MICHALCOVÁ Alena ICT in Prague

Recycling of Aluminium Alloys Waste into Nanocrystalline Thermally Stable Alloy

Co-authors VOJTĚCH Dalibor, NOVÁK Pavel, VODĚROVÁ Milena, ŠVEC Peter

Aluminium and it alloys are widely used structural materials. Based on both ecologic and economic reasons, it is necessary to recycle as much waste materials as possible. In case of aluminium alloys, the recycling may be complicated by presence of austenite steel in aluminium waste which is not possible to remove by magnetic separation. The presence of more then 1 wt.% of iron is highly unwanted, because it leads to formation of large irregular intermetallic particles in the recycled material. When this material with very inhomogeneous structure is processed by one of rapid solidification methods, the waste material can be transformed to very promising nanocrystalline alloy. The Al-Fe rapidly solidified alloys are known for high hardness but they usually do not have good thermal stability. This problem can be solved by adding another alloying element into the rapidly solidified system. In this work, the influence of Cr, Ni, Mn and Mm (michmetal) addition on properties of rapidly solidified alloys prepared by melt spinning method was studied. The ribbons were long term annealed at 300, 400 and 500°C and the time dependence of phase composition and hardness was described.