Examination of temperature distribution and the thermal effects on Si3N4 engineering ceramics during fibre laser surface treatment

Characterization and modification of technical ceramics through laser surface engineering

“…This is because the processing temperatures recorded according to the thermals study indicate that the ceramics would have undergone various phase transitions. For the Si 3 N 4 technical ceramic it can be postulated that the phase transformation of the Si 3 N 4 engineering ceramic has started to take place where a large percent of the alpha-phase is present and the beta-phase has began to form at 1400 C [59]. Around this temperature, the transition between alpha-phase to beta-phase would have occurred where alpha and beta would be found; beyond 1400 C the phase transformation of beta-phase is generally fully formed [59].…”

“…For the Si 3 N 4 technical ceramic it can be postulated that the phase transformation of the Si 3 N 4 engineering ceramic has started to take place where a large percent of the alpha-phase is present and the beta-phase has began to form at 1400 C [59]. Around this temperature, the transition between alpha-phase to beta-phase would have occurred where alpha and beta would be found; beyond 1400 C the phase transformation of beta-phase is generally fully formed [59]. Further, at 1450 C, the Si 3 N 4 fully transforms to beta-phase and shows the end of the phase transformation [59].…”

“…Around this temperature, the transition between alpha-phase to beta-phase would have occurred where alpha and beta would be found; beyond 1400 C the phase transformation of beta-phase is generally fully formed [59]. Further, at 1450 C, the Si 3 N 4 fully transforms to beta-phase and shows the end of the phase transformation [59]. Moreover, beyond 1900 C, the Si 3 N 4 technical ceramic would generally begin to decompose and vaporize [59].…”

“…Further, at 1450 C, the Si 3 N 4 fully transforms to beta-phase and shows the end of the phase transformation [59]. Moreover, beyond 1900 C, the Si 3 N 4 technical ceramic would generally begin to decompose and vaporize [59].…”

3D transient model to predict temperature and ablated areas during laser processing of metallic surfaces

“…13 Shukla and Lawrence used NX 5.0 to solve the 3D conduction equation, considering phase change. 14 Weidmann et al solved the 2D equation for calculating the temperature distribution and used the Arhenius equation to estimate the speed of ablation and predict the ablated zone. 15 Sinha solved the 2D equation and took phase changes into his model to predict the ablation zone.…”