Volume 8 Issue 1 - January 2017

  • 1. Cryogenic hardening and its effect on properties of an aerospace aluminium alloy

    Authors : Sachin S S

    Pages : 566-571

    DOI : http://dx.doi.org/10.21172/1.81.074

    Keywords : Cryogenic HardeningHeat treatmentAusteniteMartensiteResidual stressCarbide particles

    Abstract :

    Cryogenic Hardening is supplementary process to conventional heat treatment process. In this process the materials are deep freeze to cryogenic temperature (below −150°C, −238°F or 123 K). It increases the strength and durability of the materials being treated, relieve stress, create a more uniform material and micro smooth surface.During the process of deep cryogenic hardening, austenite is transformed into martensite, which then tempered to change unto tempered martensite. In addition small carbide particles called eta carbides are precipitated out. This greatly reduces the residual stress and promotes the “Micro Smoothing” of the surface. There are many applications for different materials, which can be treated. The strength of the material actually increases after the process. The molecular structure is “filled-in” increases the strength of the material. Also the material will not be damaged and it will retain its shape. Cryogenic hardening is one time irreversible, permanent process. It’s a “through” process not a surface treatment which reduces the abrasive wear, relieves internal stress minimises the susceptibility to micro cracking due to shock forces, lengthens the life and increases the performance. Cryogenically treated pieces are also less susceptible to corrosion. In fact, in the case of drill bits or blades, not only the sharpness will last longer, but also be able to sharpen more times with less removal of material. Each sharpening demonstrates the benefits of hardening.

    Citing this Journal Article :

    Sachin S S, "Cryogenic hardening and its effect on properties of an aerospace aluminium alloy", https://www.ijltet.org/journal_details.php?id=910&j_id=3634, Volume 8 Issue 1 - January 2017, 566-571, #ijltetorg