R. Naslain et al/Composites: Part A 30(1999)537-547 fixed epoXy mini SiC CVD calibrated 000 masses switches Fig. 3. Mechanical testing of micro/minicomposites: (a) tensile specimens; (b) tensile device for minicomposite tests; and (c) apparatus for lifetime urements in air at high temperatures of SiC/SiC microcomposites, according to Ref. [ 9, 12, 26] interphases with elementary layer thicknesses of a few nm Vr=0.50, corresponding to that commonly observed for the can only be deposited (infiltrated) in a controlled manner by corresponding real nD-composites). The chemical analysis P-CVD/P-CVI [22, 23]. In a last step, the Sic (or carbon) of the FM-interfacial zone was performed according to two was deposited (infiltrated) by conventional CVD complementary techniques: (i) by Auger electron spectro- (CVI)in the apparatus used for the fabrication of real nd scopy (AES)depth profiles, recorded from fracture composites and under similar T-P conditions(typically at surfaces both on debonded fibers [see Fig. I(b) and on 00'C-1000C and under few kPa or few 10 kPa, depend- their trough in the matrix, and (i by parallel electron ing on the nature of the precursor). Hence, micro/mini energy loss spectroscopy(P-EELS)in a transmission elec tron microscope(TEM). Longitudinal thin foils of micro- ques closely related to those used for the corresponding real composites were prepared according to a technique which composites, with however two important differences: (i)the has been depicted elsewhere [11] processing time is much shorter and; (ii)the handling of the Micro-and mini-composites were tensile tested at room specimens requires specific care. Examples of micro/mini- temperature with tensile devices built in-house and composites are shown in Figs. I and 2 described elsewhere [25-27]. Microcomposites were tested The characterization of micro/mini composites requires specific experimental procedures owing to the small radial size of the specimens (a Nicalon/SiC microcomposite has an I Auger PHI 5590, from Physical Electronics PEELS 666-3K, from Gatan (USA). overall diameter of about 20 um for a fiber volume fraction, CM 30 ST, from Philips (NL)interphases with elementary layer thicknesses of a few nm can only be deposited (infiltrated) in a controlled manner by P-CVD/P-CVI [22,23]. In a last step, the SiC (or carbon) matrix was deposited (infiltrated) by conventional CVD (CVI) in the apparatus used for the fabrication of real nD composites and under similar T–P conditions (typically at 9008C–10008C and under few kPa or few 10 kPa, depend￾ing on the nature of the precursor). Hence, micro/mini composites are fabricated according to processing techni￾ques closely related to those used for the corresponding real composites, with however two important differences: (i) the processing time is much shorter and; (ii) the handling of the specimens requires specific care. Examples of micro/mini￾composites are shown in Figs. 1 and 2. The characterization of micro/mini composites requires specific experimental procedures owing to the small radial size of the specimens (a Nicalon/SiC microcomposite has an overall diameter of about 20 mm for a fiber volume fraction, Vf ˆ 0.50, corresponding to that commonly observed for the corresponding real nD-composites). The chemical analysis of the FM-interfacial zone was performed according to two complementary techniques: (i) by Auger electron spectro￾scopy (AES)1 depth profiles, recorded from fracture surfaces both on debonded fibers [see Fig. 1(b)] and on their trough in the matrix, and (ii) by parallel electron energy loss spectroscopy (P-EELS)2 in a transmission elec￾tron microscope (TEM)3 . Longitudinal thin foils of micro￾composites were prepared according to a technique which has been depicted elsewhere [11]. Micro- and mini-composites were tensile tested at room temperature with tensile devices built in-house and described elsewhere [25–27]. Microcomposites were tested R. Naslain et al. / Composites: Part A 30 (1999) 537–547 539 Fig. 3. Mechanical testing of micro/minicomposites: (a) tensile specimens; (b) tensile device for minicomposite tests; and (c) apparatus for lifetime measurements in air at high temperatures of SiC/SiC microcomposites, according to Ref. [9, 12, 26]. 1 Auger PHI 5590, from Physical Electronics. 2 PEELS 666-3 K, from Gatan (USA). 3 CM 30 ST, from Philips (NL)