New Applications for Sapphire: Aerospace & Defense, Part 1 of 3

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Range of sapphire products available from Rubicon Technology including large optical windows and other shapes for aerospace and defense.

Sapphire’s unique properties make it a perfect material for high-performance applications due to its optical transparency, physical strength, resistance to abrasion and corrosion, temperature durability, chemical inertness, and bio-compatibility. As a result, it is perfectly suited for extreme environments where material durability is just as important as optical clarity.

One extreme use case is in the aerospace and defense industry where there’s a need for rugged windows for targeting pods and missile domes, most notably for the US F-35 fighter jet, that may come in contact with harsh conditions from the harsh, gritty desert with extremely high temperatures to high altitudes with extreme low temperatures.

Market research firm Yole Developpement determined that non-substrate applications for sapphire in the defense, semiconductor and other applications represent 25% of the sapphire industry revenue in a new study.  The market represents a solid growth opportunity for sapphire makers.

While there is opportunity, innovation is needed.  Sapphire traditionally has been limited to smaller shapes and sizes using traditional growth methods.  As sensor technology and applications, in defense and aerospace in particular, have evolved, the size requirements for sapphire windows have grown substantially.  One company that is innovating sapphire crystal growth is Rubicon Technology.

In a recent paper, Rubicon’s Dr. Jonathan Levine, Director of Technical Business Development, detailed how Rubicon successfully produced very large sapphire blanks using a highly modified horizontal directional solidification process. This new method, named the Large‐Area Netshape Crystal Extraction (LANCE) system is currently able to produce crystals of several different orientations. The company plans to produce sapphire windows as large as 36 x 18 x 0.8 inches.

For Further Reading

Clearlysapphire.com Blog, Opportunities for Sapphire: New Applications & Markets Explained, http://blog.clearlysapphire.com/?p=426

Clearlysapphire.com Blog, How Large Can You Go? Sapphire Windows Grow Up and Across, http://blog.clearlysapphire.com/?p=409

Rubicon Technology, Synthesis and characterization of large optical-grade sapphire windows produced from a horizontal growth process, http://www.rubicontechnology.com/sites/default/files/Synthesis%20and%20Characterization%20of%20Large%20Optical%20Grade%20Sapphire%20Windows.pdf

How Large Can You Go? Sapphire Windows Grow Up and Across

 

Dr. Jonathan Levine, Director of Technical Business Development, Rubicon Technology, at SPIE Defense, Security and Sensing 2013

SPIE Defense, Security and Sensing 2013 was held last week in Baltimore, MD.  There was a very interesting paper on large sapphire optical windows.  Rubicon Technology’s Dr.  Jonathan Levine, Director of Technical Business Development, talked about recent advances in making very large sapphire optical windows from his paper, “Synthesis and Characterization of Large Optical-Grade Sapphire Windows Produced from a Horizontal Growth Process,” that he presented at the conference.

As sensor technology and applications, in defense and aerospace in particular, have evolved, the size requirements for sapphire sensor windows have grown substantially. Dr. Levine detailed how Rubicon successfully produced very large sapphire blanks using a highly modified horizontal directional solidification process. This new method, named the Large‐Area Netshape Crystal Extraction (LANCE) system is currently able to produce crystals of several different orientations weighing up to 50 kg with plans to expand the process to larger 100 kg sapphire crystals.

Based on a different technique than Rubicon’s ES-2 method, Levine’s team used the LANCE method because it produces plates or slabs of sapphire instead of cylindrical boules.  Using LANCE is advantageous since the near-net shape dramatically reduces machining and associated fabrication costs.  Further, since the melt is horizontal, capillary forces play a minimal role during growth and the crystal is not limited in size or thickness as compared to edge‐defined film-fed growth (EFG) crystals.

According to Levine, Rubicon has been able to synthesize several prototypes up to 1.75 inches thick, 14 inches wide and 20 inches long. The research sets the standard for high quality monolithic sapphire sheets large enough for use as seamless integrated optical windows in both military and civilian applications.

