[SY-M2] Multi-scale modelling of Zener Pinning during the solid solution treatment of a Nickel-based Superalloy
The ability to manufacture components to provide location specific properties is needed to improve component performance, increase component life and reduce cost. In Ni-base superalloys, the grain size and the strengthening precipitate dispersion have a large impact upon creep and fatigue behaviour. It is possible to obtain dual microstructures across turbine discs through careful design of the solid solution treatment process, optimising mechanical properties where needed.
A simulation tool has been developed to assist in the design of such heat treatments, modelling grain growth with Zener pinning precipitates that evolve during thermal processing. The work focuses on modelling grain growth in the Ni-based Superalloy RR1000, containing a tri-modal γ’ particle dispersion where the largest particles pin grain boundary movement. A multi-scale approach has been developed to capture the evolution of the precipitates, using a statistical approach to capture the kinetics of the secondary and tertiary particle populations.
The grain growth is described using a two-dimensional model, including the evolution of primary γ’ precipitates. The level-set method is used to model the grain boundaries and precipitate-matrix interfaces implicitly. A multi-component mean-field description has been applied to simulate the kinetics of the precipitates. A morphologically explicit mean-field growth rate has been developed to describe the kinetics of the primary particles, consistent with the description of the secondary and tertiary particles.
The proposed model shows good potential in capturing grain growth kinetics and may serve as a useful tool for simulating solid solution treatments in multi-modal nickel-based superalloys.
A simulation tool has been developed to assist in the design of such heat treatments, modelling grain growth with Zener pinning precipitates that evolve during thermal processing. The work focuses on modelling grain growth in the Ni-based Superalloy RR1000, containing a tri-modal γ’ particle dispersion where the largest particles pin grain boundary movement. A multi-scale approach has been developed to capture the evolution of the precipitates, using a statistical approach to capture the kinetics of the secondary and tertiary particle populations.
The grain growth is described using a two-dimensional model, including the evolution of primary γ’ precipitates. The level-set method is used to model the grain boundaries and precipitate-matrix interfaces implicitly. A multi-component mean-field description has been applied to simulate the kinetics of the precipitates. A morphologically explicit mean-field growth rate has been developed to describe the kinetics of the primary particles, consistent with the description of the secondary and tertiary particles.
The proposed model shows good potential in capturing grain growth kinetics and may serve as a useful tool for simulating solid solution treatments in multi-modal nickel-based superalloys.