What is Cryogenics?
Cryogenics is the branch of physics that deals with the production and effects of very low temperatures. Cryogenic processing is a fascinating and truly spectacular means to increase wear resistance & life on all metal and some plastics. What is cryogenic treatment? Cryogenic treatment of materials is a process for enhancing the properties of metals and crystalline or partially crystalline non-metals. Properly cryo-treat components exhibit enhanced wear resistance, increased fatigue life, somewhat improved corrosion resistance, and improved dimensional stability. How Does Deep Cryogenic Processing work? Research, some quite recent, has revealed three mechanisms at work to account for the observed property changes in components thermally cycled in a proper cryogenic treatment process. First, in hardened ferrous alloys retained austenite is transformed to martensite producing a more uniformly hard surface (and interior volume). The more uniform hardness profile is better able to resist a
In laymen terms, freezing metal parts to make them stronger. Cryogenic tempering isn’t a completely new idea. The freezing of metal in an effort to increase its durability and strength has been practiced for some thirty years within various industries. The tool and die industry regularly uses this approach to temper and extend the life of steel tooling bits. The advent of “deep cryogenics” opens new possibilities, in the case of brake rotors and brake drums. By cryo-treating a metal part, the molecular structure is made more uniform, more durable and much stronger. Cryogenic tempering changes the areas of weaker, potentially brittle deposits called “austenite” into harder, more uniform particles called “martensite”. These particles are responsible for the exceptional wear characteristics imparted by the process, due to a denser molecular structure and a reduction in porosity. In brake rotors, the process allows the rotor to absorb and sustain more heat which is the most common cause of
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Farenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One interesting feature of materials at low temperatures is that the air condenses into a liquid. The two main gases in air are oxygen and nitrogen. Liquid oxygen, “lox” for short, is used in rocket propulsion. Liquid nitrogen is used as a coolant. Helium, which is much rarer than oxygen or nitrogen, is also used as a coolant. The thermal treatment of metals must certainly be regarded as one of the most important developments of the industrial age. After more than a century, research continues into making metallic components stronger and more wear-resistant. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering. While the science of heat treatment is well known
Cryogenics is a derivative of two Greek words – “Kryos” which means cold or freezing and “genes” meaning born or one that is produced. Residual stresses exist in all types of parts from engines to tooling. The stress is introduced into the part at the time of casting, forging, heat treating or machining. These stresses create an invisible random grain pattern. Parts expand from the heat generated during operation, the retained stresses cause uneven expansion which results in increased dimensional instability with increased wear and decreased performance. Deep Cryogenic temperatures are required to effect a complete molecular change in most alloys giving the microstructure a more uniform grain structure. Deep Cryogenic temperatures distribute large quantities of very hard, fine carbides, that develop uniformly throughout the structure. Heat treatment of steel involves the transformation from its softer more malleable annealed state to a harder more durable state. This is done, as it has
