INTRODUCING –  Crushable Fused Silica cores

Fused Silica is fundamentally pure silicon dioxide in amorphous form. It is made by heating suitable sands or crystalline quartz to melting temperature and quenching before crystalline rearrangement can occur.

There are applications which do not require the full temperature capability of MgO, or may demand a better electrical isolation at modest temperatures. Compatibility with thermoelement wires should be considered for high temperature use in thermocouples.  Performance results with heater elements should be proven by testing.

For modest temperature use, fused silica promises some very interesting insulation resistance results.

1)  low power heaters?
2)  high dielectric and current leakage requirements?
3)  high frequency signal transmission
4)  possible performance improvements for high temperature insulation resistance?
5)  possible cost advantage compared to type 1 MgO materials?

TATEHO OZARK has searched for a suitable supply for years to address various inquiries, with limited success.  However, after a series of trials we have identified a material that can be successfully fabricated and gives outstanding performance results.  It is still a developmental product, and we are still tightening the fabrication limits.  In the meantime, the product is of excellent compositional quality, and we expect to make progress on dimensional and mechanical issues quickly.

Early trials have given some excellent electrical results, exceeding the ability of instruments to measure the resistivity above 1 Tera-ohm.

Typical AnalysisGrade FUS
Fe2O3140 ppm
K2O*<30 ppm
Na2O*<20 ppm

* Powder analysis of volatile species expected to be zero in finished insulator

Grade FUS is still a developmental product by TATEHO OZARK.  It is challenging to make dimensional targets because drying and firing behavior is not fully predictable in advance.  Please advise of any critical dimensional limits.  Generally speaking, the following guidelines can be expected:

Grade FUS fused silica crushable insulators - SPECIFICATIONS
Outside Diameter
0.050"0.50" or ?+/- 3 %
Hole Size (1-hole)0.020" or 12% of OD60% of OD 3% of OD
Hole Size (multi)0.020" 25% of OD or 100% of wall3% of OD
Length1" 4" or 20 x ODas fired