NOVEL NANOINDENTATION METHOD FOR CHARACTERIZING MULTIPHASE MATERIALS

We present the nano-hardness tester (NHT), a new depth-sensing instrum ent with a differential capacitive sensor providing nanometer depth re solution and allowing partial elimination of the frame compliance. Wit h micron lateral positioning of the sample and topographical measureme nt of the residual indent, using scanning force microscopy, it is poss ible to gain a better understanding of the indentation method and its effects on the material being tested. Furthermore, parallel imaging al lows the material response to be directly investigated. Experimental r esults are presented for a selection of aged austeno-ferritic stainles s steels; these confirm the ability of the NHT to become a common test instrument in quality assurance and process development of multiphase materials. (C) 1997 Elsevier Science S.A.