280 International yournal of Applied Ceramic Techmolog Vol.7,No.3,2010 Y⊕ (d) Fig. 1. Cross-sections of MI SiC/SiC specimens:( a)A/,(b)3DO-Un-R(c) 3DO-Un-Z and(d)LTLAl. The widths of the specimens are 10mm(= warp direction and y= fill direction). A high magnification image of3Do-Un-Z(e)shows some of the details of the MI microstructure proximately 50-60 mm from one another. The two aE curred in the gage section were sorted out using a sensors were synchronized, that is, both sensors would threshold voltage crossing technique"and used for record the waveform from the same event at the same analysis according to the ocala each event based time if either sensor was triggered. Events which oc- on the speed of sound of the extensional wave, whichproximately 50–60 mm from one another. The two AE sensors were synchronized, that is, both sensors would record the waveform from the same event at the same time if either sensor was triggered. Events which oc￾curred in the gage section were sorted out using a threshold voltage crossing technique17 and used for analysis according to the location of each event based on the speed of sound of the extensional wave, which Fig. 1. Cross-sections of MI SiC/SiC specimens: (a) AI-UNI, (b) 3DO-Un-R, (c) 3DO-Un-Z and (d) LTLAI. The widths of the specimens are 10 mm (X 5 warp direction and Y 5 fill direction). A high magnification image of 3DO-Un-Z (e) shows some of the details of the MI microstructure. 280 International Journal of Applied Ceramic Technology—Morscher, et al. Vol. 7, No. 3, 2010