KK Chawla et al. / Journal of the European Ceramic Society 20(2000)551-559 pronounced effect on the interfacial sliding stress. radial clamping stress by an amount proportional to A /r, Mackin et al. 5 observed sinusoidal modulations in the where A is the amplitude of the roughness and r the load-displacement curves of Saphikon/glass and Saphi- fiber radius. The roughness amplitude of Saphikon kon/y-TiAl composites identical in wavelength to the fibers, A, measured by atomic force microscopy(AFM) surface roughness of the Saphikon fibers Parthasarathy is 0.0077 um . The fiber radius r used in the present work et al. 8 found that sliding resistance increased with the is around 70 um, therefore the interfacial roughnes 1200 800 400 200十 80 100 220 Distance from the fiber axis um Fig. 10. Thermal stresses in a Saphikon/ five-dip monazite/alumina composite, where Vr=0.0l and AT=1000 C. The coating thickness is 0.5 pr 1200 1000 800 600 00 80 Distance from the fiber axis, um Fig. Il. Thermal stresses in a Saphikon/10-dip monazite/alumina composite where Vr=0.0l and AT=1000.C. The coating thickness is 0.5 um.pronounced e€ect on the interfacial sliding stress. Mackin et al.15 observed sinusoidal modulations in the load±displacement curves of Saphikon/glass and Saphi￾kon/g-TiAl composites identical in wavelength to the surface roughness of the Saphikon ®bers. Parthasarathy et al.18 found that sliding resistance increased with the radial clamping stress by an amount proportional to A/r, where A is the amplitude of the roughness and r the ®ber radius. The roughness amplitude of Saphikon ®bers, A, measured by atomic force microscopy (AFM) is 0.0077 mm.4 The ®ber radius r used in the present work is around 70 mm, therefore the interfacial roughness Fig. 10. Thermal stresses in a Saphikon/®ve-dip monazite/alumina composite, where Vf=0.01 and
T=1000C. The coating thickness is 0.5 mm. Fig. 11. Thermal stresses in a Saphikon/10-dip monazite/alumina composite where Vf=0.01 and
T =1000C. The coating thickness is 0.5 mm. K.K. Chawla et al. / Journal of the European Ceramic Society 20 (2000) 551±559 557