Theoretical Analysis of Plastic Forming Process for Semi-Solid Material

2005 ◽  
pp. 389-392
Author(s):  
Hong Yan ◽  
Juchen Xei
Keyword(s):  
Theoretical Analysis ◽  
Solid Material ◽  
Forming Process ◽  
Plastic Forming ◽  
Semi Solid

Theoretical Analysis of Plastic Forming Process for Semi-Solid Material

2005 ◽  
Vol 488-489 ◽  
pp. 389-392 ◽  
Author(s):  
Hong Yan ◽  
Juchen Xei
Keyword(s):  
Magnesium Alloy ◽  
Upper Bound ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Normal Component ◽  
Solid Material ◽  
Tangential Component ◽  
Forming Process ◽  
Plastic Forming ◽  
Semi Solid

The plastic forming of magnesium alloy is difficult, but the semi-solid material forming is a good method solved this problem. The mechanical model of the semi-solid materials was treated as that of the continuous porous materials in the high solid volume fraction. The upper bound theory applied for semi-solid metal plastic forming process was developed. The velocity discontinuities exist not only in the tangential component but also in normal component for the kinematically admissible displacement increment filed. The latter one was responsible for a change in solid volume fraction when the material passes the discontinuity. An upper bound analytical model and theoretical method of plastic forming process for semi-solid material has been proposed. The calculating formulas of deformed power were derived. It is theoretical basement to apply further for the practice technology analysis such as the plastic forming of magnesium alloy.

Theoretical Analysis of Laser Shock Bulging Forming

2012 ◽  
Vol 472-475 ◽  
pp. 2480-2483 ◽  
Author(s):  
Guo Fang Zhang ◽  
Zhong Ji ◽  
Jing Liu ◽  
Chao Zheng ◽  
Jian Hua Zhang
Keyword(s):  
High Pressure ◽  
Theoretical Analysis ◽  
Analytical Model ◽  
Pulse Energy ◽  
Shock Pressure ◽  
Laser Shock ◽  
Plastic Response ◽  
Forming Process ◽  
Laser Shock Forming ◽  
Plastic Forming

Laser shock forming (LSF) is a novel plastic forming process which utilizes high-pressure plasma to deform thin metals to 3D configurations. The plastic response of a circular plate in laser shock bulging forming was theoretically studied. A simplified shock pressure model was established and then an analytical model was proposed to calculate the deflection. The results show that the deflection increases with increasing pulse energy and the deformation profiles calculated by the analytical model agree well with those of experiment.

An Experimental Investigation on Semi-Solid Forming of Micro/Meso-Scale Features

2006 ◽  
Vol 129 (2) ◽  
pp. 246-251 ◽  
Author(s):  
Gap-Yong Kim ◽  
Jun Ni ◽  
Rhett Mayor ◽  
Heesool Kim
Keyword(s):  
Material Flow ◽  
Optical Measurement ◽  
Solid Material ◽  
Complex Interaction ◽  
Experimental Setup ◽  
Forming Process ◽  
Die Filling ◽  
Forming Technology ◽  
Semi Solid ◽  
Meso Scale

The potentials of semi-solid forming technology have generated much interest regarding its application in micromanufacturing. This study investigates the feasibility of using semi-solid forming technology to produce parts with micro/meso features. An experimental setup has been developed to study the effects of die/punch temperature, initial solid fraction, punch speed, and workpiece shape on the semi-solid forming process. A part has been produced for a microreactor application and has been analyzed with an optical measurement system for feature formation. The results indicated complex interaction among the process parameters and the material flow, which affected the final pin formation. The punch temperature and velocity had a significant effect on the overall die filling. The initial workpiece shape and solidification of the semi-solid material during forming influenced the micro/meso-feature formation sequence, affecting the final pin formation. Furthermore, grain deformation and distribution of the formed parts were investigated. The grains became larger due to induction heating and the forming process. Severely distorted grains were observed at the corner regions of the pins and the punch-workpiece interface.

