scholarly journals Numerical Simulation of Reoxidation Processes

2020 ◽  
Vol 328 ◽  
pp. 02007
Author(s):  
Marek Bruna ◽  
Marek Galčík
Keyword(s):  
Numerical Simulation ◽  
Liquid Metal ◽  
Aluminium Alloy ◽  
Oxide Layer ◽  
Negative Impact ◽  
Casting Process ◽  
Simulation Software ◽  
Gating System ◽  
Alloy Casting ◽  
Positive Effect

Reoxidation is one of the main problem accompanying the aluminium alloy casting process. The oxide layer created on the melt surface during reoxidation is entrained into the bulk of liquid metal and “bifilms” are created. Bifilms have negative impact on cast quality and internal homogenity of final casting. Paper aim is to clarify the reoxidation phenomenon by visualization with the aid of ProCAST numerical simulation software. Experiemtnal work deals with the design of several types of gating systems (non pressurized and naturally pressurized) with vortex elements in order to determine how these elements affect the reoxidation processes. Achieved results clearly confirmed the positive effect of the naturally pressurized gating system with vortex elements. The evaluation focuses mainly on melt velocity and amount of oxides created in gating system and in mold cavity.

Application of Numerical Simulation on Cast-Iron Pneumatic Hammer Housing

2011 ◽  
Vol 474-476 ◽  
pp. 432-435
Author(s):  
Guo Fa Mi ◽  
Li Lin Chen ◽  
Bao Zhong Liu ◽  
Hai Yan Wang
Keyword(s):  
Numerical Simulation ◽  
Cast Iron ◽  
Solidification Process ◽  
Casting Process ◽  
Simulation Software ◽  
Gating System ◽  
Pneumatic Hammer ◽  
Shrinkage Defects ◽  
Simulation Results ◽  
D Model

The Pro/E software was used to generate 3-D model of pneumatic hammer housing casting. The solidification process of the casting was simulated by the numerical simulation software, View Cast. The location and scale of the shrinkage defects were shown in the results. The risers were designed by the View Cast software based on the simulation results. The reasonable risers were obtained after the optimization on the numerical simulation. And the parameters of gating system were got according to the simulation results calculated by the gating system designing function of View Cast. Then the solidification results demonstrated that the risers and pouring system could be planned by View Cast effectually. The reasonable casting process was obtained and the process has been proofed by the productive practice.

Numerical Simulation of Centrifugal Casting Process of Large Thin-Wall Ti Alloy Casting

2016 ◽  
Vol 850 ◽  
pp. 469-481
Author(s):  
Heng Shao ◽  
Yan Li ◽  
Peng Zhao ◽  
Hai Nan ◽  
Qing Yan Xu
Keyword(s):  
Numerical Simulation ◽  
Liquid Metal ◽  
Centrifugal Casting ◽  
Casting Process ◽  
Wall Structure ◽  
Thin Wall ◽  
Ti Alloy ◽  
Gravity Casting ◽  
Alloy Casting ◽  
Shrinkage Defects

Centrifugal pouring is often used in investment casting of large thin-wall Ti castings to promote filling. Shrinkage defects often appear in a Ti casting produced by centrifugal casting. Numerical simulation indicate that shrinkage is caused by these reasons: improper pouring system and thin-wall structure limited feeding of liquid metal from pouring system, and centrifugal force enlarged the shrinkage defects by strengthen feeding of liquid within the casting. Thus centrifugal casting is replaced by gravity casting and a new pouring system is adopted. Obvious shrinkage defects disappear in the new casting process.

