A NEW TECHNOLOGY FOR NANOHARDNESS MEASUREMENTS - PRINCIPLE AND APPLICATIONS

A nanoindentation device has been developed allowing the application o f forces ranging between a few micronewtons and 100 mN with nanoindent ation capabilities. The apparatus offers also very accurate positionin g in the directions through the use of a high resolution tridirectiona l piezoelectric actuator. One of the main interests of this device is its capabability to allow fast and precise measurements in normal labo ratory environment, making nanoindentation testing as simple to use as conventional hardness testing. After a short presentation of the devi ce and its working principle, some of the methods used to derive the m echanical properties of the materials are presented and illustrated by experimental curves. Interesting features, such as the micro yielding of different materials under low applied forces, are also presented. (C) 1998 Elsevier Science S.A.