There's hot news from the deep freeze for brakes. Cryogenics is one of those terms that sounds more like science fiction than science: "The enemy is closing at warp three speed, Captain. We have no choice but to deploy our secret Cryogenic Defense Curtain. It's risky, but it's our last chance to stop them."
In spite of its syllable-level sound of space-age suspense, cryogenics is a real technology that has been around for decades - before Star Trek, before Star Wars, even before Ask Mr. Wizard. It deals with low temperature physics, with what happens to materials, processes, or even human bodies when subjected to ultralow temperatures.
Instead of using it to stop space invaders, however, the automotive industry is considering how cryogenics might be used to help stop cars and trucks. Leading Edge Cryogenics Inc. (LEC) of Camp Verde, Ariz., has been doing research and development in the field of cryogenics for the past several years. The company's special focus has been on enhancing the performance of everyday things, including brake pads. Five patents testify to its success.
According to Richard Jewett, the company's vice president of marketing, cryogenic treatment of brake-pad friction materials results in several performance benefits such as better "green" brake performance, enhanced high-temperature performance, dramatically longer wear, and a reduction in brake noise and dust. How does it do all that?
First of all, this is not a matter of popping brake pads into the freezer overnight. Cryogenics is the deep, deep freeze - -300 degrees F or below - under very tightly controlled and monitored conditions. "Cryogenics is a tool we use in engineering friction materials to create better brake pads," explains Jewett. "Superior performance and wear characteristics are achieved with the improvements made in stronger atomic bonds and the stronger, more uniform micro-structure of the materials."
All this from the big chill? LEC offers test data from Greening Labs in Detroit, Mich., by way of proof, along with numerous narratives concerning field tests.
The numbers are impressive. For example, according to LEC, cryogenically treated brake pads from a leading supplier generated nearly 50% more braking torque at 50kph than untreated pads, and they also provided significantly shorter stopping distances than regular brake pads at 50kph and 100kph.
Wear data on the cryogenically treated brake pads is perhaps even more interesting. According to the company, beta tests in the field by everyone from the Tempe Police Dept. to a sprint car racer and a rural mail carrier resulted in 300% to 400% improvements in the average wear life of the brake pads. On the police cruiser, for example, brake pads were routinely changed about every 6,500 miles, says Jewett. The cryogenically treated pads were replaced at 20,000 miles. Not bad.
Today, heavy-duty trucks in the United States are generally equipped with drum brakes rather than disc brakes, but that could change. "In the long run, we are convinced that the U.S. will move to disc brakes, beginning at the front axle," observes Michael von Mayenburg, senior vice president, engineering and technology for Freightliner Corp.
"Disc brakes are already the norm in Europe. Their main merit is that they don't 'fade' the way drum brakes can because the torque actually increases at high temperatures on disc brakes," he explains. "The higher cost for disc brakes is the primary issue now, and the required maintenance interval is also an obstacle," von Mayenburg adds. "Brake pads have to be replaced more often than the linings on brake drums."
Could cryogenic treatment of brake pads hasten the widespread use of disc brakes in North American trucks? Perhaps. But whatever the pace of disc brake adoption, Leading Edge Cryogenics plans to be there with its chilling technology. It's a company and a process to watch.