Synthesis of Al3Zr precipitates in aluminium and its alloy by means of compression plasma flows

Abstract

Small additions of zirconium can significantly improve mechanical properties of aluminium alloys due to the formation of an intermetallic compound Al3Zr. This compound has a stable tetragonal D0 23 structure and a metastable cubic L1 2 structure [1]. However, in [2] it was shown that metastable Al3Zr with a tetragonal D0 22 structure could also be formed. A high cooling rate during crystallization of the alloy and the presence of alloying elements stabilizing D0 22 structure can be the main reasons for its formation. The previous investigations have shown that compression plasma flows (CPF) can be effectively used for mixing of a “coating/substrate” system, thus leading to alloying of a substrate at a depth of tens of micrometers with atoms of coatings [3-4]. This approach is used in the present work to form composite surface layers containing Al 3Zr precipitates in aluminum and an aluminum based alloy.