Ravishankar Angal
Published: 2005
Total Pages: 206
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Abstract: Quantitative simulations of solute redistribution during solution treatment of cast alloys require an interdiffusion database consisting of diffusivities for all major alloying elements as function of temperature and composition. For Al alloy 319, diffusivities for Cu and Si are needed within the primary phase field of the aluminum rich corner of AI-Cu-Si phase diagram, since it is the aluminum rich phase were most diffusion occurs during heat treatment. The purpose of this work is to verify the diffusivity of Cu and Si in single phase [alpha] region with the available literature tracer diffusivity values and also study the effect of the Mg on the diffusivity of the Cu and Si. Effect of the silicon phase particles on the diffusivity of Cu was also studied in two phase, [alpha] + Si phase alloys. Diffusion alloys were made from master alloys and were annealed from temperature 450 - 540 0C for 72 to 144 hrs. Concentration profiles for Cu and Si were measured by electron probe micro analysis and diffusion coefficients were calculated by using probability paper plots. It was found that the diffusivity of Cu and Si in single phase [alpha] diffusion alloys increases with increase in Mg content. Cu diffusivities in two phase, [alpha] + Si phase increases with increase in surface area to total volume ratio, Sv of the silicon particles.