An automated microanalysis technique for measuring variations in microhardness over extended surfaces

Abstract

An analytical facility is described that is the microscopic analogue of the well-known Shore solerscope technique for measuring the dynamic hardness of macrospecimens, i.e. where a reference sphere is allowed to bounce off the test surface to determine the coefficient of restitution. In this new microapplication of the technique, a gun produces a controlled supply of charged microspheres having diameters of 0.1 – 2 μ that can be directed at a chosen test zone on a specimen of extended area. By using a drift-tube charge detector, it is possible to measure the incident and rebound velocities directly from the oscilloscope trace for each test particle, and hence the coefficient of restitution associated with each bouncing event. Alternatively, the characteristics twin-pulse drift-tube signal may be electronically digitized to provide the automated microhardness measuring system described.