Design of As-Cast High Strength Al-Si-Cu-Ni-Sr Alloys Using the Taguchi Method 2017-01-5009

In the present study, a design of experiment (DOE) technique, the Taguchi method, was used to develop as-cast high strength aluminum alloys with element additions of Si, Cu, Ni and Sr. The Taguchi method uses a special design of orthogonal arrays to study all the designed factors with a minimum of experiments at a relatively low cost. The element factors chosen for this study were Si, Cu, Ni and Sr content in the designed aluminum-based alloys. For each factor, three different levels of weight percentages were selected (Si: 6, 9, 12%, Cu: 3, 5, 7%, Ni: 0.5, 1, 1.5% and Sr: 0.01, 0.02, 0.03%). Tensile properties such as ultimate tensile strength, yield strength and elongation at failure were selected as three individual responses to evaluate the engineering performance of the designed alloys. The results of the factor response analysis were used to derive the optimal level combinations. The alloy with the optimal composition had an average UTS of 267.00 MPa, an elongation at failure of 1.13% and a yield strength of 210.37 MPa under the as-cast condition for a squeeze casting with a section thickness of 25 mm. The contribution of each factor was determined by an analysis of variance.