A Brief History of Deep Cryogenic Treatment
About the Name "Deep Cryogenic Treatment
This process was originally called "Cryogenic Treatment" or "Cryogenic Processing". Somewhere along the line it picked up the incorrect name of "Cryogenic Tempering." The scientific community almost universally is now using the term "Deep Cryogenic Treatment" and we have decided to align ourselves with that term. You will see us using the other names for SEO reasons.
The history of Deep Cryogenic Treatment began with the cold treatments—or sub-zero—treatments of the past, which have been around for quite some time. There are stories of Swiss watchmakers burying newly made parts in snow, and it is well known that companies would “age” castings by putting them outside during the winter.
Engine maker Pierce-Arrow, having definite advantage in the technology by being in Buffalo, New York, where it is known to get quite cold, used this cold treatment aging method for their engine blocks. Indy car builders have told us their fathers would age castings in a similar manner before using them to make racecar engines. In a similar manner, racer Jim Birks, found engines which sat in junk yards through several winters made superior race engines compared to brand new engine blocks. That is what caused him to look into the use of cold for making metals last longer. He found the existing research on the subject, which led him to help start Controlled Thermal Processing.
We’ve traced the history of cryogenic treatment as far back as the 1930s, when the Junkers Company in Germany used it on for military airplane components. According to ex-Junkers engineer Adolph Luerker, who immigrated to the US after the war, it was a vital part of the engineering that went into their reliable Jumo 1,000 HP V-12 aircraft engine. When he ended up in California working for McCulloch Chain Saw Company in the mid 1950s, he suggested they use the process on chain saw blade links. They started cryogenically treating their chainsaw blades but kept it a secret so other manufacturers could not make better blades.
The United States enters the history of cryogenics at the Watertown Arsenal in Watertown, Massachusetts, during World War II under the guidance of Clarence Zener, who would go on to develop the Zener diode among other advances in solid-state physics. The method was straightforward. Steel cutting tools were immersed in liquid nitrogen for a brief period of time, then removed from the liquid, allowed to warm up, and placed into service in the arsenal’s production lines. Occasionally tools would crack or chip as a result of the thermal shock associated with the rapid rate of cooling. Some tools also became brittle because of the newly formed, un-tempered martensite and chipped in service. Of the tools that survived this crude quenching, many exhibited dramatically enhanced service life.
Similar processes have been claimed across several industries from the 1940s onward. This “throw and go” approach to cryogenics relied on hoping for the best, with understandably mixed results. You don’t begin to see the stirrings of actual scientific refinement until a magazine article from the July 1957 edition of Tooling and Production Magazine. Cryogenics began to garner attention.
As interest grew in cryogenics, several people emerged as driving forces in cryogenics research in the early 1970’s. The most notable and persistent was Dr. Randall Barron of Louisiana Technical University, who wrote multiple research papers about the subject, as did some of his students. These papers are widely cited in the cryogenics industry even today.
Another early pioneer in the industry is Dr. Hugh E. Trucks, a design specialist at General Dynamics Corporation and later a private consultant. He wrote several articles on the subject, notably one for the Die Casting Engineer edition of September/October 1988. Dr Trucks was also affiliated with Cryogenics International, of Scottsdale Arizona.
A third pioneer is Ed Busch, who founded Cryo-Tech, Inc., who has been preaching the industrial use of cryogenics for over 30 years. He found the process hard to sell to industries that had never heard of it. He was also an important force in making the process available to industry. Cryo-Tech was eventually bought out by 300 Below, an industry competitor who we had processed parts for during their early days.
The Development Of True Cryogenics
Several things had to come together to make any invention work well. When speaking of the history of cryogenics, four key elements were necessary:
A way to create and sustain extremely cold temperatures needed to be discovered.
A process had to be established to control the temperature of the cold chamber in a reproducible manner.
There had to be a realization that beneficial changes could occur even at very cold temperatures.
The change had to be tested. This involved having a means of testing and being able to eliminate the possibility of other random changes in the process.
It is obvious that the process could not exist even on an experimental basis until it was possible to achieve temperatures that were considerably colder than the Earth’s climate allowed. A good history of cold can be seen on the PBS series Nova.
Some documentation shows that artificial refrigeration occurred at the University of Glasgow in 1748. William Cullen’s work relied on the vapor-compression refrigeration process explained by Michael Faraday. It was not until 1845 that refrigeration units became available, driven by the need for a cure for malaria. Doctor John Gorrie felt that malaria was the result of bad air, and if he could condition the air, malaria would not occur. While he was incorrect about malaria, he did advance the art of cooling by designing an apparatus to produce ice.
The discovery by Louis-Paul Cailletet in 1877 that gasses could be cooled by sudden expansion and the discovery by Marc-Auguste Pictet of the cascade cooling method led to Sir James Dewar’s research, which then led to the discovery that air could be liquefied and stored in the eponymous Dewar flasks. While different processes were investigated until the late 19th century, Carl von Linde’s invention of a continuous process of liquefying gases in large quantities formed a basis for today’s refrigeration technology. The almost simultaneous invention of air liquefaction processes in Britain, Germany, France and the United States around 1895 led to the production of liquid gasses in quantity.
