scholarly journals Range Of Thermal Conductivity Changes Of Wet Green Foundry Sand During Casting Solidification

2015 ◽  
Vol 60 (3) ◽  
pp. 2391-2395 ◽  
Author(s):  
P.K. Krajewski ◽  
G. Piwowarski
Keyword(s):  
Thermal Conductivity ◽  
Numerical Calculations ◽  
Cooling Curves ◽  
Green Sand ◽  
Mould Material ◽  
Sand Mould ◽  
Water Vaporization ◽  
Moulding Sand ◽  
Complex Temperature ◽  
Pure Cu

AbstractThe paper presents results of measuring thermal conductivity of green sand mould material and time of castings solidification evaluated from cooling curves. During the experiments pure Cu (99,8 %) plate was cast into the examined sand moulds. Basing on the measurements it was stated that thermal conductivity of the moulding sand has complex temperature variability, especially during the water vaporization. It was confirmed that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured casting. The obtained dependence should be used in the numerical calculations to improve their accuracy.

scholarly journals Experiment and Numerical Modelling the Time of Plate-Shape Casting Solidification vs. Thermal Conductivity of Mould Material/ Eksperyment I Modelowanie Numeryczne Czasu Krzepniecia Odlewu Płyty W Funkcji Przewodnictwa Cieplnego Materiału Formy

2014 ◽  
Vol 59 (4) ◽  
pp. 1405-1408 ◽  
Author(s):  
P.K. Krajewski ◽  
G. Piwowarski ◽  
P.L. Zak ◽  
W.K. Krajewski
Keyword(s):  
Thermal Conductivity ◽  
Initial Temperature ◽  
Mass Density ◽  
Variable Parameter ◽  
Numerical Calculations ◽  
Cooling Curves ◽  
Mould Material ◽  
Plate Shape ◽  
Complex Temperature ◽  
Thermo Physical Properties

Abstract The paper presents results of measuring thermal conductivity of sand mould material and time of castings solidification evaluated from cooling curves and from Nova Flow & Solid numerical calculations. During the experiments pure Al (99,95%) plate was cast into the sand moulds. The analysed variable parameter in numerical calculations was mould thermal conductivity of fixed value taken from the range 0.5-0.9 W/(mK). Other mould parameters (initial temperature, mass density, heat capacity) and thermo-physical properties of liquid and solid casting were taken invariable. Basing on the measurements it was stated that thermal conductivity of the moulding sand has complex temperature variability, especially during the water vaporization and the obtained dependence should be used in the numerical calculations to improve their accuracy.

scholarly journals Thermal Properties of Foundry Mould Made of Used Green Sand

2016 ◽  
Vol 16 (1) ◽  
pp. 29-32
Author(s):  
P.K. Krajewski ◽  
G. Piwowarski ◽  
J. Buraś
Keyword(s):  
Thermal Conductivity ◽  
Temperature Field ◽  
Thermal Properties ◽  
Mould Temperature ◽  
Green Sand ◽  
Foundry Sand ◽  
Temperature Range ◽  
Heat Diffusivity ◽  
Water Vaporization ◽  
Moulding Sand

Abstract The paper presents results of measuring heat diffusivity and thermal conductivity coefficients of used green foundry sand in temperature range ambient − 600 °C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements of the mould temperature field during the solidification of the casting, the temperature relationships of the measured properties were evaluated. It was confirmed that the obtained relationships are complex and that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured and solidified casting.

Investigation on the Influence of Different Additives on Properties of Green Sand Mould

2020 ◽  
Vol 978 ◽  
pp. 29-33 ◽  
Author(s):  
Prafulla Kumar Sahoo ◽  
Sarojrani Pattnaik ◽  
Mihir Kumar Sutar
Keyword(s):  
Compression Strength ◽  
Grain Shape ◽  
Coconut Shell ◽  
Green Sand ◽  
Green Strength ◽  
Optimum Quantity ◽  
Binder Type ◽  
Coconut Shell Ash ◽  
Sand Mould ◽  
Moulding Sand

Green sand mixtures which are used for moulding purposes in foundry industries should possess sufficient green compression strength, flowability, toughness and air-permeability. Usually, the aforementioned properties for a particular casting differ due to variation in composition of the moulding sand mixtures, sand grain shape and size, bonding capacity of the binder, type and quantity of additives used, etc. The present work focuses on the effect of various additives namely, camphor powder, coconut shell ash, mixture of camphor powder and coconut shell ash at diverse proportions on permeability and green compression strength of the sand moulds. The quantity of the aforementioned additives for experimentation was varied from 0.5 to 3.5 wt. %. It was found that the mould’s permeability increased on addition of 1 wt. % additives for all cases. Similarly, the optimum quantity of additives that needs to be added to the sand mixtures for enhancing green compression strength was found to be 2 wt. %. Among all the additives used for improving the mould’s permeability, substitution of camphor exhibited best results. The green compression strength was found to be highest for the coconut shell ash containing sand mould. The moulding sand containing a combination of camphor powder and coconut shell ash between 1 to 2 wt. % exhibited fine mould permeability along with sufficient green strength.

