The effect of lubricant,proosity and frequency on ultrasonic propagatin in iron PM compacts during and after compaction

摘要

Two powerful ultrasonic techniques were used to probe various iron PM compacts at different stages of production.Ultrasonic monitoring was used to follow opwder properties during the uniaxial compaction of iron powder.Non-contact laser ultrasonics was used to probe geen and sintered PM compacts.Laser ultrasonics avoids the usual need for immersion in water or the addition of a couplant,both of which may infiltrate green compact pores and distort ultrasonic measurements.