New Wrought Heat Treatable Aluminum Alloy Based on the Al-Cu-Ca-Si System
摘要
New wrought precipitation-hardening Al-5%Cu-0.7%Ca-1.2%Si alloy has been proposed as a basis for designing a new eutectic containing material alternative to industrial high-strength 2618 alloy containing eutectic inclusions formed by Ni and Fe. The new alloy has been studied using thermodynamic calculations and experimental techniques. The obtained data suggest that the microstructure of the new alloy combines the Al-Cu aluminum matrix saturated by solutization annealing with ~ 5% Cu and Al2CaSi2-phase eutectic crystals. New alloy ingots have been subjected to hot rolling at 450°C which has yielded high-quality 2-mm-sheets. Comparative analysis of the precipitation-hardening response of the obtained sheet alloy aged at 175°C and 200°C has revealed a sufficiently high tendency to hardening which is not inferior to that of 2219-type industrial alloys. Tensile tests of the peak-aged sheet alloy have revealed a good combination of mechanical properties: ultimate tensile strength ~ 435 MPa, yield strength ~ 291 MPa, and relative elongation 15%. Thus, the new alloy can be considered promising for further studies of the effect of other conventional additions including Mn, Zr, and Fe on the tensile properties and heat resistance aimed at finalizing the alloy composition.