Nanoindentation and nanotribological behavior of Fe-N/Ti-N multilayers with different thickness of Fe-N layers

Fe-N/Ti-N magnetic multilayers with different thickness of Fe-N layers were deposited on Si (1 1 I) wafer by using magnetron sputtering technique. For comparison, Fe-N and Ti-N thin films were also prepared under the same con ditions. Microhardness and reduced modulus of the multilayer were measured by using a nanoindenter with a diamond tip in conjunction with an atomic fo rce microscope (AFM). Microfriction and microscratch tests were performed b y using a capacitance transducer with a conical diamond tip used in conjunc tion with the AFM. The results show that the thickness of Fe-N layer has ef fects on microhardness and microtribological properties of the multilayer. The microhardness of the multilayer increases with the contact depth. For a n applied normal force less than 1250 muN, the hardness of the multilayer d ecreases with the thickness of Fe-N layer, but the reduced modulus of the m ultilayer does not change much with the thickness of Fe-N layer. Friction c oefficient and microscratch scar depth of the multilayer increase with the thickness of Fe-N layer. The results indicate that the structure of Fe-N/Ti -N periodic multilayer has higher mechanical properties than single Fe-N fi lm. Among all the samples studied, Fe-N (5 nm)/Ti-N (2 nm) multilayer has t he highest microhardness, lowest friction coefficient and highest microwear resistance. (C) 2001 Elsevier Science B.V. All rights reserved.