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Hiskey's LANL work creates fireworks. See below.

 

It’s pretty easy to take the art of welding for granted. But like the proverbial poor patch of ground, “it’s what holds the rest of the world together.”
As Stan David of DOE’s Oak Ridge National Laboratory points out, half of the products that make up the U.S. gross national product contain at least one welded joint.
 

Scanning electron micrograph of a crystal-growth pattern in a weld

Recently ORNL, with a vigorous welding research program that continues to make significant contributions to welding science and technology, concluded a successful collaboration with DOE’s Sandia National Laboratories and Idaho National Engineering and Environmental Laboratory aimed at a difficult problem: how to weld advanced light-weight aluminum alloys for industries that require ever increasing precision and quality.

“Every time a new material is introduced, it’s a new challenge for those who provide the joining technologies,” David says.

New and promising aluminum alloys have been kept off production lines because they aren’t amenable to welding. In a “system of labs” approach, ORNL, Sandia and INEEL applied their particular strengths to explore new technologies for welding the new alloys.

Arc welding is a commonly used method for melting and joining two pieces of metal. Unfortunately it can’t be used at high speeds because the metal cannot be sufficiently heated. On the other hand, laser welding can be used at high speeds, but only if the pieces fit neatly and are very clean. Aluminum also tends to reflect the laser light’s energy, decreasing coupling of the laser with the material.

The collaboration considered a hybrid approach to the problem—they paired the advantages of laser and arc welding. The team has laid the foundation for a combined process that has the potential for allowing the laser to better penetrate the alloy.

The three labs have contributed their own strengths in the project: Sandia developed the process by combining plasma arc with laser welding; INEEL explored the gas-metal arc process with the laser; and ORNL’s team of David, John Vitek, Suresh Babu and Mark Richey performed analytical studies on the welds’ microstructures and developed computer models to predict weld-pool shape and properties.

The program has generated extensive interest by U.S. industry in the new laser-assisted welding program and led to acceptance of a follow-on DOE Office of Industrial Technology multilab program with Sandia, INEEL, ORNL and DOE’s Y-12 Plant. ORNL also signed a memorandum of collaboration with Coventry University in England, where a similar laser-assisted arc welding process is under development.

David says that because new alloys bring with them new joining problems to solve, the collaboration has laid important groundwork for putting these important materials in the marketplace. “The three labs have succeeded where, alone, they probably wouldn’t have,” David says.

The collaboration’s biggest winners, however, will be U.S. industries.

Submitted by Oak Ridge National Laboratory
 
 
 

In a remote, aging building at DOE's Los Alamos National Laboratory, chemist Michael Hiskey toils away, concocting substances never seen in nature.

Hiskey's LANL work creates fireworks.

He adds a little of this to a little of that and, voila, new molecules are born, as often as one a week. What Hiskey is creating are high-nitrogen energetics, or explosives with better bang for the buck.

“In some ways, it really is a trial-and-error process,” Hiskey explained. “We try to make explosives with stability, performance and other specific characteristics, but really all we do is make what Mother Nature allows us to make.”

One discovery soon could dazzle millions of tourists. Hiskey and his colleagues have created low-smoke pyrotechnics—fireworks with deep, bright colors that generate virtually none of the smoke or ash of traditional black powder fireworks.

Disney Corp. recently licensed the invention, which holds the potential for an entirely new class of spectacular fireworks that are safe and effective for theatre, films, concerts, political rallies, sporting events, and even table-top educational demonstrations.

The lack of smoke means fireworks that need only a fraction of the metallic salts that color traditional fireworks. Byproducts are harmless nitrogen, carbon dioxide and water. Hiskey’s pyrotechnics produce more intense colors in a wider variety of hues and are lighter, safer to handle and leave much less toxic residue in soil and water.

Los Alamos’ low-smoke pyrotechnics are the first major advance in the field in over 100 years. Funding for his work came from DOE Defense Programs and from the Department of Defense.

Another of Hiskey’s discoveries, an efficient, high-performance explosive called TNAZ or 1,3,3-trinitroazetidine, is used by the U.S. military.
Hiskey earned his Ph.D. in explosives chemistry from New Mexico Institute of Mining and Technology at Socorro, a small school recognized world-wide for its research and development in explosives. He has worked at Los Alamos for nearly nine years. 

Submitted by Los Alamos National Laboratory