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In‐situ surface absorptivity prediction during 1.06 μm wavelength laser low aspect ratio machining of structural ceramics
Author(s) -
Samant Anoop N.,
Du Baoshuai,
Dahotre Narendra B.
Publication year - 2009
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200925108
Subject(s) - molar absorptivity , materials science , ceramic , thermocouple , machining , silicon carbide , laser , silicon nitride , wavelength , carbide , optics , silicon , analytical chemistry (journal) , composite material , optoelectronics , metallurgy , chemistry , physics , chromatography
Abstract This study predicts the variation of surface absorptivity with temperature for structural ceramics such as magnesia (MgO), alumina (Al 2 O 3 ), silicon nitride (Si 3 N 4 ), and silicon carbide (SiC). In‐situ temperatures reached during pulsed 1.06 μm Nd:YAG laser low aspect ratio cavity machining of the ceramics under various number of pulses were sensed by a K‐type thermocouple. A thermal model was calibrated by varying the absorptivity to match the computed temperature to that with the measured temperature in the ranges of 860–980 K (MgO), 1020–1120 K (Al 2 O 3 ), 900–1150 K (Si 3 N 4 ), and 700–950 K (SiC) at a given distance from center of the laser beam. Such absorptivity predictions are critical for accurate predictions of suitable machining parameters and in determining actual energy absorbed during low aspect ratio laser machining of structural ceramics. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)