Sensor probe for three:coordinate measuring machines - where probe tip is made of or coated with silicon nitride so it does not pick up workpiece material

摘要

The probe consists of a shank and a tip; and at least the surface of the tip which contacts a workpiece is made of Si3N4. The tip is pref. made of, or coated with, Si3N4; and both the tip and the shank may be made of Si3N4. When a coating of Si3N4 is used on the tip, it is pref. formed by sputtering; or a layer of Si can be sintered onto the tip and then nitrided by reaction sintering. When a monolithic shank and tip are used, they are pref. made of Si3N4 by hot pressing. Used with conventional measuring machines, it was discovered that when workpieces made of light metal were being inspected, some of the metal adhered to the tip of the probe, so erroneous results were obtd. The invention avoids such problems.