The science of refrigeration had to develop before the process could go ahead. It was not until the mid 1930’s that refrigeration got to the point where economical quantities of liquid oxygen could be made. For a long time, the liquid nitrogen, which was a byproduct of the liquid oxygen production, was simply vented to the atmosphere.
The second innovation needed for the history of cryogenics to progress was the invention of a mechanism and process that would allow the controlled cooling of a part in a repeatable manner. It is not enough to simply reduce temperatures. They must be held in the desired range before being warmed back up in a slow, controlled process. This tended to be expensive and cumbersome before microprocessor controls became available.
It was the invention of the microprocessor controlled temperature control unit really made it possible to get precise, repeatable results in cryogenic processing. By combining electronic control with advancements in insulation, the ability to explore the potential of cryogenics was in reach.
A Cognitive Leap
One condition you see throughout the history of cryogenics that hindered progress was that, intuitively, one would not think of materials changing due to cold. After all, you heat treat metals, with the emphasis on heat. Archeological evidence shows that humans have been using heat on metals for over 7500 years. Extreme cold has only been available for roughly 100 years. It is ingrained in our culture that you use heat to change metals not cold, yet even the most basic texts on metallurgy describe the temperature dependence of heat fails to fix defects in the crystal structure of metals.
The common belief is that cold tends to inhibit chemical reactions, not promote them. While that may be true in some cases, with ferrous metals, we know at colder temperatures you can get austenite to change to martensite crystals. That’s why it is not unusual for companies to “season” castings for about a year or so before machining them by leaving them outside over the winter. The theory at the time was that the change was more associated with time than temperature, and most likely the original reason for putting them outside was because there was no room to keep them in the production space.
If you are resistant to the idea that cold can make things happen, consider this: Super conductivity is created by cold; it is undeniable that something changes at near Absolute Zero temperatures which cause metals and ceramics to behave differently.
Putting It To The Test
In order to make people think in terms of cold temperatures improving things, the changes had to be detectable. Even into the 1940’s measurements were not precise enough to indicate the changes we now know were caused by cryogenics. Processes were not controlled well enough to be able to say with certainty the change was a direct result of the cold. A cutting tool may have lasted twice as long, but that was easily attributed to the effects of how it was ground or the variance in cutting geometry. Given that there could be large differences between the process used from one piece and another, the benefits given by the process could always be attributed to the production differences.
Once Doctor W. Edwards Deming taught us to control our processes closely, we began to be able to detect other things that could drastically change the production process. This is a common roadblock to advancement even today. Even after testing, some people have problems making the adjustment to the concept of cold as a force of change.
Learning Through Experience
It is important to realize that throughout much of the history of cryogenics, this process has been largely empirically developed. Large corporations and government bodies, often the largest funding sources for scientific exploration, have been slow to study the how of cryogenics. Even Dr. Barron’s published works go largely to the results of the process rather than how the process works. As Dr. Levine of Applied Cryogenics, Inc. in an article written in August 1998, says, “We just were not knowledgeable enough to realize that it couldn’t possibly work, so we worked with it and found that it did work.” The process is in need of research to optimize its results.
Deep Cryogenic Treatment Today
ASM International, the professional society of metallurgists and materials scientists, started a committee on the deep cryogenic process in the late 1990’s. This committee was founded when members started to complain about the outlandish claims made by some of the early companies that formed to promote the process. Claims such as, “No one has ever blown up a cryogenically treated engine,” and, “cryogenic treatment increases the strength of steel by ten times,” did a lot of harm to the truth that surrounds the cryogenic process. The committee also wanted to create a database of research and articles about cryogenics, and promoted sessions at ASM conferences that featured cryogenic processing.
About the same time that ASM got into the act the Cryogenic Society of America stepped up to the plate. They have been a great help in publicizing the process in their house magazine Cold Facts, in directing companies towards responsible cryogenic processors, and in debunking outlandish claims. The Cryogenic Society of America worked with members of the ASM committee and created the database of articles and research papers regarding Deep Cryogenic Treatment. It is available to the general public at www.cryogenictreatmentdatabase.org. Both CSA and ASM have been very important factors in restoring the public confidence in this wonderful process.
Contact CTP Today
We look forward to the advancements we’ll see in the field of cryogenics and are proud to be a guiding force in the further development of cryogenic science and its commercial applications. If you’re ready to make your company part of the history of cryogenics, contact our cryogenic specialists today.
Controlled Thermal Processing is proud to work with researchers from such institutions as Illinois Institute of Technology, the US Army, Los Alamos National Laboratory, Honeywell, and others. We have also helped by supporting research on the high school and grade school level. We will consider providing cryogenic processing for any valid research project.