Numerical Simulation of Molten Metal-Polymeric Foam Interface Velocity During Lost Foam Casting

Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt

Abstract A novel multiphase flow model is presented for describing the pyrolisis of polymeric foam material in a lost foam casting process. FLOW-3D software (Flow Science, Inc.) has been used to simulate liquid metal filling dynamics and the molten metal-polymeric foam interface velocity in foam patterns of rectangular shape. The effect of the degradation gaseous products on the molten metal-polymeric foam interface velocity was taken into consideration through specially written sub-routing program. The results of the simulations are compared with the previously obtained experimental data for the lost foam iron casting.

Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt

A dynamics of the molten metal-polymeric foam interface has been experimentally observed in “window counter-gravity lost foam casting” of standard GM plates. The observations allowed revealing the effect of the pyrolisis of polymeric foam material on molten metal propagation velocity. FLOW-3D software (Flow Science, Inc.) has been used to simulate liquid metal filling dynamics and the molten metal-polymeric foam interface velocity in foam plates. The effect of the degradation gaseous products on the molten metal-polymeric foam interface velocity was taken into consideration through specially written sub-routing program. The results of the simulations are compared with the experimental data obtained in this study.


2000 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt

Abstract The behavior of liquid metal flow and gas pressure of the evaporated styrofoam pattern decomposition by-products inside the mold and surrounding sand for ductile iron was investigated experimentally. A computer aided thermometric and pressure measurement technique was built to study the heat and pressure related processes in the lost foam casting. A complete pattern of temperature/pressure fluctuations is obtained during the rectangular bar casting. A relationship between liquid metal front velocity, mold filling rate, decomposed EPS gases pressure, distance from the gating and mass of decomposed EPS is found.


2010 ◽  
Vol 210 (14) ◽  
pp. 2071-2080 ◽  
Author(s):  
Ali Charchi ◽  
Mostafa Rezaei ◽  
Siyamak Hossainpour ◽  
Jamal Shayegh ◽  
Sohrab Falak

2000 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt

Abstract Process parameters of lost foam casting were studied experimentally on a commercial scale for two casting techniques: conventional and vacuum assisted gravity castings. The paper presents the results of the foundry experiments focused on the time and spatial dependent aspects of mold filling of a commercial pattern (Disconnect). A small-scale commercial model was designed and fabricated to conduct the experiments to study the thermo- and hydrodynamics of the mold filling characteristics. A high sensitivity linear output capacitive sensor was used to record the rate of sand flow and compaction in flask while horizontal and/or vertical vibrations were applied. A computer aided thermometric technique was used to study the heat-related processes in the counter-gravity lost foam vacuum casting. A complete pattern of vacuum/pressure fluctuations is obtained during counter-gravity vacuum casting using bi-directional vacuum/pressure transducer. Tolerance analyses were performed for styrofoam patterns and their cast products produced by the conventional and vacuum assisted casting procedures.


2014 ◽  
Vol 59 (1) ◽  
pp. 89-95 ◽  
Author(s):  
A. Prstić ◽  
Z. Aćimović-Pavlović ◽  
A. Terzić ◽  
L. Pavlović

Abstract Refractory coatings based on different refractory fillers (talc, cordierite, zircon and mullite) for application in Lost Foam casting process were investigated. Design and optimization of the coatings composition with controlled, rheological properties included, and consequently synthesis were achieved by application of different coating components, namely different suspension agents and fillers and by alteration of the coating production procedure. Morphologic and microstructural analysis of fillers was carried out by means of scanning electronic microscope. X-ray diffraction analysis by means of X-ray diffractometer was applied in determination and monitoring the phase composition changes of the refractory fillers. An analysis of the particle size and shape was carried out by means of the PC software application package OZARIA 2.5. To assess the effects of application of individual refractory coatings, a detailed investigation of structural and mechanical properties of the moldings obtained was performed. Highlight was placed on revealing and analyzing surface and volume defects present on moldings. Radiographic molding tests were carried out by means of the X-ray device SAIFORT type-S200. Attained results are essential for the synthesis of refractory coatings based on high-temperature fillers and their applications in Lost Foam casting process for manufacturing of moldings with in-advance-set properties.


2011 ◽  
Vol 686 ◽  
pp. 371-377 ◽  
Author(s):  
D.H. Hou ◽  
S.M. Liang ◽  
Rong Shi Chen ◽  
En Hou Han ◽  
C. Dong

The lost foam casting (LFC) process utilizes the expanded polystyrene (EPS) foam pattern for the production of metallic components. The thermal degradation of the foam pattern has a significant effect on microstructure of the component. Dendrite coherency is important for the determination of the formation of the solidification structure and cast ability of alloys. The effects of the dendrite coherency on grain size in Mg-4Al alloy have been studied using the two-thermocouple thermal analysis technique in the solidified sample. The results also indicate that the grain size increases with the temperature interval between liquids (TN) and dendrite coherency point (TDCP), The solid fraction at DCP (fsDCP) expressed in percent strongly dependents on the dendrite morphology during solidification.


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