MATERIALS EVALUATION OF PVD/CVD COATED WC/Co SUPERHARD ALLOYS BY THE ULTRASONIC MICROSCOPY

Abstract CVD/PVD coating or ion-injection processes have become one of the most important and significant key-technologies to protect surface of mechanical or electric parts or tools against various wear mechanisms and to prolong the life-time of actively working materials; TiN or other ceramic coated WC/Co is the typical tool materials to be used as the chip or die materials in the metal forming. For the optimum design of these materials and the related materials processes, new quantitative evaluation methodology is indispensable; in the present paper, the first introduction of ultrasonic microscopy oriented materials evaluation will be stated with comments on the determination of both elastic and elasto-plastic properties of TiN/TiC/Ti(CN) coated WC/Co cermets. Through discussions over the measured and evaluated elastic or elasto-plastic responses of coated cermets, the reliability of the present materials evaluation methods will be considered. KEY WORDS: PVD/CVD coated WC/Co alloyacoustic microscopyelasticityelasto-plasticityphysical modeling