The permeability of Lost Foam pattern coatings for Al alloy castings

2008 ◽  
Vol 43 (16) ◽  
pp. 5441-5447 ◽  
Author(s):  
W. D. Griffiths ◽  
P. J. Davies
Keyword(s):  
Al Alloy ◽  
Alloy Castings ◽  
Foam Pattern ◽  
Lost Foam

CFD Simulation of Fluid Flow Through Porous Media: Application to Decomposed Gases Flow Through Foam Pattern in Lost Foam Casting

Materials ◽  
2003 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt
Keyword(s):  
Cfd Simulation ◽  
Reynolds Numbers ◽  
Phase Flow ◽  
Flow Through Porous Media ◽  
Foam Material ◽  
Element Analysis ◽  
Wide Range ◽  
Flow Through ◽  
Foam Pattern ◽  
Lost Foam

Numerical simulation of decomposed gases through foam pattern was conducted using finite element analysis. A new kinetic model is proposed for gaseos phase flow between molten metal and foam material. The computations were performed for a wide range of Reynolds numbers. The results of the simulations are compared with the experiemental data obtained in this study.

Reference Dies for the Evaluation of Tensile Properties of Gravity Cast Al-Si Alloys: An Overview

2014 ◽  
Vol 794-796 ◽  
pp. 71-76 ◽  
Author(s):  
Anilchandra R. Adamane ◽  
Elena Fiorese ◽  
Giulio Timelli ◽  
Franco Bonollo ◽  
Lars Arnberg
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Scientific Literature ◽  
Die Casting ◽  
Al Alloy ◽  
Casting Defects ◽  
Automotive Components ◽  
Foundry Alloys ◽  
Alloy Castings ◽  
Gravity Cast

Aluminium-Silicon (Al-Si) alloys are the most extensively used Al foundry alloys and are widely used in gravity die-casting (GDC) of automotive components. Reference dies are used to characterize the tensile properties of the castings. Among the various die configurations, the ASTM B-108 (also called the Stahl Mold), and the AA Step Mold are most popular in the foundries. Several modifications to the standard dies have been suggested in the scientific literature to obtain better mechanical properties in minimizing casting defects. This work reviews the scientific literature on the effect of different reference dies on the porosity and tensile properties of the Al alloy castings.

Comparative Study of Surface Contaminated Layer on Titanium Aluminum Alloy and Titanium Alloy Investment Castings

2021 ◽  
Vol 1035 ◽  
pp. 602-607
Author(s):  
Zhi Hua Feng ◽  
Xian Fei Ding ◽  
Xin Feng ◽  
Hai Nan ◽  
Ai Bin Zhang
Keyword(s):  
Titanium Alloy ◽  
Aluminum Alloy ◽  
Comparative Study ◽  
Chemical Reaction ◽  
Microhardness Measurement ◽  
Ceramic Mold ◽  
Al Alloy ◽  
Ti Alloy ◽  
Titanium Aluminum ◽  
Alloy Castings

A comparative study of the surface contaminated layer formed by chemical reaction between ceramic-mold and titanium aluminum alloy castings or titanium alloy castings were carried out. The morphology, thickness and hardness of the surface contaminated layer were characterized by means of metalloscopy and microhardness measurement. The results show that surface contaminated layers formed between Ti-Al alloy castings and ceramic-mold, also formed between Ti alloy castings and ceramic-mold. The surface contaminated layers of Ti-Al alloy castings were continuous and compact, their thickness was about 0~90 μm. The surface contaminated layers of titanium alloy castings were not even, their thickness was 0~900 μm. Titanium alloy is more liable to react with the ceramic -mold than the Ti-Al alloy.

