Effects of high power ultrasonic vibration on the cold compaction of titanium

- Cold compaction of titanium powders under superimposed high power ultrasonic are investigated.
- The density of compacts up to 7.53% is increased.
- Friction stress reduction up to 88.5% is observed.
- Reduction of spring back is measured up to 8.8% in fine powders.

Titanium has widely been used in chemical and aerospace industries. In order to overcome the drawbacks of cold compaction of titanium, the process was assisted by an ultrasonic vibration system. For this purpose, a uniaxial ultrasonic assisted cold powder compaction system was designed and fabricated. The process variables were powder size, compaction pressure and initial powder compact thickness. Density, friction force, ejection force and spring back of the fabricated samples were measured and studied. The density was observed to improve under the action of ultrasonic vibration. Fine size powders showed better results of consolidation while using ultrasonic vibration. Under the ultrasonic action, it is thought that the friction forces between the die walls and the particles and those friction forces among the powder particles are reduced. Spring back and ejection force didn't considerably change when using ultrasonic vibration.