Understanding the occurrence of the surface turbulence in a nonpressurized bottom gating system: Numerical simulation of the melt flow pattern

2015 ◽  
Vol 232 (3) ◽  
pp. 230-241 ◽  
Author(s):  
Ali Kheirabi ◽  
Amir Baghani ◽  
Ahmad Bahmani ◽  
Morteza Tamizifar ◽  
Parviz Davami ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Liquid Metal ◽  
Flow Pattern ◽  
Oxide Films ◽  
Critical Value ◽  
Surface Velocity ◽  
Complete Agreement ◽  
Gating System ◽  
Melt Flow ◽  
Surface Turbulence

Surface turbulence during the filling of the mold triggers the entrainment of oxide films, which appears to be detrimental to the soundness of the final casting. Nonpressurized and bottom-gating systems have been employed in order to avoid such casting defects by reducing the surface velocity of the liquid metal. However, recent studies have shown that the melt front velocity in the mold entrance may exceed the critical value in the nonpressurized and bottom-gating systems. Therefore, a study was conducted on numerical simulation melt flow pattern in nonpressurized and bottom-gating systems. It was noted that the liquid metal enters the gate and then mold cavity with a higher velocity by formation of dead zones and vortex flows in runner's end. Therefore, the current designs based on conventional gating system ratio seem to be not optimized and unable to avoid the surface turbulence. Numerical results were in complete agreement with experimental observations. Understanding the reasons for occurrence of the surface turbulence in nonpressurized and bottom-gating systems provides information on the required steps to improve the design of the gating systems and minimize the entrainment of oxide films during the filling of the mold.

Numerical Simulation on the Liquid Metal Flow of the Acceleration Phase in the Shot Sleeve of Cold Chamber Die Casting Process

2007 ◽  
Vol 561-565 ◽  
pp. 1801-1804
Author(s):  
Jie Yang ◽  
Lang Yuan ◽  
Shou Mei Xiong ◽  
Bai Cheng Liu
Keyword(s):  
Numerical Simulation ◽  
Liquid Metal ◽  
Metal Flow ◽  
Three Dimensional ◽  
Great Influence ◽  
Casting Process ◽  
Shot Sleeve ◽  
Three Dimensional Model ◽  
Acceleration Phase ◽  
Fill Ratio

Slow shot velocity and its acceleration phase in the shot sleeve have great influence on the flow pattern of the liquid metal in the shot sleeve. In this paper, a three-dimensional model based on the SOLA-VOF algorithm was developed and used to simulate the flow of melt in the shot sleeve. The mathematical model was verified by water analog experiments with constant plunger velocities. Based on numerical simulation results, the influences of the plunger acceleration on the wave profile of the liquid metal in the shot sleeve under different fill ratios and sleeve diameters were investigated. The results indicated that in order to avoid air entrapment in the shot sleeve, the optimal acceleration value to the critical slow shot velocity increases with the increase of the fill ratio, and the range of suitable acceleration becomes wider as well. With the same fill ratio, the value of suitable acceleration rises as the plunger diameter increases.

Numerical Simulation Software of Casting Process used for Computer Aided Instruction

2011 ◽  
Vol 399-401 ◽  
pp. 13-16
Author(s):  
Jian Min Zeng ◽  
Jie Liang ◽  
Zhi Liu Hu ◽  
Ping Chen ◽  
Li Hua Liang
Keyword(s):  
Numerical Simulation ◽  
Casting Process ◽  
Simulation Software ◽  
Computer Aided Instruction ◽  
Casting System ◽  
Computer Aided ◽  
Solidification Processes ◽  
Software Utility ◽  
Casting Design ◽  
Filling And Solidification

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

Fatigue Life Prediction in Rapid Die Casting

2008 ◽  
Author(s):  
Chuan Huat Ng ◽  
Karl-Heinrich Grote ◽  
Ru¨diger Ba¨hr
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Fatigue Life ◽  
Experimental Testing ◽  
Die Casting ◽  
Life Time ◽  
Casting Process ◽  
Simulation Software ◽  
Stress Strain ◽  
Fracture Models

During a die casting process, it is very difficult to achieve efficient and correct casting tooling endurance results by the casting designer and foundry man. However, it is very costly and time consuming to predict the tooling endurance with a trial and error method based on expertise and experience. After an extensive fatigue design study, it was possible to develop specimen design models for the simulation of the time and temperature dependent stress-strain and fracture models to determine the thermal fatigue prediction. In this research, stress-strain approach, heat transfer concept and life time calculation methods were used to predict the casting tool endurance by a computer simulation. The thermal stress and heat transfer behaviour analysis were performed using RWP casting numerical simulation software. It is shown that numerical simulation techniques can simulate stress concentration on the specimen surface to thermal behaviour. Furthermore, the result from the specimen based simulation model associated with fracture indicators permits the construction of a life time design curve independent of time and temperature. The fatigue life predicted by simulation based models and the results from experimental testing on real components are very similar. The simulation results showed that they match the experimental results, including a design safety factor.