Modeling of the Semi-Solid Material Behavior and Analysis of Micro-/Mesoscale Feature Forming

2006 ◽  
Vol 129 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Gap-Yong Kim ◽  
Muammer Koç ◽  
Rhet Mayor ◽  
Jun Ni
Keyword(s):  
Solid Fraction ◽  
A356 Alloy ◽  
Structural Evolution ◽  
Solid Material ◽  
Material Behavior ◽  
Flow Rule ◽  
Stress Model ◽  
Forming Process ◽  
Mesoscale Feature ◽  
Semi Solid

One of the major challenges in simulation of semi-solid forming is characterizing the complex behavior of a material that consists of both solid and liquid phases. In this study, a material model for an A356 alloy in a semi-solid state has been developed for high solid fractions (>0.6) and implemented into a finite element simulation tool to investigate the micro-/mesoscale feature formation during the forming process. Compared to previous stress models, which are limited to expressing the stress dependency on only the strain rate and the temperature (or the solid fraction), the proposed stress model adds the capability of describing the semi-solid material behavior in terms of strain and structural evolution. The proposed stress model was able to explain the strain-softening behavior of the semi-solid material. Furthermore, a simulation model that includes the yield function, the flow rule, and the stress model has been developed and utilized to investigate the effects of various process parameters, including analysis type (isothermal vs nonisothermal), punch velocity, initial solid fraction, and workpiece shape (“flat” versus “tall”) on the micro-/mesofeature formation process.

A Study on the Flow Behavior of 42CrMo Steel under Hot Compression by Thermal Physical Simulations

2010 ◽  
Vol 108-111 ◽  
pp. 494-499
Author(s):  
Ying Tong ◽  
Guo Zheng Quan ◽  
Gang Luo ◽  
Jie Zhou
Keyword(s):  
Strain Rate ◽  
Flow Behavior ◽  
Rate Sensitivity ◽  
Strain Hardening Exponent ◽  
Forming Process ◽  
Material Parameters ◽  
Basic Model ◽  
42Crmo Steel ◽  
Plastic Forming ◽  
Physical Simulations

This work was focused on the compressive deformation behavior of 42CrMo steel at temperatures from 1123K to 1348K and strain rates from 0.01s-1 to 10s-1 on a Gleeble-1500 thermo-simulation machine. The true stress-strain curves tested exhibit peak stresses at small strains, after them the flow stresses decrease monotonically until high strains, showing a dynamic flow softening. And the stress level decreases with increasing deformation temperature and decreasing strain rate. The values of strain hardening exponent n, and the strain rate sensitivity exponent m were calculated the method of multiple linear regression, the results show that the two material parameters are not constants, but changes with temperature and strain rate. Then the two variable material parameters were introduced into Fields-Backofen equation amended. Thus the constitutive mechanical discription of 42CrMo steel which can accurately describe the relationships among flow stress, temperature, strain rate, strain offers the basic model for plastic forming process simulation.

scholarly journals Plastic forming processes of transverse non-homogeneous composite metallic sheets

2021 ◽  
Vol 11 (1) ◽  
pp. 294-302
Author(s):  
Gal Davidi
Keyword(s):  
Inner Core ◽  
Plastic Material ◽  
Radial Solution ◽  
Algebraic Differential Equation ◽  
Forming Process ◽  
Perfectly Plastic ◽  
Plastic Forming ◽  
Validity Limit ◽  
Significant Achievement

Abstract In this work an analysis of the radial stress and velocity fields is performed according to the J 2 flow theory for a rigid/perfectly plastic material. The flow field is used to simulate the forming processes of sheets. The significant achievement of this paper is the generalization of the work by Nadai & Hill for homogenous material in the sense of its yield stress, to a material with general transverse non-homogeneity. In Addition, a special un-coupled form of the system of equations is obtained where the task of solving it reduces to the solution of a single non-linear algebraic differential equation for the shear stress. A semi-analytical solution is attained solving numerically this equation and the rest of the stresses term together with the velocity field is calculated analytically. As a case study a tri-layered symmetrical sheet is chosen for two configurations: soft inner core and hard coating, hard inner core and soft coating. The main practical outcome of this work is the derivation of the validity limit for radial solution by mapping the “state space” that encompasses all possible configurations of the forming process. This configuration mapping defines the “safe” range of configurations parameters in which flawless processes can be achieved. Several aspects are researched: the ratio of material's properties of two adjacent layers, the location of layers interface and friction coefficient with the walls of the dies.

