Designing effective thermal conductivity of materials of …
We introduce the phenomenon of golden touch from myth to thermotics. We define golden touch as extending the core property to a shell with an extremely small core fraction. We obtain the requirement of golden touch by making the effective thermal conductivity of the core-shell structure equal to the thermal conductivity of the core. …
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Measurement of the effective thermal conductivities of
It is well known that the effective thermal conductivity of bonded molding sands depends on the volume fraction, thermal conductivity and arrangement of the components e.g., sand particles, bonding medium and air. The arrangement of components is known to be affected by particle size distribution, average size and shape. In this study, an …
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Measurement of the effective thermal conductivities …
It is well known that the effective thermal conductivity of bonded molding sands depends on the volume fraction, thermal conductivity and arrangement of the components e.g., …
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Thermal Properties of 3D-Printed Sand Molds
Specific heat capacity (Cp), density (ρ), and thermal conductivity (λ) of phenolic-bonded 3D-printed sand (3DPS) molds have been determined in the temperature range of 20–1400 °C using differential scanning calorimeter (DSC), dilatometer, and hot wire method. The results have been used to simulate the thermal gradient in a sand mold …
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Chromite sand with high thermal conductivity | HAIXU
Chromite Sand in the foundry industry. Its properties enable the material to be used in high duty grey iron and steel foundries as core and mould making sand. Its high thermal conductivity gives it good chilling properties, low thermal expansion gives rise to good dimensional stability. Its basicity being close to neutral allows the use of a ...
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Why Chromite Sand | Minerals Technologies Inc.
High thermal conductivity. The Thermal Conductivity of chromite sand is higher than the other commercially available foundry moulding sands. This results in a mild chilling of the surface and a thicker solidified skin. This thicker skin improves the casting surface …
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Thermal conductivity of sands | Heat and Mass …
The thermal conductivity of four sands is measured using laboratory thermal probe. It is found that thermal conductivity increases with decrease of porosity and …
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Heat Transfer Properties of Some Kinds of Sand …
The values of thermal conductivity of the molds which consisted of silica, zircon, chromite sands decrease gradually from room temperature to 1,000°C. The mean values of …
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Chrome Sand Applications
Alongside high thermal conductivity, chrome sand has low thermal expansion(1). The following are the uses of foundry chrome sand: Green Sand. ... Unlike conventional sand moulds, chromite moulds can be hard to recover and reuse should there be moderate-to-high amounts of silica present. This is due to a greater likelihood of the chrome becoming ...
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Chromite Sand
Physical properties of Chromite Sand. Melting point of 2150°C. Good thermal conductivity. Good resistance to thermal shock. Excellent resistance to metal penetration or burn-on. Resists slag attack. High dimensional stability.
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Chromite Sand | Chromite Sand
Chromite sand has established mounting awareness for several years, as a very effective moulding material for a multiplicity of different reasons: ... *Low thermal expansion. *High thermal conductivity. *Good refractoriness. *Efficient Substitute of Zircon Sand. Item: Unit: Index: Cr2O3 % 46.0min: SiO2 % 1.0max: FeO % 26.5max: CaO % 0.30max ...
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REFRACTORY CHROMITE SAND | Chromite Sand …
Refractory Chromite Sand is mainly used in chrome-magnesia or magnesia-chrome bricks. Chrome ore can overcome the typical disadvantages of magnesia (shrinking tendency and high-temperature …
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All About Casting — Sandcasting, that is! | by Autumn …
Chromite Sand. Chromite sand, FeCr2O4, ... This thermal conductivity helps dissipate heat from the casting and plays a significant role in the overall cooling of the casting.
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Comparative experimental study of sand and binder for …
Zircon and chromite sand have low thermal expansion but good thermal conductivity which is responsible for their excellent chilling properties [16, pp. 920–921]. However, these are much more expensive and heavier than silica. Bauxite is an abundant mineral but not much in use in foundries currently. It has the prospect of resolving some ...
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(PDF) Determination of Chromite Sands Suitability for
For the study has been typed reference sand with chemical properties, physical and thermal, treated as standard, and the sands of the regeneration process and the grinding process. Using these ...