scholarly journals High Temperature Thermal Properties of Bentonite Foundry Sand

2015 ◽  
Vol 15 (2) ◽  
pp. 47-50 ◽  
Author(s):  
P.K. Krajewski ◽  
J.S. Suchy ◽  
G. Piwowarski ◽  
W.K. Krajewski
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Temperature Field ◽  
Thermal Properties ◽  
High Temperature ◽  
Mould Temperature ◽  
Green Sand ◽  
Foundry Sand ◽  
Temperature Range ◽  
Water Vaporization

Abstract The paper presents results of measuring thermal conductivity and heat capacity of bentonite foundry sand in temperature range ambient - 900­­°C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements of the mould temperature field during the solidification of the casting, the temperature relationships of the measured properties were evaluated. It was confirmed that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured casting.

Multi Response Optimization of Green Sand Moulding Parameters Using Taguchi-DEAR Method

2019 ◽  
Vol 895 ◽  
pp. 1-7
Author(s):  
M.J. Sandeep ◽  
Patel G.C. Manjunath ◽  
Ganesh R. Chate ◽  
Mahesh B. Parappagoudar ◽  
Umesh M. Daivagna
Keyword(s):  
Casting Process ◽  
Silica Sand ◽  
Cow Dung ◽  
Green Sand ◽  
Pareto Analysis ◽  
Design Flexibility ◽  
Complex Shapes ◽  
Response Optimization ◽  
Sand Mould ◽  
Moulding Sand

Green sand casting is treated as the most versatile casting process due to their excellent design flexibility that offer complex shapes and ability to reclaim silica sand. The modern foundries are looking for alternate moulding materials to partially replace the high cost silica sand. Cow dung is a naturally available eco-friendly binding as well as additive material and is used to partially replace the silica sand. Improper choice of the combination of moulding sand variables, such as degree of ramming, percentage of cow dung, percentage of clay, and percent of water will affect the moulding sand properties and thereby quality of casting. In the present work, Taguchi method is employed to plan and conduct experiments. Pareto analysis of variance is performed to know the contribution of variables on the moulding sand properties (i.e. compression strength, permeability, loss-on-ignition). Taguchi DEAR method is used to determine the single optimal levels of input factors that enhances the performances of all the sand mould properties. Percent of clay and cow-dung found to be the most dominating factor towards all the sand mould properties.

Investigation of flowability of the green sand mould by remote control of portable flowability sensor

2021 ◽  
Vol 112 (2) ◽  
pp. 70-76
Author(s):  
D. Abdulamer
Keyword(s):  
Remote Control ◽  
Wireless Transmission ◽  
Green Sand ◽  
Compaction Process ◽  
Moulding Process ◽  
Control Behavior ◽  
Sand Mould ◽  
System 1 ◽  
And Control ◽  
Non Destructive

Purpose: The useful data and information during the sand compaction process steps should be collected. Direct measurement methods of the sand mould properties during the actual moulding process are not adopted yet. Design/methodology/approach: In this work, a remote control system [1] have been integrated into a new flowability sensor [2]. Findings: To overcome the complexity of the tools and equipment that existed in laboratory, and in foundry. Research limitations/implications: In order to investigate, and control behavior of the moulding process of bentonite-bonded green sand process, the sensors have been equipped with the Bluetooth technology for a wireless transmission of the measured data to computers. Originality/value: This technique contributes to improve of the compaction process based on the non-destructive tests, enhances prediction of the optimum parameter conditions, and reduced the energy, and the compaction time consumed for the green sand moulding process.

scholarly journals A General Expression for the Stagnant Thermal Conductivity of Stochastic and Periodic Structures

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
X. Bai ◽  
C. Hasan ◽  
M. Mobedi ◽  
A. Nakayama
Keyword(s):  
Thermal Conductivity ◽  
General Expression ◽  
Metal Foam ◽  
Solid Angle ◽  
Periodic Structures ◽  
Three Dimensional ◽  
High Thermal Conductivity ◽  
Numerical Calculations ◽  
The One ◽  
Good Agreement

A general expression has been obtained to estimate thermal conductivities of both stochastic and periodic structures with high-solid thermal conductivity. An air layer partially occupied by slanted circular rods of high-thermal conductivity was considered to derive the general expression. The thermal conductivity based on this general expression was compared against that obtained from detailed three-dimensional numerical calculations. A good agreement between two sets of results substantiates the validity of the general expression for evaluating the stagnant thermal conductivity of the periodic structures. Subsequently, this expression was averaged over a hemispherical solid angle to estimate the stagnant thermal conductivity for stochastic structures such as a metal foam. The resulting expression was found identical to the one obtained by Hsu et al., Krishnan et al., and Yang and Nakayama. Thus, the general expression can be used for both stochastic and periodic structures.

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