A Study of Wave Formation in Shot Sleeve of a Die Casting Machine

1994 ◽  
Vol 116 (2) ◽  
pp. 175-182 ◽  
Author(s):  
T. C. Tszeng ◽  
Y. L. Chu
Keyword(s):  
Wave Front ◽  
Die Casting ◽  
Casting Machine ◽  
Finite Amplitude ◽  
Wave Formation ◽  
Optimum Process ◽  
Shot Sleeve ◽  
Process Variables ◽  
Air Entrapment ◽  
Transient Wave

The objective of this study was to find the optimum process variables for minimizing the amount of air entrapped within the shot sleeve during the slow shot phase of the injection process. To achieve this objective, the relations between process variables (e.g., plunger speed/acceleration, initial filling percentage, sleeve diameter, etc.) and the wave formation within the shot sleeve of a die casting machine have to be determined. For this purpose, a mathematical model has been developed to study the transient wave formation in shot sleeve. The model based on the theory of waves of finite amplitude can predict the critical plunger speed and the profile of wave front, which in turn affect the degree of air entrapment. The optimum plunger speeds for minimum air entrapment are thus determined based on the predicted profile of wave front. Good agreement with the results from water analogue experiments is found.

Simulation Study of Air Entrapment of Melt Flow inside the Shot Sleeve in Die Casting Processes

2011 ◽  
Vol 339 ◽  
pp. 210-214
Author(s):  
Sha Sha Dou
Keyword(s):  
Simulation Study ◽  
Die Casting ◽  
Regression Equation ◽  
Shot Sleeve ◽  
Melt Flow ◽  
Filling Rate ◽  
Air Entrapment ◽  
Low Velocity ◽  
Best Parameters ◽  
Simplified Formula

Based on FLOW3D software to study on the air entrapment of melt flow inside the Show Sleeve in Die-Casting processes, the effect of Die-Casting parameters which are diameter of sleeve, filling rate, low velocity of the plunge, find out the corresponding regression Equation, best parameters and simplified formula of the plunge velocity.

Development of the Gas Induced Semi-Solid Metal Process for Aluminum Die Casting Applications

2008 ◽  
Vol 141-143 ◽  
pp. 97-102 ◽  
Author(s):  
J. Wannasin ◽  
S. Junudom ◽  
T. Rattanochaikul ◽  
M.C. Flemings
Keyword(s):  
Solid Fraction ◽  
Die Casting ◽  
Casting Machine ◽  
Gas Bubbles ◽  
Solid Metal ◽  
Heat Extraction ◽  
Shot Sleeve ◽  
Semi Solid

A simple and efficient rheocasting process that has recently been invented is being developed for aluminum die casting applications. The process called Gas Induced Semi-Solid (GISS) utilizes the combination of local rapid heat extraction and agitation achieved by the injection of fine gas bubbles through a graphite diffuser to create semi-solid slurry. In the GISS process, the die casting machine and the process cycle remain little changed from those of conventional die casting. The GISS unit creates a low solid fraction of semi-solid slurry in the ladle during the ladle transfer to the shot sleeve. The semi-solid slurry is then poured directly into the shot sleeve. This paper presents the detailed description of the process. The results of the semi-solid die casting experiments with ADC10 alloy using the GISS process are also reported and discussed.

Shot Sleeve Wave Dynamics in the Slow Phase of Die Casting Injection

2000 ◽  
Vol 122 (2) ◽  
pp. 349-356 ◽  
Author(s):  
J. Lo´pez ◽  
J. Herna´ndez ◽  
F. Faura ◽  
G. Trapaga
Keyword(s):  
Die Casting ◽  
Wave Theory ◽  
Finite Amplitude ◽  
Slow Phase ◽  
Shot Sleeve ◽  
Viscous Effects ◽  
Filling Fraction ◽  
Wave Dynamics ◽  
Injection Process ◽  
Filling Time

An analysis is carried out on the wave formed during the slow phase of die casting injection processes. Viscous effects are assumed to be negligible and the problem is treated two-dimensionally using finite amplitude wave theory. Two commonly used types of plunger movements are considered, for which all the possible wave profiles are analyzed in depth as a function of the parameters which characterize the law of acceleration applied to the plunger, the initial shot sleeve filling fraction, and the geometrical characteristics of the problem. Different relationships between the relevant dimensionless parameters of the system are proposed, which make it possible to optimize the injection process, and so reduce the entrapment of air which leads to porosity. The validity of such relationships is analyzed in detail for different ranges of parameters. Some of the results obtained for the optimum acceleration are compared with those of other authors and experimental measurements. Finally, a law of plunger acceleration which would completely eliminate the air from the shot sleeve at the end of the slow phase of injection and minimizes the filling time is derived. [S0098-2202(00)02002-2]

Experimental Investigation of Porosity Formation During the Slow Injection Phase in High-Pressure Die-Casting Processes

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
R. Zamora ◽  
J. J. Hernandez-Ortega ◽  
F. Faura ◽  
J. Lopez ◽  
J. Hernandez
Keyword(s):  
High Pressure ◽  
Die Casting ◽  
Three Dimensional ◽  
Casting Machine ◽  
Operating Conditions ◽  
Slow Phase ◽  
Air Entrapment ◽  
High Pressure Die Casting ◽  
Numerical Predictions ◽  
Pressure Die Casting

The air entrapment mechanisms in die-casting injection chambers that may produce porosity in manufactured parts are analyzed in this work using visualization techniques of the flow in a transparent injection chamber model, using water as working fluid. In particular, results for the free-surface profile evolution and for the volume of air remaining in the chamber at the instant at which the water begins to flow through the runner are analyzed for different maximum plunger speeds and initial filling fractions. A comparison between these visualizations and the numerical results of Zamora et al. (2007, “Experimental Verification of Numerical Predictions for the Optimum Plunger Speed in the Slow-Phase of a High-Pressure Die Casting Machine,” Int. J. Adv. Manuf. Technol., 33, pp. 266–276) which were obtained using a three-dimensional numerical model, shows a good degree of agreement. After discussing the air entrapment mechanisms that may produce porosity in manufactured parts, different experiments, which were carried out under real operating conditions using an aluminum alloy in a high-pressure die-casting machine with horizontal cold chamber, will be presented. The die-cavity geometry used in the experiments was appropriately modified to isolate the slow shot phase from the rest of the injection process, and the porosity levels in the manufactured parts were measured using a gravimetric technique. The optimum values of the maximum plunger speed that minimizes porosity in the manufactured parts have been determined. These values are very close to the previous numerical predictions of López et al. (2003, “On the Critical Plunger Speed and Three-Dimensional Effects in High-Pressure Die Casting Injection Chambers,” ASME J. Manuf. Sci. Eng., 125, pp. 529–537)

Study on high-temperature wear and mechanism of Al-Si/graphite composites prepared by the die-casting process

2020 ◽  
Vol 72 (10) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yafei Deng ◽  
Xiaotao Pan ◽  
Guoxun Zeng ◽  
Jie Liu ◽  
Sinong Xiao ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Peer Review ◽  
Die Casting ◽  
Casting Machine ◽  
Injection Pressure ◽  
Casting Process ◽  
Matrix Alloy ◽  
Content Type ◽  
The Matrix

Purpose This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate. Design/methodology/approach Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s. Findings The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C. Originality/value This material has excellent friction properties and is able to maintain this excellent performance at high temperatures. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/

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