Formation of nano‐ZrO2 by laser surface treatment of ZrB2‐SiC–based composite

Abstract

AbstractThis study aims at reducing the oxidation by forming a prior‐protective‐oxide scale by laser‐surface‐treatment of two ZrB2‐SiC based composites namely ZrB2‐20v/oSiC‐2v/oB4C‐0.24v/oCf (ZSC) and ZrB2‐20v/oSiC‐2v/oB4C (ZS). ANSYS 15.0 was used to determine laser processing regime. Rigorous theoretical calculations provided temperature distribution, laser parameters and resulting laser power densities required to produce tetragonal ZrO2. Both the theoretical prediction as well as experimentation show that the laser‐surface‐treatment with the laser power densities of 31.85 and 56.61 W/mm2 for 20 and 30 s render formation of nano‐tetragonal‐ZrO2 (100–130 nm) at room temperature (RT). Morphology and size of the nano‐tetragonal‐ZrO2 grains depends on the laser exposure time. Nano‐grain size helps in stabilizing tetragonal ZrO2 phase at RT without the need of Y2O3 addition. Nano‐tetragonal‐ZrO2 may facilitate better ability for pegging, prevent scale‐spallation and act as thermal barrier coating (TBC).