Assessment of AlSi21CuNi Alloy’s Quality with Use of ATND Method

Majority of combustion engines is produced (poured) from Al-Si alloys with low thermal expansion coefficient, so called piston silumins. Hypereutectic alloys normally contain coarse, primary angular Si particles together with eutectic Si phase. The structure and mechanical properties of these alloys are highly dependent upon cooling rate, composition, modification and heat-treatment operations. In the paper one depicts use of the ATND method (thermal-voltage-derivative analysis) and regression analysis to assessment of quality of the AlSi21CuNi alloy modified with Cu-P on stage of its preparation, in aspect of obtained mechanical properties (R0,02, Rm, A5, HB). Obtained dependencies enable prediction of mechanical properties of the investigated alloy in laboratory conditions, using values of characteristic points from curves of the ATND method.