Energy Dissipation Dynamics in Bulged Profiles in Sinter Forging

Abstract

This paper explores various aspects of bulging in high-speed sinter-forging across different relative densities. The forging process of sintered preforms involves significant energy dissipation, affected by factors like die speed, bulging coefficient, initial relative density, and height reduction. High die speed results in increased frictional energy dissipation, leading to surface heating and bulging. Moreover, there is a notable increase in energy dissipation, die load, and frictional energy with a reduction in height, primarily dissipating heat on the preform surface. Total energy dissipation, die load, and frictional energy notably increase with die speed, particularly with higher bulging coefficients and initial relative densities. Additionally, inertial energy dissipation rises rapidly under these conditions. The intricate relationship between fractional internal energy dissipation and fractional frictional energy dissipation to total energy dissipation highlights the complexity of the process, with internal energy dissipation decreasing while the frictional energy dissipation component increases with bulging coefficient and relative density. At high die velocities, most energy dissipates as frictional heat, underscoring the need to control forging velocity for desired product outcomes.