| Abstract Scope |
The presentation focusses on the phase and microstructural evolution in laser-ignited ceramic composite based on alumina/ titanium diboride ceramic composite, in which the precursor materials are aluminium mixed with TiO2 and B2O3. The laser ignition of Al-TiO2-B2O3 mixture triggers a highly exothermic self-sustaining aluminothermic reaction (Al+TiO2+B2O3, DH= 2,736 J/kg) in the absence of atmospheric oxygen. Consequently, a ceramic phase mixture consisting of alumina and TiB2 forms spontaneously, showing a range of morphologies of phases formed.
The results of the phase microstructural analysis of the reaction products formed from the furnace-ignited and quasi-pulsed 976 nm laser-ignited (30 W maximum output) are compared. The porosity, effective density, and micro-hardness properties are compared for controlling the process parameters, namely the metallic particle size, milling time and frequency, and power density of laser for triggering the flash combustion reaction. We have also modelled the process heat flow for characterising the microstructure. |