1. December 2015
We think of barren mountaintops, desert valleys, and dark ocean depths as the world’s most extreme environments. But the man-made world has harsh conditions of its own. Think battlefields, oil refineries, and nuclear power plants.
To work in the world’s most extreme environments — natural or man-made — we must craft materials and components that can stand up to these conditions. Glass and glass-ceramics manufactured with exact precision and superior technology can stand up to these extreme environments and complete some of the world’s toughest tasks. Here are just six examples of glass materials that can take on this challenge.
Space: Space is an unforgiving place — extreme temperature fluctuations and cosmic radiation are constant threats. For that reason, the cameras attached to modern spacecraft and satellites are equipped with special optical glass that, due to its radiation-resistant characteristics, can withstand cosmic radiation as it hurtles through space. Aboard the Philae lander, which traveled millions of miles over 10 years to Comet 67P/Churyumov-Gerasimenko, is a camera system equipped with special SCHOTT glass that was engineered to resist cosmic radiation. The camera’s lenses functioned as designed when Philae landed, and the camera systems captured the comet’s distinct surface properties.
Back on Earth, spectroscopic telescopes like the Hobby-Eberly Telescope are analyzing the light from stars in our galaxy and far beyond. By using mirror blanks made of SCHOTT ZERODUR® glass-ceramic, researchers can maintain high spectroscopic accuracy due to the material’s extremely low co-efficient of thermal expansion. The telescope’s 150 spectrographs, made of BOROFLOAT® glass with exceptionally high transparency, very low thermal expansion and high chemical durability, are busy mapping the three-dimensional positions of one million galaxies, and researchers hope these calculations will explain the mysterious force called dark energy.
Chemical pipelines: Millions of gallons of fluid flow through tubes, pipelines, and storage tanks every day. This liquid, whether crude oil, a caustic chemical compound, or simply a boiling liquid, can be corrosive and dangerous to the touch. However, quality-control experts still need to monitor the pipes to ensure oil and chemicals effectively flow from point A to point B. For that reason, manufacturers produce these vessels with small windows known as sight glass.
This glass must withstand high pressures and chemical corrosion in order to give experts a clear view into pipes. The addition of boron in the production process gives BOROFLOAT®, used for sight glass, clear optics and low thermal expansion, as well as chemical resistance. Plus, it’s chemically stable and is highly resistant to the acids, bases, and alkalis that can run through these vessels.
The battlefield: Whether by land, sea, or air, warfighters remain at the ready to defend. Strengthened armored glass for land vehicles helps to keep the warfighter safe under the most demanding conditions. The glass offers the transparency needed to maneuver rugged terrains, but can also withstand bullets and shrapnel.
Other glass technologies, like IR lenses and multispectral glasses, are used in helicopters, on warships, and in on-the-ground helmets to provide the warfighter with enhanced optical capabilities. These lenses focus light of different wavelengths into one optical path, and can reduce the size, weight, and power of military vehicles and everyday equipment. Used on the ground in Enhanced Night-Vision Goggles (ENVG), these lenses enhance situational awareness during scouting missions in rugged and difficult terrain, or during a firefight when tensions are high and events are rapidly unfolding.
Nuclear plants: In theory, nuclear fission is a simple process — uranium atoms are split to release energy. But in order to perform this explosive process safely, nuclear engineers rely on hundreds of controls, sensors, and monitors to oversee fission within the reactor. Glass-to-metal sealed electrical penetrations assemblies (EPAs) are a key component in this. They are designed to provide a leak-tight pass-through for power, control, and instrumentation cables through the containment structure while maintaining the pressure boundary integrity, even in cases of severe accidents. To maintain this safety level, the EPAs must be based on inorganic, non-aging sealing technology using glass, which is proven to withstand radiation, humidity, and fluctuating temperatures for many years.
Fire-rated windows and doors: The best construction practices fade from our view — by design. Take, for example, fire-rated windows and doors — critical components of any building designed to stand up to high heat and withstand thermal shock, but ones that often get passed by without a second thought. These materials must perform flawlessly when a fire breaks out and temperatures can reach north of 1,090 degrees. Transparent glass-ceramics rated for fire doors and windows give us something to look at (or through), and keep the flames contained when the heat is turned up.
Glass-ceramic materials like PYRAN® Platinum are being increasingly used in building design, as these transparent windows remain clear during a fire and allow occupants to find exit paths and safely flee from smoke, gas and flames. The chemistry of these glass-ceramic panels prevents it from expanding when the temperature rises, which ensures it won’t break even after long periods of heat exposure. And because PYRAN® Platinum has a thermal expansion coefficient close to zero, it won’t shatter when it is dosed with water and cooled down.
Fireplaces, cooktops, and grills: We describe our homes as cozy and comfortable — certainly not extreme. But the living room fireplace, kitchen cooktop, outdoor grill can generate extreme temperatures that requires glass capable of containing and controlling the heat. Proper glass-ceramic barriers protect the home from the flames and smoke in a fireplace and woodstove while simultaneously radiating its heat uniformly throughout a room.
In the kitchen, CERAN® glass-ceramic cooktops allow home cooks to sauté at high temperatures for long cook times by resisting thermal expansion. On the patio, glass-ceramic viewing windows, made of NEXTREMA® glass, built into grills provide a view into the 500-degree grilling surface — no need to lift the lid. And even if a quick thunderstorm comes rolling through, the glass-ceramic is manufactured to withstand rapid temperature fluctuations, preventing it from shattering when exposed to the elements. Glass plays a key role in keeping homeowners safe from the hot surfaces throughout their home.
Taming the extreme
Glass is sometimes thought of as a fragile material, but highly specialized glass and glass-ceramics can withstand some of the world’s most extreme environments, from nuclear reactors to the battlefield. Due to specialized manufacturing processes, glasses and glass-ceramics often perform better than other materials in these extreme environments. For that reason, glass remains one of the world’s toughest materials.