Experimental Investigation and Numerical Simulation of the Grain Size Evolution during Isothermal Forging of a TC6 Alloy

摘要

Hot compression was conducted at a Thermecmaster-Z simulator, at deformation temperatures of 800~1040 deg C, with strain rates of 0.001~50 s~(-1) and height reduction of 50 percent. Grain size of the prior a phase was measured with a Leica LABOR-LUX12MFS/ST microscope to which QUANTIMET 500 software for image analysis for quantitative metallography was linked. According to the present experimental data, a constitutive relationship for a TC6 alloy and a model for grain size of the prior a phase were established based on the Arrhenius' equation and the Yada's equation, respectively. By finite element (FE) simulation, deformation distribution was determined for isothermal forging of a TC6 aerofoil blade at temperatures of 860~940 deg C and hammer velocities of 9~3000.0 mm/min. Meanwhile, the grain size of the prior a phase is simulated during isothermal forging of the TC6 aerofoil blade, by combining FE outputs with the present grain size model. The present results illustrate the grain size and its distribution in the prior a phase during the isothermal forging of the TC6 aerofoil blade. The simulated results show that the height reduction, deformation temperature, and hammer velocity have significant effects on distribution of the equivalent strain and the grain size of the prior a phase.