NON DESTRUCTIVE EVALUATION OF CERAMIC BEARINGS

RESONANT ULTRASOUND INSPECTION CAN RAPIDLY FIND CRACKS FLAWS AND TOLERANCE ERRORS IN SOLID STRUCTURES. IN METALLIC BEARINGS, WE HAVE MEASURED SPHERICITY TO 50PPM (.0002 MM IN .5 CM BEARING) AND, IN ADDITION, WERE ABLE TO DETERMINE THE PRESENCE OF FLAWS WITH THE SAME SENSITIVITY. RECENT TESTS BY LANL, USING A JOINT LANL/QUATRO PATENT DISCLOSURE, HAVE INCREASED THIS SENSITIVITY SEVERALFOLD, HOWEVER, THESE RESULTS HAVE NOT BEEN QUANTIFIED. THIS CONCEPT UTILIZES THE DETECTION OF HARMONIC COMPARISONS IN BOTH THE DRY AND SOLVENT WETTED CONDITIONS. QUATRO WILL APPLY THIS TECHNIQUE TO CERAMIC BEARINGS BY SUBJECTING THE SUBSTRATE TO A BROAD SPECTRUM ACOUSTIC SIGNAL AND EXAMINING THE RESULTANT HARMONIC RESONANCES. OUR INSTRUMENTATION WILL THEN SUBTRACT THE SPECTRA TO DETERMINE THE PRESENCE OF FLAWS. THE OBJECTIVE OF THIS PROPOSAL IS TO DEVELOP A PROCESS, INCLUDING THE SOFTWARE, HARDWARE AND PROCEDURES BY WHICH A CERAMIC BEARING MAY HAVE ITS SPECTRUM TAKEN WITHIN 1 SECOND. THIS WILL THEN BE DEVELOPED INTO AN ACCEPTANCE TEST TO SELECT QUALIFIED BEARINGS. TO DETERMINE MANUFACTURING TOLERANCE LIMITS AND NON DESTRUCTIVE DETECTION OF STRESS OR CORROSION INDUCED CRACKS AND FLAWS. THIS TECHNIQUE SHOULD BE LESS EXPENSIVE, FASTER, PORTABLE AND MORE VERSITILE THAN PULSE ECHO, FLUORESCENT DYE PENETRANT, MAGNETIC PARTICLE AND EDDY CURRENT TECHNIQUES. RESONANT ULTRASOUND INSPECTION DETECTS FLAWS ON INACCESSABLE INTERNAL SURFACES.