Boron nitride nanoplatelets induced synergetic strengthening and toughening effects on splats and their boundaries of plasma sprayed hydroxyapatite coatings

摘要: Abstract Boron nitride nanoplatelets (BNNPs) with excellent mechanical properties were introduced into HA coatings fabricated through plasma spray in this research. SEM observation and Raman results revealed the added BNNPs retained their original structure even after harsh process distributed homogeneously as-sprayed coatings. As compared monolithic coating, a 2.0 wt%BNNP/HA coating exhibited significant improvement (~ 40.3%) fracture toughness moderate enhancement 20.0%) indentation yield strength. Synergetic strengthening toughening mechanisms which are operative splat boundaries individual splats proposed. At boundaries, these embedded induced stronger adhesion between adjacent to resist sliding, is evident from fact that calculated inter-splat friction force of an BNNP/HA was increased by ~7.3% at 2.0% BNNP weight fraction. Within splats, such as pullout, crack bridging both anchored nanosized grains, deflection propagation arrested observed improve toughness. Moreover, thermal mismatch matrix during cooling would induce pre-existing dislocations formed around nanofillers, assumed hold out effect Orowan-type within splats.