In this effort, ATI will the effects of substituting or replacing all or some of the copper in 7075 with nickel and the addition of nanoparticles on the hot tearing characteristics and mechanical properties of cast material. Thermodynamic modeling will be used to develop 7075 variants and explore the phases that will form when some of all of the copper is replace by nickel. Methods such as ultrasonic dispersion will be used to mix the nanoparticles during melting and to prevent them from agglomerating. The alloy variant will be cast in the step plate mold to determine the hot tearing characteristics. Tensile specimens will be machined from the casting and tested to determine the mechanical properties. The microstructure will be examined to determine the phase content and distribution of the nanoparticles. The alloy that exhibits the optimal combination of strength, ductility and resistance to hot tearing and the processing methods will be selected for further development.
