EFFECT OF DEEP CRYOGENIC TREATMENT ON MECHANICAL PROPERTIES OF 7075 ALUMINUM ALLOY

Aluminum alloys in various compositions displays different set of properties owing to its complex precipitation behavior during aging. Significant work has been performed by investigating the effects on various properties of ferrous metals like tool steels at cryogenic temperatures. As for Al alloys, the effects of cryogenic treatment on properties of age hardenable alloys like 7075are not reported extensively in current literature. This work consists of application of DCT at -185oC to 7075 aluminum alloy for various time durations. The cryogenic treatment was incorporated between the solutionizing and artificial aging of conventional T6 temper of Al alloy. This treatment sequence has been referred earlier in the literature for CT to 6061 Aluminum Alloy with significant improvements. The behavior of this alloy to the treatment was identified by measuring hardness, electrical conductivity and surface roughness. These measurement parameters were found to be significantly affected at specific cryogenic soaking duration and statistical analysis of experimental data supported the claim.