Dear Mr. Michele,

Please contact A & A Thermal Spray Coatings Link is

https://www.thermalspray.com/wp-content/themes/aaacoating/images/a-and-a-coatings-logo.png

I am attaching some notes from their website- which may be a good reading for you. They are experts in these types of coatings.

Also try :DOW Product :DOWSIL™ 1-2620 Low VOC Conformal Coating

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Dielectric breakdown can be induced by high voltage. The highest voltage required in order for this breakdown to occur can be referred to as dielectric strength. Also , when the insulating properties of a pure material begin to fail, the maximum electric field it can sustain is an intrinsic material property referred to as dielectric strength. It is an electric insulator dielectric coating, a dielectric, which, in the presence of an electric field, may be polarized. Because no free electrons exist to move through the material, no electric flow is allowed when subjected to an external electric field.

Although interrelated, the dielectric constant and dielectric strength should not be confused.

V/m, or volts per unit thickness, is how dielectric strength is expressed. It is independent of the electric field generating electrodes or the material configuration. For insulators, it is an essential property. With the change in dielectric strength, it’s quality changes proportionally.

The Importance of Dielectric Strength

An insulator’s quality is higher, the higher the level of dielectric strength. That means that a coating’s ability to resist or withstand the passage of an electrical current increases with a higher quality – a higher level of dielectric strength.

Certain things have an effect on dielectric strength. These are as follows:

• Where air is concerned, dielectric strength decreases with an increase in relative humidity but increases slightly as the absolute humidity increases.
• Where gas is concerned (i.e., sulfur hexafluoride, nitrogen), with increased humidity, it normally decreases.
• With increased frequency, it decreases.
• With increased operating temperature, it decreases.
• With increased sample thickness, it decreases.

Dielectric Strength of Certain Substances

Various substances have differing dielectric strengths. Here are some common materials examples (strength measured in MV/m):

• Waxed paper – 40 to 60 MV/m
• Diamond – 2000
• Mica – 118
• Distilled water – 65 to 70
• Polyethylene – 19 to 160
• Benzene – 163
• Window glass – 9.8 to 13.8
• Alumina – 13.4
• Air – 3

The measure of dielectric strength is V/m in SI (international system of measurement). That’s volts per meter. You may also see MV/m (mega volts per meter, as used above), or V/cm (volts per centimeter), and so on. Volts per mil is a common dielectric strength measurement in the United States.

Dielectric Coatings

Interference coatings, thin film coatings, or dielectric coatings are deposited on a substrate and consist of thin transparent dielectric material layers.

As an example, one electric insulator is dielectric paint. Through the application of an applied electric field, they can be easily polarized.

Interference coatings, the application of which requires precision, are used in industries such as medical, defense, and aerospace for things like semi-conductors and in electronics.

To change the reflectivity of optical surfaces, a type of dielectric coating is used and referred to as optical coatings.

For radiofrequency applications, dielectric coatings provide shielding.

There are also dielectric mirrors. Dialectics stacks are used, rather than to maximize reflectivity, to minimize it.

Additional dielectric coating applications:

• Heat dissipation for thin metal parts or PCBs
• For conductive surfaces – additional protection provided
• In small motors – laminations
• RFI shielding
• Transformer turns

Can Your Company Benefit From Dielectric Coatings?

If your company is involved in any of the industries mentioned above, or if you feel that dielectric coatings are something from which you can benefit, don’t hesitate to contact one of our knowledgeable representatives. We can help you analyze the needs of your company and help to provide appropriate coating solutions.

A&A Coatings has served numerous industries for over 70 years. We use proven methods and materials with which to offer a plethora of benefits where parts, components, machinery, and various surfaces are concerned.

Call or email us today to find out more about utilizing the electric arc spray process for your coatings!

The measurements of tensile strength and elongation at break were carried out according to the ISO 37 standard. For investigation of the dielectric strength ܧୠ behaviour of the virgin and modified silicone rubbers, a new methodology was developed. It is, at the same time, highly reliable and efficient, saves time and reduces material consumption in comparison to previously reported methodologies. The key component of this methodology is a specifically developed test facility. Furthermore, the methodology comprises determinations for easy preparation and handling of high-quality test specimens. This test method provides various advantages over other methods that have previously been used for measurement of the fundamental quantity ܧୠ value of silicone rubbers. Both technical and economic demands are satisfied. The new facility also enables cost-effective routine tests in material research laboratories. The high quality of the obtained test results was verified by statistical analysis based on the 2-parameter Weibull distribution function. The investigations revealed that the virgin translucent silicone rubber has a large elastic region with an acceptable plastic deformation and also provides an AC 50 Hz dielectric strength of approximately 24 kV/mm for 0.5 mm thickness. These values enable considering the tested translucent silicone as replacement material for an opaque elastomer that is currently used for a rubber stress cone of HV cable accessories. Unfortunately, its optical transmittance is poor compared to optically clear transparent silicone rubbers. On the other hand, the mechanical properties of virgin transparent silicone rubbers do not comply with those demanded from push-on stress cones. In particular, their elongation at break is considered too low for that application. However they provide the AC dielectric strength values in either 28 kV/mm or 29 kV/mm for 0.5 mm thickness, which are higher than those of the translucent type. Moreover, it was found that the post-curing process does not provide viii BAM-Dissertationsreihe a positive impact on the ultimate elongation of silicone rubbers. Hence, the elongation at break of virgin transparent silicone rubbers must be improved before they can be used as insulating material for a rubber stress cone. In addition, the influence of mechanical tensile stress on the dielectric strength of the virgin translucent silicone rubber was investigated. The results show that mechanical tensile stress does not negatively influence on dielectric strength of such silicone rubber, so it can be well-operated under combined electrical and mechanical stresses. Beside the improvement of optical PD detection performance in the translucent silicone insulation materials, the influence of fluorescent dye’s modification was investigated. The results indicate that the commercially available fluorescent dyes of 0.02 wt. % mixed into the translucent silicone polymer do not negatively influence on the ܧୠ value of such silicone material. So an optically compatible silicone rubber is perfectly suitable for the fabrication of novel fluorescent silicone optical fibres, which can be integrated into the modified transparent rubber stress cones of HV cable terminations.

Hello Michele,

there is a well suited material with high gap (4,8 eV) and high break down voltage (> 2MeV/cm). This is insolating ß-Ga2O3.

With regard

R. Mitdank