scholarly journals Disposal of gases emitted during Lost Foam casting process

2021 ◽  
Vol 29 (2) ◽  
pp. 60-67
Author(s):  
V.S. Doroshenko ◽  
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.


2001 ◽  
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.


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

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.


Author(s):  
X. J. Liu ◽  
S. H. Bhavnani ◽  
R. A. Overfelt

A thermometric technique has been developed to study the thermal characteristics of the foam-metal interaction in the lost foam casting process. A cylindrical foam pattern and heated steel block have been used to estimate the endothermic losses associated with the thermal degradation of the expanded polystyrene at the metal front. Thermocouple readings have been analyzed to determine the temperature of the kinetic zone between the advancing metal front and the receding foam pattern. The heat transfer coefficient between the metal front and the foam pattern has been calculated from the thermal data at the simulated metal front. The results confirmed that the endothermic degradation of the polystyrene pattern at the metal front introduced a steep thermal gradient in the metal and a consistently increasing heat flux. It is found that the heat transfer coefficient, initially 150 W/m2·K increases to 220 ~ 300 W/m2·K during the process. Foam density has marginal effect on the heat flux and heat transfer coefficient, whereas the increase of simulated metal front velocity enhances the heat transfer at the metal front. The kinetic zone temperature is measured to be in the range of 150 to 290°C with an average of 200°C and a gaseous gap size of 1 to 4 cm.


2011 ◽  
Vol 148-149 ◽  
pp. 1198-1201
Author(s):  
S. Izman ◽  
Amirreza Shayganpour ◽  
M.H. Idris

Cast aluminium alloys often contain microstructural defects resulting from the casting process such as porosity. Developments of Lost foam casting (LFC) process is considered as one of the most rapid in casting technology owing to its unique advantages on energy savings and capabilities to produce castings with thin sections. In the present research, experimental investigations in lost foam casting of aluminium-silicon cast alloy, LM6, were conducted. The main objective of the study was to evaluate the effect of different pouring temperatures, slurry viscosities, vibration times and sand sizes on the porosity of castings. A stepped pattern was used in the study and the focus of the investigations was at the thinnest 3 mm section. A full 2-level factorial design experimental technique was employed to plan the experiment and subsequently identify the significant factors which affect the casting porosity. The result shows that increasing in the pouring temperature decreases the porosity in the thin-wall section and finer sand size is more favourable than coarse size for LFC mould making process.


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