Simulation of Thixocasting Processes in Automotive Component

2005 ◽  
Vol 480-481 ◽  
pp. 361-366
Author(s):  
Antonio Forn ◽  
Sergi Menargues ◽  
Enric Martín ◽  
G.L. Chiarmetta

Thixocasting or semi-solid casting is an alternative to the traditional casting processes. A numerical simulation of these methods is useful to define the real process. A new test concept will be presented to determine parameters, such as temperature and rates, as well as the die filling and solidification processes. The simulation tools permit us to understand better the processes, to predict and to eliminate potential defects before they take place. The studied component is a steering knuckle made of an A357 aluminium alloy. The microstructure is characterized by optical microscopy. It has been preceded to the development of a model based on the experimental data, it has been defined to the semi-solid as an homogeneous material with thixotropic properties, and the microstructure is a structural parameter. The results are compared with real tests.

2011 ◽  
Vol 704-705 ◽  
pp. 82-87
Author(s):  
Lei Rao ◽  
Lian Bing Zhu ◽  
Xiao Long Li ◽  
Qi Yao Hu

Brake hydro cylinder is the key part of automobile hydraulic braking system, which usually works under high pressure condition. So, high safety factor of it is required to avoid accident. There are many kinds of casting defects such as shrinkage cavity, gas entrapment and slag enclosure are formed in the mold filling and solidification processes, which contribute to final casting performance. Based on the mathematical models of molding filling and solidification processes, the numerical simulation has been done. In the meanwhile, the defects forming reasons have been analyzed. According to the simulation results, two types of improved schemes have been analyzed and practiced respectively, and its work piece defects were reduced largely. It is an effective way to improve the casting quality by advanced computer technology.


2011 ◽  
Vol 399-401 ◽  
pp. 13-16
Author(s):  
Jian Min Zeng ◽  
Jie Liang ◽  
Zhi Liu Hu ◽  
Ping Chen ◽  
Li Hua Liang

Simulation software is an essential tool for today‘s engineers. Its application enables castings to be designed with predicting the final results prior to they are produced. Thus, the simulation plays significant role in casting production. If a realistic calculation of the mold filling and solidification processes can be made it is possible to predict casting defects caused by casting system and/or casting design. In order to understand the changes occurring during solidification of casting, numerical simulation has been used in our classroom teachings for postgraduates. The software structures, mathematical principles, software utility, functions and output criteria are introduced in this paper to demonstrate that computer aided instruction is of Intuitive, attractive and can be used in classroom before the real experiments as assistant means to help postgraduates to understand what is casting and what is solidification


2011 ◽  
Vol 52-54 ◽  
pp. 1532-1537
Author(s):  
Shu Zhen Shang ◽  
Gui Min Lu ◽  
Xiao Ling Tang ◽  
Zu Xin Zhao ◽  
Wei Cao

Effects of deformation temperature and strain rate on deformation behavior of semi-solid 6061 alloy were investigated on Gleeble3800 thermal-mechanical simulator. On basis of the experimental data of semi-solid 6061, a model was established to describe the relationship between the processing parameters and flow stress, which showed that the experimental results and calculation ones fitted well. It would be beneficial to realize the distribution of stress and strain during the semi-solid forming on the basis of numerical simulation technology. This research paper presented the numerical simulation results of the 6061 alloy during the backward extrusion thixoforming process.


2011 ◽  
Vol 474-476 ◽  
pp. 255-259 ◽  
Author(s):  
Ya Ping Hu ◽  
Yong Hu

Numerical simulation can be used to predict die filling, and hence to optimize the die design. In the study, the flow characteristics of liquid filling comparing with those of semi-solid filling were analyzed. The results indicated that the liquid filling turned out to be turbulent, while the semi-sold filling had laminar flow characteristics which could reduce the foundry defects such as gas cavity and oxidation mixture. The distribution of pressure reduced gradually in the filling direction during semi-solid filling process which would generate back pressure that was favorable for filling process.


2008 ◽  
Vol 141-143 ◽  
pp. 325-330
Author(s):  
Krzysztof P. Sołek ◽  
Zbigniew Mitura ◽  
Mirosław Karbowniczek ◽  
Plato Kapranos ◽  
Roman Kuziak ◽  
...  

The main goal of this work is the analysis of rheological properties of steel alloy at high temperatures, just below the solidus point, and in the semi-solid state with low liquid phase content. Data obtained from the analysis can form the basis of numerical simulation for designing and optimizing the thixoforming processes. The rheological properties should be known over a wide temperature range so that the simulations could also predict defects such as incomplete die filling. The analysis concerned M2 tool steel alloy. The paper also discusses development of globular microstructure in partially melted steel.