Coupled Thermo-Mechanical FEA of Three-Roll Cross Rolling Process for Rings with Small-Hole and Deep Groove

2012 ◽  
Vol 560-561 ◽  
pp. 846-852 ◽  
Author(s):  
Qi Ma ◽  
Lin Hua ◽  
Dong Sheng Qian
Keyword(s):  
Rolling Process ◽  
Small Hole ◽  
Fe Model ◽  
Forming Process ◽  
Software Environment ◽  
Cross Rolling ◽  
Design And Optimization ◽  
Forming Technology ◽  
Deep Groove ◽  
Plastic Forming

Ring parts with small-hole and deep groove such as duplicate gear and double-side flange, are widely used in various engineering machineries. Three-roll cross rolling (TRCR) is a new advanced plastic forming technology for the processing of rings with small-hole and deep groove. In this paper, a 3D coupled thermo-mechanical FE model for TRCR of ring with small-hole and deep groove is established under ABAQUS software environment. By simulation and analysis, the evolution and distribution laws of strain and temperature in the forming process are revealed, and the effects of the key process parameters on the deformation uniformity are explored. The results provide valuable guideline for the technological parameter design and optimization.

scholarly journals Simulation of plastic forming process of shells with minimal thickness fluctuations

2017 ◽  
Vol 201 ◽  
pp. 489-494
Author(s):  
E.G. Demyanenko ◽  
I.P. Popov ◽  
A.N. Epifanov
Keyword(s):  
Forming Process ◽  
Minimal Thickness ◽  
Plastic Forming

Process Optimization for Suction Plastic Forming of In-Mold Decoration Plastic Sheet with CAE

2010 ◽  
Vol 102-104 ◽  
pp. 74-78
Author(s):  
Bin Gao ◽  
Xiu Rong Nan ◽  
Bai Zhong Wu
Keyword(s):  
Process Optimization ◽  
Thin Shell ◽  
Optimization Methods ◽  
Analysis Software ◽  
Optimization Scheme ◽  
Forming Process ◽  
Element Analysis ◽  
Plastic Sheet ◽  
Mesh Model ◽  
Plastic Forming

The suction plastic forming process for in-mold decoration plastic sheet has been the best process for thin-shell plastic exterior decoration parts. But the suction plastic forming products still suffers from the uneven thickness. Based on the general finite element analysis software POLYFLOW for viscoelastic fluid, a set of optimization methods for suction plastic forming process of in-mold decoration plastic sheet is introduced in this paper to reduce the uneven level of thickness. These methods include establishing process optimization scheme, building mesh model, selecting the material constitutive model and determining its parameters, imposing boundary conditions and blowing pressure, and applying the mold movement. Finally, the optimized suction plastic forming process is used to produce the in-mold decoration plastic rear bumper sample of an automobile, and the results show that optimized process is effective and applicable.

Study on Rheo-Diecasting for In Situ Synthesized Mg2Si/AM60 Composites

2011 ◽  
Vol 383-390 ◽  
pp. 707-711
Author(s):  
Hong Yan ◽  
Yong Hu ◽  
Xiao Quan Wu
Keyword(s):  
Die Casting ◽  
Casting Machine ◽  
Chinese Script ◽  
Matrix Composites ◽  
Forming Process ◽  
Magnesium Matrix ◽  
Magnesium Matrix Composites ◽  
Mechanical Stirring ◽  
Semi Solid

Magnesium alloys have high specific strength, specific stiffness, excellent thermal conductivity and casting properties, which have a great prospects development in the industry, However, its low plasticity and ductility limited its application. Magnesium matrix composites can effectively improve its performance. Magnesium alloy die-casting is the main forming process, the conventional high-pressure die-casting (HPDC) defects in multi-cavity type, easy to volume gas, non-heat-treated. Compared with HPDC, the rheo-diecasting (RDC) process has been greatly developed for near-net shape components. In this paper, Mg2Si /AM60 composites is fabricated by in-situ synthesis and semi-solid magnesium matrix composites which are rheoformed in the die-casting machine are prepared by mechanical stirring. The results indicate that the microstructure of composites is non-dendritic and Chinese script type Mg2Si are fine distributed. The fundamental morphology of microstructure by HPDC is dendrite and liquid-phase distributed between dendrite irregularly. The RDC samples have close-to-zero porosity, less segregation, the most of semi-solid of microstructure in rheo-diecasting is spherical or as-spherical structure.

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