Sapphire is very good for defense and aerospace applications due to its excellent transmission in the UV through IR spectrum, high impact durability, and corrosion resistance in harsh environments.  Sapphire applications include missile domes, transparent armor systems, FLIR and enhanced vision systems for aircraft, and shaped optics for land, air and sea vehicles.

For Further Reading

Rubicon Technology, Rubicon Technology Develops New Sapphire Crystal Growth Platform to Manufacture Large Optical-Grade Windows for Military and Industrial Applications, http://phx.corporate-ir.net/phoenix.zhtml?c=215281&p=irol-newsArticle&ID=1724966&highlight=

SPIE Defense, Sensing and Security 2013, http://spie.org/x6765.xml?WT.svl=mddce7

Rubicon Develops New Sapphire Growth Platform to Make Large Optical Windows

Sapphire Windows in Lockheed Martin f-35 Lightning Joint Strike Fighter

Sapphire Windows in Lockheed Martin f-35 Lightning Joint Strike Fighter

There are a lot of ways to make large commercial sapphire crystals.  But none of them really work for making large sapphire windows using sapphire’s a-plane. We mean really wide so that they can be used in a military plane as a targeting system window.  So, the Air Force Research Laboratory (AFRL) asked Rubicon Technology to develop a new growth platform for very large polished sapphire infrared (IR) windows.  The project is supported by a grant from the AFRL, with a total value of $4.7 million over three years.

Sapphire is perfect for military and other high-performance applications due to its hardness and strength, transparency in the visible and IR spectrum, thermal conductivity, thermal shock resistance, abrasion resistance, high melting point and chemical inertness.  The project will begin with intermediate sizes, then will step it up to windows as large as 36 x 18 x 0.8 inches.

Why do we need this new method?  Existing methods used to produce sapphire windows don’t meet the demands of military applications for thickness and size.  Rubicon’s new technological platform will grow panels approximately two inches thick, which can be cut into multiple windows of varying thickness.  The new method also allows growth of very large windows up to 36 x 18 inches. This is an improvement over smaller faceted windows that require piecing together for large applications.

The sapphire windows for the AFRL will be applied to fighter jet targeting systems. For example, the Lockheed-Martin F-35 Lighting Joint Strike Fighter’s fuselage has a durable sapphire window in the fuselage for use by the Electro-Optical Targeting System (EOTS).  The sapphire is preferred due to its durability, hardness and strength and the way it allows transmission light in the IR spectrum.

Links:

Lockheed-Martin F-35 Lightning II Joint Strike Fighter, http://airsoc.com/articles/view/id/4fe4b7f8c6f8fa2443000009/lockheed-martin-f-35-lightning-ii-joint-strike-fighter

Clearlysapphire.com. http://www.clearlysapphire.com/Optical__Lasers_Windows_.html

Rubicon Technology, http://rubicon-es2.com/index.php?page_id=23

LEDs Shed Light on the US Navy

 

The guided-missile destroyer USS Chafee (DDG 90) departs Joint Base Pearl Harbor-Hickam. (U.S. Navy photo by Mass Communication Specialist 2nd Class Mark Logico)

The USS Chafee (DDG90) has become the first US Navy ship to be fitted with all-LED lighting.  More than 600 LED lighting fixtures provide light for the guided missile destroyer based in Hawaii.  The Navy expects to save more than $50,000 per year using the new lighting system installed by Energy Focus Inc.

According to a post on the Armed with Science blog, Ben Hatch, an electrical engineer at the Naval Surface Warfare Center Carderock Division – Ship Systems Engineering Station in Philadelphia, who oversaw the installation, said, “The longer lifespan also results in a huge amount of savings in regards to maintenance.  LEDs last 50 times longer than the incandescent meaning the lights only need to be replaced every six years compared to what was every other month.”

The Naval Sea Systems Command plans on installing the fixtures aboard in combatant and amphibious ships over the next several years as part of the Navy’s maritime energy strategy.  The next ship up for the retrofit is the USS Preble (DGG88).

For Further Reading:

Armed with Science, USS Chafee is Now First Ship to Receive Complete LED Lighting Upgrade

LEDs Magazine, Energy Focus LEDs light US Navy ship top to bottom, http://www.ledsmagazine.com/news/9/1/5