The history of innovative materials in architecture is replete with cases of technology transfer. Many new products—such as aerogel or memory foam—originate from aerospace or military research and development programs. However technology transfer takes time and effort, and requires advocates willing to face the risks associated with bringing a product or process to a new market.
Gary Cola, president and chief technology officer of Flash Bainite Steel, is such an advocate. A self-proclaimed “car guy, stamping die maker, and self-taught metallurgist,” Cola became intrigued with the flash bainite process developed by the defense industry to create lightweight, high-strength weldable armor. Having pursued a career in the Detroit tooling industry (he founded die-stamping company Master CNC Inc. in 1993), Cola intuited the advantages of high-performance steel for nonmilitary uses. Though he struggled with early variants of the material, after an “Edisonian approach of thousands of seemingly unrelated tests,” Cola developed an optimized version of the flash bainite process for automotive applications. Since a vehicle’s mass correlates directly to its fuel consumption, the flash-processed steel, with the estimated ability to increase fuel efficiency in a vehicle by 6 percent to 8 percent by reducing 10 percent of its weight, is critical to achieving Corporate Average Fuel Economy standards.
So what exactly is this new method of steel-making? Flash-processing is an approach to creating advanced high-strength steels from commercial off-the-shelf versions by changing the materials’ microstructures via rapid heat treatment. Ambient-temperature steel is heated in an electromagnetic induction unit in less than 10 seconds—the unit increases in temperature by 752 F per second, to over 1,832 F. Even more suddenly, the material is cooled in a water bath in less than one second. The result is a highly workable material with a complex microstructure that exhibits a greater strength and ductility than in its preprocessed form. According to an article in Industrial Heating, “flash-processed steels have higher specific strengths, meaning that they are stronger per unit density than most other materials and can potentially provide lightweighting of automotive parts.” Although some materials, such as aluminum, are lighter than standard steel, their lower specific strengths require more material to be used for the same application—thus resulting in heavier components. Cola’s version of the process—named “bainite” after particular cubic microstructures that form after cooling—produces a steel alloy that is 10 percent stronger than conventional steel, with an elastic yield strength of 1,200 MPa and ultimate strength of 1,600 MPa. The process is also relatively energy efficient, requiring less than half a kilowatt per kilogram of steel—and eliminates the tempering phase altogether.
And although Cola’s primary focus is automobiles, he is eyeing building construction as the next breakthrough market for his technology. As in cars, the case for using flash-processed steel in buildings is based on optimizing resources. Reducing the weight of steel components saves energy in the manufacturing, transportation, and construction phases. Although transportation represents a much larger part of the life cycle of a car than a building, there are many additional reasons to pursue architectural lightweighting. Smaller components that perform the same task occupy less volume, thus utilizing space more efficiently. “In the building industry, the attractiveness of Flash is likely more the ability to reduce costs with smaller cross section steel since the fuel economy argument goes away once the steel is delivered to the worksite,” Cola says. “For example, Flash Rebar reinforced concrete pillars could lead to smaller columns and increased square footage to lease, thus increasing the value of the building while lowering the initial build cost.” Thus, more floor area could be dedicated to occupant functions or outdoor spaces and reduced structural depth would result in taller ceiling heights—or a lower overall building height. There is also a compelling argument for reducing the self-imposed weight of structures. “Imagine bridges that could be lighter simply because the tonnage of the steel can be used to hold up the vehicle load, not requiring as much strength to hold up the bridge itself,” Cola says.
The concept of lightweighting reminds us of Buckminster Fuller’s famous query “How much does your house weigh?”—a question devised to focus popular attention to an underappreciated aspect of buildings. A key part of Fuller’s 1920s marketing campaign for his prefabricated Dymaxion house, this query has resurfaced within sustainable design circles and challenges opposing strategies like increasing thermal mass. Lightweighting also points to—and undermines—a popularly held assumption about building longevity. Some studies reveal that many buildings are razed before reaching their anticipated lifespan, for example, thus complicating traditional life cycle measures. An approach to designing architecture with a more flexible lifespan would emphasize aspects of disassembly and material reuse—considerations that further elevate the importance of lightness in buildings.
According to Cola, the next step to bringing flash-processed steel to buildings will require developing a thorough business model as well as overcoming challenges concerning industry awareness and building regulations. Preliminary fire safety tests are encouraging, however. “After a 75-minute heating process to over 1,100 degrees F, the Flash test samples still had 45-ksi yield strength when pulled on at 1,112 degrees F,” he says. “This is in stark contrast to A36 steel with 36-ksi yield strength at room temperature.” The value proposition also requires further study, but preliminary estimates are compelling. "The most prevalent and motivating benefit in using Flash Bainite in buildings will be anticipated cost reductions being able to use a steel that is three to four times stronger,” Cola says. “Even reducing the web thickness by only one-third leaves a product twice as strong or more.” The high dent- and penetration-resistance of flash-processed steel may also be of particular interest in high-abuse or high-risk settings, such as in hurricane-prone areas. Cola estimates that smaller architectural components will take a year to commercialize, and larger framing systems will require more time due to regulatory complexity. Nevertheless, Flash Bainite Steel is likely to renew awareness about the benefits of architectural lightweighting. According to Cola, “the sooner Flash is known in the building industry, the sooner this record-setting armor technology can make buildings stronger, lighter, and lower cost too.”