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.

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.

scholarly journals Influence of mechanical activation of a cordierite -based filler on sedimentation stability of lost foam refractory coatings

2019 ◽  
Vol 51 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Marko Pavlovic ◽  
Ljubisa Andric ◽  
Dragan Radulovic ◽  
Sasa Drmanic ◽  
Natasa Djordjevic ◽  
...  
Keyword(s):  
Mechanical Activation ◽  
Positive Influence ◽  
Activation Process ◽  
Test Results ◽  
X Ray Diffraction ◽  
Sedimentation Stability ◽  
Refractory Coatings ◽  
Rheologic Properties ◽  
The Times ◽  
Lost Foam

For the development of the Lost Foam refractory coatings with controlled rheologic properties, the influence of the mechanical activation process on the cordierite-based filler?s properties change was examined. First of all, the test referred to the change of filler particles? size and shape, as well as to dispersion ability and stability of the coating suspension. Cordierite was obtained by synthesis in a solid state, out of the mass consisting of kaoline, alumina, quartz, sepiolite. For characterization purposes, the following methods were used: X-ray diffraction, differential thermal analysis, SEM and optical microscopy. Mechanical activation of filler was performed in a vibrating mill. The upper boundary of the grain size was 100% -30 x 10-6 m, the times were (min): 15; 30; 60. The new composition of Lost foam refractory coatings has been developed with a change of the coating production process, as well. These newly synthesized coatings proved to be effective in terms of a positive influence on a surface quality, structural and mechanical properties of aluminium castings. Test results may be useful to have the Lost Foam refractory coatings specified together with other process parameters used for the production of castings according to this casting method.

Magnetic Properties of Sputtered Fe-O and Co-O Thin Films

1995 ◽  
Vol 403 ◽  
Author(s):  
D. V. Dimitrov ◽  
A. S. Murthy ◽  
G. C. Hadjipanayis ◽  
C. P. SWANN
Keyword(s):  
Grain Size ◽  
Low Temperatures ◽  
Room Temperature ◽  
Oxide Films ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Large Shift ◽  
X Ray ◽  
Grain Size And Shape ◽  
Spherical Grains

AbstractFe-O and Co-O films were prepared by DC magnetron sputtering in a mixture of Ar and O2 gases. By varying the oxygen to argon ratio, oxide films with stoichiometry FeO, Fe3O4, α-Fe2O3, CoO and Co3O4 were produced. TEM studies showed that the Fe – oxide films were polycrystalline consisting of small almost spherical grains, about 10 nm in size. Co-O films had different microstructure with grain size and shape dependent on the amount of oxygen. X-ray diffraction studies showed that the grains in Fe-O films were randomly oriented in contrast to Co-O films in which a <111> texture was observed. Pure FeO and α-Fe2O3 films were found to be superparamagnetic at room temperature but strongly ferromagnetic at low temperatures in contrast to the antiferromagnetic nature of bulk samples. A very large shift in the hysteresis loop, about 3800 Oe, was observed in field cooled Co-CoO films indicating the presence of a large unidirectional exchange anisotropy.

Synthesis and Characterization of New Refractory Coatings Based on Talc, Cordierite, Zircon and Mullite Fillers for Lost Foam Casting Process

2014 ◽  
Vol 59 (1) ◽  
pp. 89-95 ◽  
Author(s):  
A. Prstić ◽  
Z. Aćimović-Pavlović ◽  
A. Terzić ◽  
L. Pavlović
Keyword(s):  
Microstructural Analysis ◽  
Casting Process ◽  
Lost Foam Casting ◽  
X Ray Diffraction ◽  
X Ray ◽  
Software Application ◽  
Design And Optimization ◽  
Refractory Coatings ◽  
Particle Size And Shape ◽  
Lost Foam

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.

MICROSTRUCTURAL CHANGES OF ALUMINIUM ALLOY A319 ON COOLING SLOPE PLATE

2016 ◽  
Vol 78 (6-9) ◽  
Author(s):  
Ahmad Muhammad Aziz ◽  
Mohd Zaidi Omar ◽  
Zainuddin Sajuri ◽  
Mohd Shukor Salleh
Keyword(s):  
Grain Size ◽  
Shape Factor ◽  
Casting Process ◽  
Impact Zone ◽  
Dendritic Microstructure ◽  
Size And Shape ◽  
Cooling Slope ◽  
Grain Size And Shape ◽  
Bottom Zone ◽  
The Impact

The cooling slope (CS) casting process is one of the simplest methods for producing a non-dendritic microstructure. To more clearly determine how this microstructure is formed, specifically in A319, requires an examination of how the dendritic microstructure evolves along the entirety of the CS plate. Yet until now, there are still unclear on the verification of microstructures changes on the CS plate. Based on experimental results, this paper offers an explanation for the mechanism involved in producing a nearly globular microstructure in A319. In addition, the mechanism is verified by using the planimetry method. Moreover a quantitative method is used to determine the grain size and shape factor to provide further support for the proposed mechanism. The solid fraction of α-Al at the impact zone is 70 % which is the highest compared to other zones. Grain size and shape factor shown a decreasing and increasing value respectively from the impact zone until the bottom zone.

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