ULTRASONIC MEASUREMENTS OF SURFACE-ROUGHNESS

Pulsed ultrasound propagating in water was used at megahertz carrier frequencies (nominally 10-50 MHz) to reflect and scatter from rough surfaces in the same way as light. We have considered noncontact ultrasonic techniques as complementary to optical techniques in several ways: (a) for specific applications such as wet surfaces, (b) for rougher surfaces with average roughness, R(a) greater-than-or-equal-to 0.1 mum, and (c) for (simultaneous) profilometry by time-of-flight measurements. Stylus and ultrasonic data are compared. An example of application to the manufacturing environment is for on-line, real-time sensor feedback and process control in the cutting or grinding of metals and ceramics.