Indentation induced testing studies on lanthanum modified lead titanate ceramics

Results of indentation induced Vicker’s microhardness, internal stress, and fracture toughness studies in the load range of 0.1–10 N on lanthanum modified lead titanate (PT) ceramics bearing composition Pb1−xLaxTi0.96Fe0.02Mo0.02O3, where x=0.02, 0.05, 0.10, 0.15, and 0.20 are presented. The load dependence of Vicker’s hardness number (VHN) is explained on the basis of Hays and Kendall’s law. Load independent value of VHN is worked out by the application of Hays and Kendall’s law for different compositions of lanthanum modified ceramics and the same is shown to increase with the increase in lanthanum substitution. Internal stress, fracture toughness, and brittleness index for these samples have also been calculated using microindentation technique.