Study on microstructure and size effects of nanoindentation on membrane of antibacterial bone China

Fracture surface and surface of two kinds of membranes of antibacterial bone china with 3% and 5% composite phosphate containing rare earth were characterized by SEM and nanoindenter, respectively, and the hardness and elastic modulus was measured by nanoindenter at different load conditions. The results show that hardness and elastic modulus of the two kind of membranes have obvious size effects. Elastic modulus versus maximal depth of indentation curves are almost linear. Hardness versus maximal depth of indentation of membrane with 5% rare earth content curve is nearly linear, while that of 3% increases at first, then decreases. Obvious pile-up of indentation impression of ceramic membrane with 3% rare earth content is observed with h(f)/h(max)< 0.7 and different loads, however indentation impression of 5% has no this kind of phenomenon. Special properties of two kind of ceramic membranes are because that membranes are the mixture of crystal and non-crystal materials.