PT Journal AU Tillova, E Chalupova, M Kucharikova, L Svecova, I Belan, J TI Sludge Phases as Cause of Higher Wear of Cutting Tools during Machining of Secondary AlSi12Cu1 Castings SO Manufacturing Technology Journal PY 2019 BP 874 EP 879 VL 19 IS 5 DI 10.21062/ujep/387.2019/a/1213-2489/MT/19/5/874 DE Al-Si cast alloy; secondary alloys; Fe-rich phases; sludge phases; microstructure AB Present work is focused to determine the cause of higher wear of castings made of secondary (recycled) AlSi12Cu1 cast alloy after switching supplier and the morphological evolution of Fe-rich phases has been documented. As recycling of Al-alloys becomes more common, sludge will be a problem of increasing importance due to the concentration of Fe, Mn and Cr in the scrap cycle. The tendency of Al-Si-Cu alloys to form sludge Fe-rich particles can be predicted by the sludge factor (SF) equation, which represents an attempt to gather the combined effects of Fe, Mn and Cr. Sludge phases are hard and brittle phases which can compromise the machining operations, with a considerable effect on the cutting tool life, and even more degrade the mechanical and physical properties of the component. For study and identification of intermetallic phases' was utilized standard etching (Dix -Keller, H2SO4) and for element composition was used X-ray analysis. The results show that coarse sludge Fe-rich phases appear in the alloy with 0.945 wt. % Fe combined with higher content of Cr, while the Chinese script or needle-like Fe-rich phases appear combined with Mn. At the same time, a higher sludge factor was calculated and the ratio between the amount of Fe and Mn was not respected. ER