The effect of the T6 heat treatment on hardness and microstructure of the en AC-AlSi12CuNiMg alloy

J. Pezda, ATH Bielsko-Biala, Faculty of Chipless Forming Technology, Bielsko-Biala, Poland Presented work discusses research results concerning the eff ect of the T6 heat treatment process, including soaking of the alloy near the solidus temperature, holding in this temperature and next cooling in cold water (20 oC), as well as exposing to the artifi cial ageing to check the change in HB hardness and microstructure of the EN AC-AlSi12CuNiMg (EN AC-48000) alloy modifi ed with strontium and cast into metal moulds. The temperature range of solutioning and ageing treatments was selected on the basis of crystallization curves recorded with the use of thermal-derivative method. Performed investigations enabled to determine the optimal parameters (temperature and time) of solutioning and ageing heat treatments and their eff ect on the change in alloy’s hardness.