The effect of pressure and pouring temperature on the porosity, microstructure, hardness and yield stress of AA2024 aluminum alloy during the squeeze casting process

The effect of pressure and pouring temperature on the microstructure, porosity, hardness and yield stress of AA2024 aluminum alloy during squeeze casting process was investigated. At a constant pouring temperature (700 degrees C), by increasing the applied pressure up to 140 MPa, the hardness increased from 125 HBN to 152 HBN while the yield stress increased from 235 MPa to 340. Moreover, by increasing the applied pressure (to 140 MPa) and reducing the pouring temperature (at 700 degrees C), the DAS size and the porosity diameter decreased to 12.5 and 0.25 p.m, respectively. Thus, the density increased to 2.75 (g/cm(3)). At a pressure of 140 MPa and 700 degrees C, an ultra-fine grain structure with an average grain size of 80 nm was observed. At squeezing pressures greater than 70 MPa, the effect of pouring temperature was less important. (C) 2017 Elsevier B.V. All rights reserved.