Numerical Simulation Of Zr-Based Bulk Amorphous Alloys During Casting Solidification Process

With the outer ring of the bearing for 29320 type self-aligning roller as a model component, the casting process of Zr41Ti14Cu12.5Ni10Be22.5 bulk amorphous alloy is studied by the method of numerical simulation. Through application of large-scale general-purpose finite element analysis software ANSYS, under the control equation of incompressible viscous fluid and the standard k ?εmodel, the transient flow field, temperature field and stress field in three-dimensional finite element model, as well as the treatment of initial conditions, boundary conditions, latent heat of the mathematical model are established, the flow field during melt filling, temperature field and stress field during solidification are simulated. The velocity distribution and flow patterns in the cavity are analysed, velocity vector, temperature field distribution contour in the process of liquid filling and temperature field distribution contour, temperature gradient and stress distribution contour in the process of casting solidification are acquired.In the simulation, the temperarure of both the casting and the mould is considered as the initial condition for the following solidification, replacing the previous assumption that the initial temperature of solidification process is the pouring temperature, so that the final accuracy of the simulation is improved.The simulation results of solidification process show that: approximately in 13 seconds, the temperature of alloy melt decreased to the melting point (Tm=663°C), and in 25 seconds, the temperature of alloy melt reached the glass transition temperature (Tg =360°C). The average cooling rate in this period is 29.4°C/s. When the temperature of melt reduced to the glass transition temperature, the instantaneous cooling rate is 15.8°C/s, which is far greater than the critical cooling rate of Zr41Ti14Cu12.5Ni10Be22.5 alloy.