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This work is motivated by the fact that the microstructures of nickel-based alloy forged parts influenced by hot deformation have a great impact on the mechanical properties of their final parts. In this paper, a simplified 2D half-symmetry FE model embedded with the JMAK model is developed to predict the deformation characteristics and microstructure behaviors of an IN718 aeroengine drum in hot forging procedure and then verified by experiments. Moreover, based on two evaluation indexes, the distribution uniformities and general levels of effective strain, strain rate, temperature, dynamic recrystallization, and grain size within the forged IN718 alloy drum are analyzed quantitatively. The results suggest that unlike strain rate and grain size, the maximum values of effective strain, temperature, and dynamic recrystallization volume fraction are located at the internal wall of the forged drum, and their distribution uniformities become worse with the increment of forging strokes. Besides, the Xavg and davg show an opposite evolution trend as increasing forging strokes, which are mainly related to the increments of εavg and Tavg as well as the grain refinement of dynamic recrystallization. [ABSTRACT FROM AUTHOR]

This study is prompted by the reality that the forging velocity greatly impacts the phase transformation of titanium forged parts, further affecting the ultimate microstructures and mechanical properties of their final parts. In this paper, to predict the transformation characteristics of temperature and phases in Ti-6Al-4V drum hot forging procedure, a simplified FE model embedded with phase transformation equations is developed and verified by experiments. Then, based on two evaluation indexes, the effect of forging velocity on the transformation characteristics of temperature and phases within the forged drum is analyzed quantitatively. The results suggest that unlike little effect on lamellar α+β phase, appropriately enhancing the forging velocity can increase the general levels of temperature and β phase and improve the uniformities of temperature, α phase, and β phase distributions within the forged drum. [ABSTRACT FROM AUTHOR]

In this paper, the entity-connector and non-entity-connector of design feature are defined and the connector is divided into two classes. The P/T net-based hierarchy structure model of the component-connector design feature and the energy flowing P/T net model of the primitive mechanism are built up. The product model is mathematically described from the perspectives of the function, design feature, attribute and their relationships. Then the P/T net-based hierarchy structural model is applied to represent the conceptual product, and the energy flowing P/T net is established to simulate the working status of the conceptual product. [ABSTRACT FROM AUTHOR]