Металознавство та обробка металів (Mar 2020)

The influence of technological factors on the properties of high-strength aluminum alloy of the Al-Zn-Mg-Cu system

  • Verkhovliuk Anatoliy M. ,
  • Shcheretskyi Alexander A. ,
  • Kanibolotsky D.S. ,
  • Dovbenko V.V.

DOI
https://doi.org/10.15407/mom2020.01.027
Journal volume & issue
Vol. 26, no. 1
pp. 27 – 36

Abstract

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Thermodynamic calculations were carried out and technological phase diagrams of the Al-Zn-Mg-Cu system alloy were constructed with the minimum, maximum concentrations of alloying elements and with the maximum possible impurity content. It was found that the S phase (Al2CuMg) is released at the maximum content of alloying elements in the alloy, which increases the hot cracks formation likelihood. The effect of zinc, which was added to the melt in various ways, on the structure and properties of the Al-Mg-Cu system alloy, is investigated. It has been shown that the superheat temperature and zinc concentration essentially affect the structure and hardness of the alloy. The grain size increases about three times when the melt is overheated to 1100 ºС or 1150 ºС compared to overheating to 750 ºС. In contrast, the dendrite parameter decreases with overheating, although not significantly. When the melt is heated to a temperature of 1150 ºС, the size of the dendritic parameter decreases by 1.16 and 1.47 times in the cast samples into which zinc was introduced by ligature and bell, respectively. The size of the dendrite cell of the cast sample is approximately 25 microns if zinc has been introduced in a vapor state into not overheated melt at 650 ° C using a reactor, and the cell size is slightly reduced by 1.1 times to 23 microns, when the melt overheats to 1100 ° C.

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