| In order to investigate the effects of Cr and Si additions in γ-TiAl alloy, the microstructure and mechanical properties before and after heat treatment were studied. Simultaneous additions of Cr and Si were more effective in stabilizing the lamellar structure of TiAl alloys after heat treatment. The stoichiometric composition of the precipitates formed in the alloy with 0.5% Si addition was estimated to be Ti_5(Si, Al)₃, and that with 3%Cr0.5%Si addition to be(Ti, Cr)_5(Si,Al)₃. Good mechanical properties could be achieved by simultaneous addition of Cr and Si. Tensile tests before and after heat treatment showed that maximum yield strength was obtained from the alloy with 1%Cr0.5%Si addition and while the highest elongation was observed by 1%Cr0.25%Si addition before heat treatment. However, the alloy with 2%Cr0.5%Si addition showed the highest elongation after heat treatment. |
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