Hot cracking of binary Mg–Al alloy castings

2006 ◽  
Vol 417 (1-2) ◽  
pp. 230-238 ◽  
Author(s):  
G. Cao ◽  
S. Kou
Keyword(s):  
Hot Cracking ◽  
Al Alloy ◽  
Alloy Castings

Light Alloy Castings for Automotive Applications: The Case of Al vs. Mg

2006 ◽  
Vol 519-521 ◽  
pp. 1801-1808 ◽  
Author(s):  
Carlos H. Cáceres
Keyword(s):  
Cast Iron ◽  
Primary Energy ◽  
Al Alloy ◽  
Iron And Steel ◽  
Automotive Components ◽  
Casting Alloys ◽  
Structural Applications ◽  
Alloy Castings ◽  
The Cost ◽  
Alloy Cast

The economical and environmental effects of mass reduction through Al and Mg primary alloys substitutions for cast iron and steel in automotive components are discussed using M.F. Ashby’s penalty functions method. The viability of Mg alloy substitutions for existing Al alloy cast components is also considered. The cost analysis shows that direct, equal-volume, Al alloy substitutions for cast iron and steel are the most feasible in terms of the CAFE liability, followed by substitutions involving flat panels of prescribed stiffness. When the creation of CO2 associated to the production of Al and Mg is considered, the potential gasoline savings over the lifespan of the car compensate for the intrinsic environmental burden of Al in all applications, while electrolytic Mg substitutions for cast iron and steel are feasible for equal volume and panels only. Magnesium produced by the Pidgeon thermal process appears to be too primary energy intensive to be competitive in structural applications. Magnesium substitutions for existing Al alloy beams and panels are generally unviable. The current higher recycling efficiency of Al casting alloys confers Al a significant advantage over Mg alloys.

Thermal Analysis during Solidification of Mg-4%.wtAl Alloy during Lost Foam Casting Process

2011 ◽  
Vol 686 ◽  
pp. 371-377 ◽  
Author(s):  
D.H. Hou ◽  
S.M. Liang ◽  
Rong Shi Chen ◽  
En Hou Han ◽  
C. Dong
Keyword(s):  
Thermal Analysis ◽  
Grain Size ◽  
Casting Process ◽  
Expanded Polystyrene ◽  
Solidification Structure ◽  
Lost Foam Casting ◽  
Dendrite Morphology ◽  
Dendrite Coherency ◽  
Foam Pattern ◽  
Lost Foam

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.

scholarly journals Synthesis of the new lost foam refractory coatings based on talc

2021 ◽  
pp. 111-111
Author(s):  
Marko Pavlovic ◽  
Jasmina Nikolic ◽  
Ljubisa Andric ◽  
Dejan Todorovic ◽  
Katarina Bozic ◽  
...  
Keyword(s):  
Grain Size ◽  
Positive Influence ◽  
X Ray Diffraction ◽  
Size And Shape ◽  
Refractory Coatings ◽  
Alloy Castings ◽  
Grain Size And Shape ◽  
Time Required ◽  
The Cost ◽  
Lost Foam

This paper is focused on the preparation procedures, using talc-based filler to improve the rheologic properties of the lost foam refractory coatings. Talc, with grain size of 40 mm, was mechanically activated in a vibration mill over the following times: 10, 20 and 30 min. Depending on the time required for the mechanical activation, the change in the filler grain size and shape was analysed along their effects on the talc-filled lost foam coating dispersion ability and stability. In order to characterize the filler, the following methods were used: X-ray diffraction, scanning electron microscopy and optic microscopy. The coating compo-sition was tuned by choosing the suitable grain size and shape factor of the activated filler. In addition, different coating components (additives, solvent) were applied to alter the coating generation procedure. It was shown that the application of this type of the lost foam refractory coatings - water-based coatings - have a positive influence on quality of the aluminium alloy castings, which contributes to reducing the cost of cleaning and processing of the castings. Also, alcohol-based refractory coatings with talc-based activated fillers were tested and used to have the castings produced in the sand moulds.

Measurement of Kinetic Zone Temperature and Heat Transfer Coefficient in the Lost Foam Casting Process

2004 ◽  
Author(s):  
X. J. Liu ◽  
S. H. Bhavnani ◽  
R. A. Overfelt
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Casting Process ◽  
Lost Foam Casting ◽  
Foam Pattern ◽  
Lost Foam ◽  
The Heat Transfer Coefficient ◽  
Zone Temperature

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.

DAMPING CAPACITY AND MECHANICAL PROPERTIES OF Zn-Al ALLOY CASTINGS

1981 ◽  
Vol 42 (C5) ◽  
pp. C5-935-C5-940 ◽  
Author(s):  
T. Otani ◽  
K. Hoshino ◽  
T. Kurosawa
Keyword(s):  
Mechanical Properties ◽  
Damping Capacity ◽  
Al Alloy ◽  
Alloy Castings
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