University of New Orleans Researcher Al Daech is afraid of heights. Not a good phobia to have when your research involves space shuttles, fuel tanks and other big, space-age equipment.
He’s been trying to conquer his fears since 1981. That’s when his work on corrosion fighting collided with his fear of heights. As a Martin Marietta consultant, Daech found himself on a narrow bit of scaffolding 450 feet in the air, inspecting one of the external fuel tanks on the STS-I Columbia, the first space shuttle.
“There was intense pressure on NASA at the time to be first with cutting technologies and achievements (because of earlier Russian successes in the space race). A delay may have crippled NASA,” he recalls.
Years later at NASA, new knowledge and extreme circumstances in space caused Daech to reevaluate corrosion protection. Upon discovering a material in space called 5eV atomic oxygen that corroded metals and materials more severely than on earth, Daech and others sought alternatives to combat corrosion and create new coatings. “The atomic oxygen was eating the coating and even some of the plastic. Until then, I had never seen corrosion like this,” said Daech recalls. “We had our work cut out for us.”
“Sound easy?” Daech laughs before continuing softly, “We actually did it.” After developing the first simulator of atomic oxygen degradation of aerospace materials for NASA, Daech was then able to work on a new corrosion-resistant coating — essentially a protective paint that’s applied to the external fuel tanks still used on the space shuttle. The coating has since been adopted by other aerospace companies.
“Eventually, we discovered that we could alloy nontraditional metals into aluminum and make them corrosion resistant,” Daech explains. And now, as we usher in a new millennium, Daech’s work continues, although at a lower altitude. His current corrosion inhibitor research has garnered considerable attention because of its potential economic and environmental impact on various industries.
In the current wave of environmental prudence and cost-cutting consciousness, Daech, Dr. Nikhil Sarkar from the LSU Dental School (who worked on the adhesion aspect of the research), and researchers at University of New Orleans Gulf Coast Region Maritime Technology Center (GCRMTC) have developed a new environmentally friendly corrosion inhibitor that could save the military and commercial airline industry millions of dollars in their war against corrosion — one of the costliest problems in the nation — in terms of money, materials, energy and even human life.
“Corrosion costs the government billions of dollars on military aircraft, ships, vessels, torpedoes and other things. With some of the current inhibitors — using heavy metals such as chromium, lead and cadmium — found to be toxic, UNO’s inhibitor could be a great cost-saving, environmentally conscious benefit. Currently, billions of dollars are expended to help retard or prevent corrosion,” said Environmental Engineer Bill Strasburg of John J. McMullen Associates Inc. and a retired civilian Navy employee, who directed the UNO inhibitor testing for NavAir. The inhibitor was tested in attempt to eliminate hazardous materials and waste on Navy planes, ships and other things.
The new corrosion inhibitor, a coating for aluminum, has other benefits besides combating rust. It is not carcinogenic. It applies easily, and that means it’s more user friendly, safer for the environment, and will help control hazardous material costs, disposal and handling.
Sidebar: Creating The CoatingUsing his more than 40 years of experience working for and/or with the chemical and paint industries, Martin Marietta, NASA, the EPA and UNO’s Gulf Coast Region Maritime Technology Center, Daech — along with UNO researchers — focused on creating a new pigment (for a reformulated coating) that is both effective in corrosion prevention in aluminum and environmentally acceptable.
First, a sample coating was created and applied to hand-cleaned aluminum alloys. The adhesion quality ranged from good to outstanding. When the coating was examined by an independent testing organization, who administered the ASTM-117B (salt fog) test for 168 hours on scribed panels, no corrosion occurred.
“Experiments with the UNO coating were successful the first time we tried. We seemed to discover a longevity better than chromium, at least in our lab experiments. It’s better than the requirements for chromium,” Daech said.
