Products

NAIGAI CERABEADS 60

Features

  • As selected raw materials are fired at high temperature (1680°C), the structure of CERABEADS is dense and made of mullite crystals.
  • This product is artificial sand with extremely stable quality.
  • This product is made by firing spherical granules. It is not a crushed product.
  • This product has the following advantageous chemical and physical properties:
    • Uniform component composition
    • Stable grain size distribution and air permeability
    • High refractoriness (SK37, 1825°C)
    • High resistance to wear, crush and thermal shock
    • Little thermal expansion
    • Excellent in fluidity and filling efficiency owing to being spherical

Features

  • As spot sand, face sand for sand casting
  • As stucco material for investment casting
  • As setter for high-temperature furnace
  • As media for fluidized bed

Product lineup

NAIGAI CERABEADS 60 #400

#400

NAIGAI CERABEADS 60 #650

#650

NAIGAI CERABEADS 60 #750

#750

NAIGAI CERABEADS 60 #1450

#1450

Product information

Grain size composition and grain size distribution

Representative value
mesh 36 50 70 100 140 200 280 -280 AFS
μm 425 300 212 150 106 75 53 -53
Product
No.		 #400 16.9 66.4 15.9 0.8         40.1
#500 8.3 35.0 28.8 21.1 6.3 0.6     52.7
#550 5.6 25.8 33.9 26.2 7.8 0.7     56.1
#650   3.3 39.8 42.8 12.7 1.4     65.8
#750   2.3 26.6 36.1 26.8 7.2 0.9   78.3
#850   2.2 26.0 34.4 18.1 13.7 4.8 0.8 85.6
#950   0.9 12.0 16.7 52.6 16.1 1.8   96.7
#1450       3.8 75.3 18.3 2.6   108.7
#1700         1.3 65.1 29.5 4.2 155.5

Comparison with other casting sands

  CERABEADS Zircon Chromite Quartz sand
(Flattery sand)
Powder bulk density
(g/cm3)		 1.69 2.99 2.81 1.58
Refractoriness SK37
(1825°C)		 SK37
(1825°C)		 SK39
(1880°C)		 SK33
(1730°C)
Coefficient of thermal expansion
After 300 sec (%)		 -0.03 0.18 0.26 1.50
Coefficient of heat transfer
(W/m·k)		 0.56 0.80 0.58 0.71
Specific heat
(kcal/g·°C)		 0.44 0.34 0.29 0.27
Main chemical components Al2O3 61%
SiO2 36%		 ZrO2 66%
SiO2 32%		 Cr2O3 45%
Fe2O3 25%
Al2O3 15%
MgO 10%		 ≧SiO2 99%
(1) Powder bulk density As CERABEADS is about half as light as zircon and chromite, it can turn out about twice the number of molds per unit weight, and it can be handled so easily, saving labor and transfer power cost. However, attention should be given to the amount of its binder addition.
(2) Refractoriness Having high refractoriness (SK37, 1825°C), CERABEADS can be used for casting various materials, and there is no need to use sand type distinctly according to material.
(3) Coefficient of
thermal expansion		 Owing to little thermal expansion, CERABEADS is excellent in dimensional precision.
(4) Coefficient
of heat transfer		 As CERABEADS is smaller in thermal transfer compared with other sand types, some special device should be arranged when it is used for a case where a high coefficient of thermal transfer is required.
(5) Specific heat Although CERABEADS is higher in specific heat compared with other sand types, it may be evaluated differently depending on the mold making method or casting method.
Regeneration test

Casting sand is regenerated and reused over and over by undergoing heating and cooling processes. We have looked into variation in the crushability of casting sand through the crushability test (S-6) and variation in explosive thermal expansion through the repeated explosive thermal expansion test according to the Japan Foundry Engineering Society.

(1) Crushability test

This test shows clearly that CERABEADS is lower in crushability compared with other general casting sand types.
From this, CERABEADS is demonstrated as a material excellent in resistance to wear, crush and thermal shock and expected to show high yield ratio when it is used repeatedly as casting sand.

≪Test method≫

1) Sample
The sand volume was adjusted to CERABEAMS 600g to make a test sample.
2) Method of heating to explosive heat temperature
The test sample adjusted to the room-temperature was loaded into an electric furnace maintained at 1300°C. Upon holding there for an hour, the test sample was unloaded from the furnace quickly, and cooled to the room temperature.
3) Crushing method
The test sample heated to the explosive heat temperature and cooled to the room temperature was loaded into a magnetic ball mill of 5L in volume together with 40 pcs of alumina balls of 20Φeach, and crushed for 20 min. After crushing, the grain size distribution was measured and the grain fineness number (AFS) was obtained by calculation. The steps 2) and 3) were repeated 3 times to measure the crushability.
4) Crushability index calculation method
Crushability (%) = (AFS after crushing / AFS of base sand)×100

Crushability test result

(2) Repeated explosive thermal expansion test

The little thermal expansion of CERABEADS is evident in comparison with quartz sand.
When collected, regenerated and reused, its little thermal expansibility can be maintained with practically no change in thermal expansibility through repeated uses. This indicates its stable quality to meet the requirements of dimensional precision, etc.

Coefficient of thermal expansion

If you have any inquiry, please contact the following:

[CERABEADS Sales Sec.]
12-8, Shiokusa-cho, Seto-shi, Aichi 489-0895, Japan
Tel: +81-561-21-3715  Fax: +81-561-21-4141

→For the inquiry form, click here.

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