The effects of strontium and grain refiner additions on the fatigue and tensile properties of industrial Al-Si-Cu-Mg alloy castings produced using the Ford Motor Company—Cosworth precision sand process

Tensile and fatigue properties of production cylinder block castings are reported. The alloy used is aluminium association alloy 320, an Al-Si-Cu-Mg alloy that has found common use in cylinder block and cylinder head applications. Trials involving modification using strontium and grain refinement using a titanium-boron master alloy were conducted. The effects of these additions on amount of porosity, maximum pore size, tensile properties and mean fatigue strength as well as the novel application of grain refiner are discussed. Grain refinement was found to be of marginal benefit, while strontium additions showed pronounced negative effects on the properties studied.