Keyword: natural aging

  • Effect of additional alloying on stabilization of structural state and mechanical properties of industrial magnesium-rich Al-Mg alloys

    Materials Science. Non-Equilibrium Phase Transformations., Vol. 7 (2021), Issue 2, pg(s) 52-55

    Influence of small Sc, Ag, Zr, Ti, Mn addition on the stabilization of the structural state, the formation mechanisms and kinetics of the phase growth during the aging, and also technological casting properties in the industrial Al-Mg alloys were investigated. It has been established: maximum strengthening in these alloys is reached after the nature aging due to the precipitation of ordered Al3Mg phase that is isomorphic to the matrix. However, under prolonged nature aging the stable Al3Mg2 phase is precipitated in the matrix and on the grain boundary. It is accompanied by fall of the plasticity and decreasing the volume fraction of the strengthening Al3Mg phase. It is succeeded completely to prevent the formation of the stable phase under prolonged nature aging in the alloys quenched in the oi l and additional alloyed by Sc or Ag. Also Ag affects the cracking under the crystallization of alloys favorably. Using the complex of the Zr, Ti, Mn and Sc alloying elements increases the strength properties of the alloy at the quenched state slightly, but accelerates the formation of the stable phase during the nature aging.

  • The influence of natural aging and pre-aging on the mechanical, physical and microstructural properties of the EN AW-6060 aluminum alloy

    Machines. Technologies. Materials., Vol. 13 (2019), Issue 4, pg(s) 187-189

    The aim of this paper is the investigation of the effect of natural aging on the mechanical, physical and microstructural properties of an EN AW-6060 aluminum alloy. These properties were investigated during different aging treatments. Firstly, the effect of natural aging on properties was investigated, after which the influence of natural aging (room temperature pre-aging) on the artificial aging was studied. The results showed the beneficial effect of natural aging in both sets of experiment. During the natural aging, the hardness increased for around 20 % while electrical conductivity values were slightly higher than in the quenched sample. The hardness of the samples gradually increases up to 25 days of natural aging reaching a plateau state, after which the values of hardness remain the same. Also, room temperature pre-aging had a positive effect on subsequent artificial aging. Samples that were pre-aged for 40 days or more before artificial aging had around a 13 % increase in hardness values compared to the samples that were directly artificially aged. Electrical conductivity had increased by around 1 MS/m in pre-aged samples compared to only artificially aged samples. Optical microscopy investigations confirmed the existence of precipitated phases and their distribution in the microstructure.