Characteristic Analysis Of The Stress Propagation Of Metal Powder In High Velocity Compaction Using Dem

Loading during the high velocity compaction (HVC) of metal powder generates high-speed impact. Thus, the dynamic stress of the powder rapidly changes, and its propagation properties exert an important influence on powder densification. In this investigation, the progress of HVC is simulated using a discrete element method, and stress propagation is characterized by the distribution and variation of the Y-direction stress along the height direction. The influences of impact velocity, initial porosity, and friction coefficient on stress propagation velocity are analyzed. Results show that stress in HVC represents the upper and lower reciprocating propagations. Moreover, stress concentration corresponds to low porosity. With an increase in impact velocities, the forward and opposite propagation velocities both increase. With an increase in initial porosities, the forward propagation velocity decreases remarkably, but the opposite propagation velocity decreases only slightly. With an increase in friction coefficients, the forward propagation velocity increases substantially, but the opposite propagation velocity increases only minimally.