ultrasonic assisted cold compaction of cp titanium and ti-6al-4v alloy

Superimposed ultrasonic vibration during compaction of commercially pure (cp) titanium and ti-6al-4v alloy improves the relative density and quality of the compact. the underlying mechanisms of this process are not well understood. in this study, the influence of ultrasonic vibrations on the densification behavior of square packing of ti-6al-4v and cp-ti powders during cold compaction was investigated using the multi-particle finite element method (mpfem). acoustic softening and friction reduction were introduced in this model. the density-pressure curves show that ultrasonic vibration improves the densification of these powders, owing to the acoustic softening that leads to a decline in the required pressure. it has been found that the ultrasonic effect on reducing the compaction pressure and stress in the case of pure titanium is greater than that of titanium alloy. in addition, an increase in the intensity and amplitude of ultrasonic vibration reduces stress. the rotation and rearrangement of the particles caused by the reduction of friction lead to an enhancement in the compression capability.