VLACH Martin Univerzita Karlova v Praze

Spoluautoři STULÍKOVÁ Ivana, SMOLA Bohumil, KUDRNOVÁ Hana, KEKULE Tomáš, MÁLEK Jaroslav, OČENÁŠEK Vladivoj, TANPRAYOON Dhritti and NEUBERT Volkmar

The conference paper reports results of a study aimed at understanding precipitation processes of the binary Al–Mn and quaternary Al–Mn–Sc–Zr alloy. The alloys were investigated in the as-cast state and cold-rolled state. The alloys were studied during isothermal annealing at 300, 400, 500 °C and 550 °C and during step-by-step quasilinear annealing from room temperature up to 600 °C with heating rate 100 K/h followed by subsequent isothermal annealing at 600 °C/5 h. The effect of the pseudo-homogenization heat treatment (610 °C/18 h) on phase transformation in the studied alloys was also investigated. Precipitation reactions were studied by electrical resistometry, conductivity and (micro)hardness measurements. The microstructure development was investigated by transmission and scanning electron microscopy, electron diffraction and electron backscatter diffraction examinations. The hardening effect is due to fine, coherent, uniformly distributed Al3Sc and/or Al3(Sc,Zr) particles. The distinct changes in resistivity and conductivity of the cold-rolled alloys at temperature above 300 °C are mainly caused by precipitation of Mn-containing particles. Precipitation of these particles has an insignificant effect on microhardness.