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Thermal physical and mechanical properties of …
thermal conductivity of the sand cores relative to SiO 2 sand. A good agreement was obtained between simulations and experiments is the 'dipping trials'. The temperature …
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Thermal properties of cement mortar with different mix proportions
Our results indicate that, for a cement mortar with a 28-day compressive strength in the range of 6–60 MPa, thermal conductivity, specific heat and thermal diffusivity are in the range of 1.5 ...
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46% Chromite sand with high thermal conductivity
Chromite sand is produced from washed natural chromite ore. There are few sediment and silica residues after the washing and magnetic removal process. 46% Chromite sand with high thermal conductivity works well to make the casting steel cool. Especially for large casting, chromite sand can make it solidify in a proper order.
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Aggregate Molding Materials | SpringerLink
Other sands are applied for special castings, when higher fire resistance, better thermal conductivity, or lower coefficient of thermal expansion are required.
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Chromite Sand | Minerals Technologies Inc.
Cr2O3 -46% min. SiO2 -1% max. AFS of 25-70 with a broad distribution. Low thermal expansion. High thermal conductivity. Hevi-Sand® Chromite Sand is a versatile, unique aggregate, unlike ordinary chromite sands. …
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Measurement of the effective thermal conductivities of …
of the effective thermal conductivity of sand molds at temperatures below 600~ The predic- tions show good agreement with measured :her- mal conductivities of dry molding sands bonded ... olivine and chromite sands using the thermal probe method. They found that an optimum binder content and an optimum initial moisture content exist for dry ...
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2 …
1.1.4Chromite Sand Chromite sand occurs naturally and it consists of oxides of chrome and iron. It has sub-rounded grains form with more polished surfaces with 85 AFS fineness number and it does not require crushing and can be used directly in the mould. High thermal conductivity which
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Change of chromite sand after heating | HAIXU
The thermal conductivity of chromite sand is several times greater than that of silica sand, and the chromite sand itself undergoes solid-phase sintering during molten metal pouring, which is beneficial to prevent the penetration of molten metal. In the foundry industry, chromite sand is mainly used as the mold, core surface sand and anti ...
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Determination of Chromite Sands Suitability for Use in …
thermal shock resistance, compressive strength and thermal conductivity [1-6]. Problems related to the availability of raw materials as well as ... reclaimed chromite sand are used in foundries, a ...
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High thermal conductivity chromite sand AFS45-50
High thermal conductivity chromite sand AFS45-50 is a foundry-grade chromite sand. With a high Cr2O3 content of more than 46% and SiO2 of less than 1%, the chromite sand works excellent as core sand, molding sand, shape sand, and facing sand for casting. The chromite sand from Haixu Abrasives gets high thermal and chill performance after water …
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Thermal properties of sand and mineral flours | SN Applied …
The accuracy of the equipment is within 5% of the thermal conductivity and 10% of the thermal diffusivity. Three granular samples were selected as matrix material, i.e., quartz sand, quartz flour and limestone flour. Their grain size is given in Table 1 and ranges from < 0.006 mm to > 0.4 mm.
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Chromite: The Next Generation | HA International LLC
Chromite sand has been applied continuously in foundries since the 1960s, as exemplified in Picture 4. The CastTherm 45 product is the conventional material used by steel foundries for mold and core production where high thermal conductivity, heat resistance, high dimensional stability and, casting surface finish are critical.
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Effect of Temperature on Chromite-Based Moulding …
burnings [2]. This compound has very high thermal conductivity [3] and linear thermal expansion of chromite grains at 1400 °C is ca. 1.4% [2]. Density of chromite sand ranges between 4.5 and 4.8 ...
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Foundry Grade Chromite Sand
Hevi-Sand® Foundry Chromite Sand is used in foundries worldwide due to its unique combination of properties. Hevi-Sand® is produced from high-grade foundry chromite which has been specially treated for use as a mold and core media in the production of quality castings. Hevi-Sand® is selectively mined from ore in the Bushveld Complex in South
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Assessment of South African Chromite Sand for Binder …
[5]. These limitations have made silica sand unsuitable for many types of casting. Chromite sand with its superior properties, such as good thermal conductivity, and high dimensional and thermal stability, has now been seen as an alternative to silica sand. In recent times, most chromite sand used in the international foundry industry ...
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