Effect of T6 heat treatment on mechanical properties and microstructure of EN AB-42000 alloy modified with strontium

Process of silumin properties perfection in scope of classic (simple and cheap) methods is connected with change of morphology of silumin precipitations through: process of alloy modification, maintaining suitable temperature of superheating treatment and pouring into moulds, as well as perfection of heat treatment operations. In the paper are presented results of a tests aimed at investigation of an effects of performed heat treatment operations on change of tensile strength of EN AC-42000 silumin modified with strontium. Investigated alloy was melted in electric resistance furnace. Course of crystallization process was recorded with use of thermal-derivative analysis (ATD), and on base of this analysis one determined temperatures range of heat treatment operations of the alloy. Performed heat treatment operation resulted in change of mechanical properties (Rm, A5) of the investigated alloy, whereas performed tests enabled determination of temperature and duration of solutioning and ageing treatments, which condition improvement of its mechanical properties.