Reflectivity
Our ThermaGold reflectivity in the infrared equals and often exceeds that of a freshly vapor-deposited
gold. Because of its outstanding cleanability, stability, reflectivity and high purity (min. 99.9%), Raytheon
Infrared Systems chose Therma-Gold as their coating standards for thermal control.
Emissivity
The emissivity of Therma-Gold is extremely low. Actual measurements by the Raytheon Infrared Systems
and Highland's optical equipment indicate an emissivity is equal to the theoretical emissivity of pure gold.
(If emissivity equals (1-R), then Therma-Gold is .015).
Substrates
Therma-Gold is usually applied over metal substrates including , but not limited to, Aluminum, Beryllium,
Copper, Stainless, Molybdenum, and Titanium.
Uniformity
ThermaGold is an electrodeposition process and therefore is not line-of-sight dependent as is the case
with vapor deposited coatings. It can coat the inside of light pipes or other shapes with parallel walls or
cavaties. The uniformity of the coating can be controlled to prevent distortion of the optical figure.
Temperature
Due to its extreme purity will not discolor when heated. As an example, it will withstand 60 minutes at
1000 F in air atmosphere without color change.
Polarization and Scatter
When applied to metal optics, there is no perceptible change in performance in either the S or P
polarization plane. ThermaGold does not increase scatter, in fact, certain customers have actually
reported reduced scatter after Therma-Gold coating
Beryllium (Electroless Nickel)
About Electroless Nickel…
Accoding to Brushwellman, electroless nickel is the number one beryllium. It can be used where the
optical surface is a hard polished electroless nickel. Mirrors of this type are made to resist plastic
deformation due to severe G-loads or other working stresses, such as Infrared wavelengths of light. The
optical surface of S-200F is usually a hard polished coating of electroless nickel with a thickness of 24 to
150 micrometers. Electroless nickel is harder and much easier to polish than bare beryllium. The
beryllium mirror's stiffness, low weight, stability, and micro-yield strength make it perfect to suit
aerospace and military needs.
Plating and Coating…
Because of the chromate conversion coatings also developed for aluminum, the electroless nickel has
enhanced resistance to salt spray and high teperature oxidation. Many metals may have been
electroplated on beryllium, but such systems are generally not in extensive use today. However,
electroless nickel plating is extensively applied to beryllium, especially in the optics field.
Corrosion Resistance...
Corrosion and oxidation in air is minimal up to temperatures of about 1400 degrees because Beryllium
develops an adherent, protective oxide coating in air. However, it is important to know that in other
environments, the protection isn't adequate and proper care must be exercised to avoid corrosion.
Beryllium is highly susceptible to localized pitting when in contact with the chloride and sulfate ions
contained in ordinary water. So, exposure to tap water should be kept to a minimum and always followed
by a DI water rinse, and then drying. Seawater is massively corrosive to beryllium. Handling beryllium
parts with a finished surface should be done with extra care because a finger print left on the surface will
disrupt the effectiveness of the final etch or coating.
Other Metals Used:
* AlBeMet
* Aluminum Series (Plate &Anodize)
* Aluminum Die Cast (Plate & Anodize)
* Titanium (Plate & Anodize)
* Steel
* Stainless Steel
* Copper Alloy
* Zinc Alloy
* Zinc Die Cast
* Beryllium
* Molybdenum
Capabilities
Highland can work with a wide range of metals, from hi-tech to the plating of precious metals, like gold to
chrome, black chrome, bright brass in polished and antiqued variations. Highland has a state-of-the-art
anodizing line and can also provide chem film and paint services.
Finishes
OVER 150 Finishes and Surfaces!
Finishes and Services:
* Anodizing: Sulfuric & Chromic Acid / Type I, II & III / Architectural
* Anodizing Beryllium
* Gold and Thermagold: Metals and Plastics
* Black Chrome
* Chrome: Polish, Satin, Bright
* Black Nickel Nickel: Bright Nickel, Satin Nickel, Black & Super Black, & Dull
* Brass: Polish, Satin, Bright, Antique, Antique Bronze, Antique Copper
* Paint, Powder Coat to FAA Specifications
* Chemfilm: Iridite/Alodine
Decorative Finishes Available:
