computer aided tools used in cold-, warm- and hot-forging research and for educational purposes. This paper summarizes the results of industrially relevant “work-in-progress” research with the DEFORM and DEFORM-3D FEM systems. Current projects include: a new tool design for cross groove inner race for a constant velocity joint, the flashless forging of an aluminum connecting rod, design of cold forgings and forming sequences, die wear in warm forging extrusion, and examples of DEFORM-3D simulations of a connecting rod, blade coining, and wire drawing of shapes.