Estudo da influência da vibração em ligas de Al-Cu

Abstract

Aluminum has been extensively used because of its excellent cost-benefit ratio, as well as being a highly recyclable metal. These factors lead to a significant number of studies to optimize their mechanical properties from their processing. One of these studies refers to the application of vibration during its solidification. For the most part, it is possible to obtain a more refined microstructure, with smaller volumes of porosity, when the optimal points of vibration are found. The objective of this work is to perform a study on the effect of the application of the vibration in Al-Cu alloys, with variations in the copper contents, during the solidification in a metallic mold. The relationship between Chvorinov's modulus and the intensity of applied vibration was also studied. The casting was carried out at 720 ºC in pre-heated Y-type 300 ° C, with a subsequent thermal treatment of solubilization and T6 precipitation. The mold was positioned on a stand where the turbine pneumatic vibration device model GT-10 from the manufacturer MVL was coupled. Pressures of 0.5 bar; 1 bar and 1.5 bar, were applied and another sample without vibration. Tension tests were performed according to the B557M-10 standard. Other characterization methods were HRF hardness, HV microhardness, density determination, chemical analysis and metallography. About hardness, alloys with higher Cu contents presented higher values of hardness, regardless of the applied vibration. For the tension test, the alloy with 1.9% Cu with the application of 1 bar of pressure obtained the highest value for tensile strength (200 MPa) and the highest ductility with 8.7% elongation. Regarding the variation of the modulus, the application of the vibration was only valid for the higher copper contents.