2009 ◽  
Vol 16-19 ◽  
pp. 535-539
Author(s):  
Deng Yu Gai ◽  
Yu Zhao Chu ◽  
Qing Fen Li ◽  
Qun Xia Li

3-D velocity and temperature fields of mold filling and solidification processes of large turbine blade casting were simulated. It indicated that the velocity field of upright casting is faster and steadier than lying casting. The deformation was predicted and the rule of deformation was reflected by analyzing stress field during solidification of upright casting. The casting processes were optimized, and then applied to produce castings.


2013 ◽  
Vol 791-793 ◽  
pp. 550-553 ◽  
Author(s):  
Dong Dong Han ◽  
Cheng Jun Wang ◽  
Juan Chang ◽  
Lei Chen ◽  
Huai Bei Xie

At present, pulley produced in China has been able to meet the demand of domestic and international markets. But there are many problem of the pulley industry in our country, such as too many production enterprises and the low level of export products. And as components of drive system are light weight and raw material price of pulley casting are rising, manufacturing requirements of the pulley are also more and more high. Aiming at the casting defects of pulley that enterprise current product, pulley casting blank model of common material HT250 be made by three-dimension software, numerical simulation of filling and solidification process for pulley sand casting by the casting simulation software Procast, the size and location of the various casting defects were forecasted and analyzed, reflecting the pulley filling and solidification process of the actual situation, due to the thicker pulley rim and less heat dissipation, position of shrinkage is close to the middle of rim [, a method of eliminating defects is proposed to realize sequential solidification, and thus to minimize porosity shrinkage and improve casting performance and reduce casting time and reduce production costs.


2008 ◽  
Vol 602 ◽  
pp. 209-218 ◽  
Author(s):  
J. J. J. GILLISSEN ◽  
B. J. BOERSMA ◽  
P. H. MORTENSEN ◽  
H. I. ANDERSSON

We use direct numerical simulation to study turbulent drag reduction by rigid polymer additives, referred to as fibres. The simulations agree with experimental data from the literature in terms of friction factor dependence on Reynolds number and fibre concentration. An expression for drag reduction is derived by adopting the concept of the elastic layer.


2019 ◽  
Vol 3 (3) ◽  
pp. 73 ◽  
Author(s):  
Mohamad Karaki ◽  
Rafic Younes ◽  
Francois Trochu ◽  
Pascal Lafon

A great amount of attention has been given to the evaluation of the permeability tensor and several methods have been implemented for this purpose: experimental methods, as well as numerical and analytical methods. Numerical simulation tools are being seriously developed to cover the evaluation of permeability. However, the results are still far from matching reality. On the other hand, many problems still intervene in the experimental measurement of permeability, since it depends on several parameters including personal performance, preparation of specimens, equipment accuracy, and measurement techniques. Errors encountered in these parameters may explain why inconsistent measurements are obtained which result in unreliable experimental evaluation of permeability. However, good progress was done in the second international Benchmark, wherein a method to measure the in-plane permeability was agreed on by 12 institutes and universities. Critical researchers’ work was done in the field of analytical methods, and thus different empirical and analytical models have emerged, but most of those models need to be improved. Some of which are based on Cozeny-Karman equation. Others depend on numerical simulation or experiment to predict the macroscopic permeability. Also, the modeling of permeability of unidirectional fiber beds have taken the greater load of concern, whereas that of fiber bundle permeability prediction remain limited. This paper presents a review on available methods for evaluating unidirectional fiber bundles and engineering fabric permeability. The progress of each method is shown in order to clear things up.


2013 ◽  
Vol 419 ◽  
pp. 355-359
Author(s):  
Lei Wang ◽  
Wei Li Liu ◽  
Le Sheng Chen

The paper analyzes the influence of structural parameters on the electrical performance of the microstructured environmentally-friendly electrical contact material Ag/SnO2 by using numerical simulation method.The numerical results show that the reisitivity of fiber-like electrical contact material Ag/SnO2 is significantly reduced compared with the resistivity of Ag/SnO2 adding reinforcing nanoparticles in the traditional way.So the fiber-like electrical contact material Ag/SnO2 exhibits higher conductivity in macro. On further analysis, we learn that the resistivity of fibrous electrical contact materials is related to weight percent of reinforced phase, and micro-structural parameter of length to diameter ratio. The resistivity increases as weight percent of reinforced phase increases,and decreases non-linearly with micro-structural parameter of length to diameter ratio increasing.This demonstrates that numerical simulation is one of effective methods for analysis of the electrical performance of the microstructured electrical contact material.


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