The test also revealed that UNO’s coating inhibited corrosion as much as chromium without the hazardous materials. Daech is rightfully proud. “What we have to offer is something that tested better than anything in the world. This also complies with the environmental regulations, plus it has the capability to eliminate the problem of carcinogenic coatings. This is the transition from ‘we don’t give a damn if we pollute the world to we better stop polluting the world’.”
“The new inhibitor is key, particularly with the OSHA limitation on chromates. OSHA is defining — even more tightly — the permissible exposure-level limit over an eight-hour day. It’s changing from 100 micrograms per cubic meter in an air situation to 0.5 micrograms per cubic meter,” Strasburg said.
OSHA has reportedly levied $10,000 a day fines against companies when chromium invaded the water supply. “Remember, the entire fleet of military and commercial planes are protected from corrosion by chromates in coatings. The new UNO inhibitor could help with the problem. The coating could prevent corrosion while boasting an environmentally friendly status,” Strasburg said.
“Companies are at the mercy of the elements, and the Navy has been testing submissions (for new corrosion inhibitors) from around the world. Apparently, they haven’t found anything that was satisfactory, except ours,” Daech said.
Currently, Naval researchers in Washington, D.C., have moved the inhibitor research from the 6.1 stage (laboratory) to 6.2 stage (pilot program). “This research is innovative. It has great potential. The commercial application would help with pollution and waste. It could solve a lot of hazardous materials’ problems. This contains no hazardous materials,” said Dr. Azar Nazeri, research engineer at the Naval Research Lab in Washington, D.C.
Looking ahead, Daech added, “I’m still working on my fear of heights, too!”
Sidebar: Corrosion: Cause and EffectCorrosion happens when oxygen and moisture mix, creating what we usually think of as rust. When you seal out the moisture and oxygen (what is called in the trade passivating the surface), you protect the object from that corrosion. It can’t oxidize and thus its life is extended.
“Corrosion is one of the biggest losses the nation endures in terms of materials. And the energy losses resulting from the corrosion are also tremendous,” said John Crisp, dean of UNO’s College of Engineering and Executive Director of the GCRMTC.
Ships, bridges and other marine structures all need to be corrosion-proof. In the past, various chromium-based inhibitors (in other coatings) have been applied to aluminum surfaces. These include strontium chromate, zinc chromate and chrome phosphate. But these are heavy metal-based and largely carcinogenic. In addition, the EPA has shown that the lead-based coatings were causing health complications in children. The import of the information from the EPA proves stunning. Small amounts of chromic acids or potassium dischromate can cause kidney failure, liver damage, and blood disorders. Chromate mists entering the lungs may eventually cause lung cancer. In most instances, these chromium-based compounds are now prohibited.
At lower levels (the EPA quantifies it as “chrome three” or below on a daily, allowable pollutants-emissions level), chromium is considered non-carcinogenic. So when current coatings containing chromium must be refurbished, such as on military and civilian airplanes, the entire plane must be disassembled and treated to convert the chromium substance from “chrome six” to “chrome three.” Only then can the plane be cleaned and repainted.
The process requires that all the parts and metal have to be washed and the water filtered into a sanitary disposal system for storage or discarding. The conceivable health effects are so serious that the run off from a plant or its sewer is limited to one part per billion of the chromium, an almost immeasurable amount. In fact, chromium is so dangerous that regulators limit chromium and chromates in coatings more severely than cyanide and some poisonous gases.
Other organizations are involved, including OSHA. Officials from that industry began investigating solvents because of concern with smog, the ozone layer and for other reasons (solvents and pigments are two primary ingredients of paint). “Essentially, researchers today are left with a paint without a useable (meeting environmental guidelines) solvent or pigment,” said Daech.
Some information contained in this article was obtained from the EPA’s Web site at www.epa.gov.
For more information on corrosion inhibitors, contact Joseph White, Marketing and Communications, University of New Orleans, Lakefront Campus, New Orleans, LA 70148-2755; phone 504/280.6622; fax 504/280.7160; e-mail email@example.com.