Numerical Simulation and Optimization on Casting Technique of HT200 Flywheel

2010 ◽  
Vol 97-101 ◽  
pp. 2553-2557 ◽  
Author(s):  
Bin Feng He ◽  
Guo Fa Mi ◽  
Shuang Shuang He
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Cast Iron ◽  
Gray Cast Iron ◽  
Casting Process ◽  
Gating System ◽  
Casting Technique ◽  
Simulation And Optimization ◽  
Casting Yield ◽  
Simulation Results

The Z-CAST software was employed to simulate the casting process of gray cast-iron flywheel. Shrinkage was predicted through analyzing the temperature field and the flow field. According to the simulation results, the gating system was improved to eliminate shrinkage, and the thin, wide ingate was shown that can reduce the shrinkage and increase casting yield.

scholarly journals Numerical simulation and optimization of casting process of copper alloy water-meter shell

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402092345
Author(s):  
Kaikui Zheng ◽  
Youxi Lin ◽  
Weiping Chen ◽  
Lei Liu
Keyword(s):  
Numerical Simulation ◽  
Phase Distribution ◽  
Three Dimensional ◽  
Casting Process ◽  
Element Model ◽  
Casting Defects ◽  
Gating System ◽  
Three Dimensional Model ◽  
Simulation And Optimization ◽  
Water Meter

The water-meter shell has a complex-structured thin-walled cavity, and it can cause casting defects such as shrinkage and misrun. On the basis of structural analysis of a water-meter shell, a three-dimensional model and a finite element model of the water-meter shell were constructed using the SOLIDWORKS and ProCAST software as a modeling tool and a casting numerical simulation tool, respectively. Three processes associated with the bottom gating system without a riser, a step gating system with a preliminary riser, and a step gating system with an optimum riser were successively numerically simulated. The mold-filling sequence, temperature distribution, liquid-phase distribution during solidification, and shrinkage distribution of these three processes are discussed here. The numerical simulation results indicated that optimization of the casting process and the rational assembling of the riser led to the shrinkage volumes at the inlet position, regulating sleeve, and sealing ring of the water-meter shell decreasing from 0.68 to 0 cm3, 1.39 to 0.22 cm3, and 1.32 to 0.23 cm3, respectively. A comparison between model predictions and experimental measurements indicated that the castings produced by the optimized process had good surface quality and beautiful appearance, without casting defects, demonstrating that numerical simulation can be used as an effective tool for improving casting quality.

Application of Numerical Simulation on Cast-Steel Axle’s V-Method Foundry

2010 ◽  
Vol 139-141 ◽  
pp. 576-579
Author(s):  
Guo Fa Mi ◽  
Li Lin Chen ◽  
Hong Yan Nan
Keyword(s):  
Numerical Simulation ◽  
Cast Steel ◽  
Three Dimensional ◽  
Solidification Process ◽  
Casting Process ◽  
Simulation Software ◽  
Three Dimensional Model ◽  
Original Process ◽  
Shrinkage Defects ◽  
Improved Technology

The V-method foundry is an advanced casting technology compared with traditional sand casting. The Pro/E software was used to generate three-dimensional model of cast parts. The solidification process of the automotive axle casting with V-method foundry was simulated by the numerical simulation software, ViewCast. The location and scale of the shrinkage defects caused by the original process were predicted. According to the simulation results, the position of the flange round cooled too fast, which blocked the feeding passage of the round near sprue. The reason was that solidifying sequence was unperfected. The casting process was optimized by means of adding runner and chill. Progressive solidification can be obtained and the shrinkage defects can be eliminated or transferred by the improved technology. The reasonable casting process was obtained and the process has been proofed by the productive practice.

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