The effect 0f heat treatments, polymer quenching and additions (Zr and Ag)‎ on mechanical properties of (6061)‎ aluminum alloy

Abstract EN

Aluminum alloys (6XXX series) are widely used in the structural components of automotive and construction industries as they show a good combination of formability, corrosion resistance, weld ability, and final mechanical properties.

The objective of this work was to introduce improve properties of 6061-T6 aluminum alloys such as impact energy, thermal age hardening behavior, thermal stability and corrosion resistance in 3.5 %NaCl solution by using quenching in 35% polyethylene glycol and addition alloying elements, i.e.

Zr with Ag together to this alloy.

And to determine the effects of artificial ageing on the properties.

The precipitation hardening usually undergoes a thermal treatments, which consists of a solution heat treatment (530ºC for 1 hour) this temperature was selected among three temperatures that used to solid solution treatment, quenching (in water, in 35 % PAG polymer solution) and artificial ageing.

The experimental study is focused on artificial ageing upon that the temperatures is varying from 160ºC- 180ºC-200ºC at different periods of time.

Several tests were carried out to evaluate the performance of alloys before and after ageing, such as Vickers hardness, impact, thermal stability (DSC), metallographic examination, corrosion resistance in 3.5%NaCl solution and X-Ray diffraction (XRD).Results showed that the hardness of the base alloy (A) as homogenized was 48.7(kg /) whereas to alloy with additions from (Zr and Ag)(B) alloy was 50.7, the hardness at solid solution treatment was in alloy that quenched in water higher than these quenched in polymer Addition of 0.03 % Zr with 0.18 % Ag to the base alloy improves thermal age hardening behavior by (17.3 %) when quenching in water, and by (17.1 %) when quenching in 35 %PAG at ageing temperature 180 in comparison to the base alloy.

The addition of 0.03 % Zr with 0.18 % Ag together to base alloy improves impact energy by (25 %) when quenching in 35 %PAG corresponding to the base alloy when aging at 180 ºC From DSC curves could conclude the alloys that quenched in polymer solution have been higher thermal stability than these quenched in water.

An improvement of corrosion resistance in 3.5 % NaCl solution when the alloys quenched in polymer solution have been higher corrosion resistance than these quenched in water at aging temperature 180ºC.