Thermal Stability of the Structural and Phase State of Aluminum and Alloys of the Al–Si System Doped with Zirconium Atoms under the Influence of Compression Plasma Flows

The structural and phase state of the surface layers of Al, Al-Si, and Al-Si-Cu-Mg alloys doped with zirconium atoms under the influence of compression plasma flows is studied. It is established that metastable compounds Al3Zr with the crystal structure L12 and (Al, Si)3Zr with the structure D022 are formed in the doped layers of aluminum and silumins, respectively. It is shown that doping of the studied alloys with zirconium makes it possible to increase the microhardness of the surface layer by 1.4–3 times. A study of the thermal stability of the structural and phase state of the doped layers at 550°C showed that, as a result of aluminum annealing, the Al3Zr phase with the L12 structure transforms into the Al3Zr compound with the D023 structure, and in the alloys of the Al–Si system, the decomposition of (Al,Si)3Zr and the formation of ZrSi2 occur. It is noted that the synthesized surface layer has increased temperature strength.