February 2003 Influence of Interfacial Roughness on Fiber Sliding in Oxide Composites with La-Monacite 313 PUSHOUT monazite alumina matrit s um 200m soo nm 50 nm Fig. 10. Monazite coating on mullite fiber: region thought to have experienced tension during fiber sliding(as in Region A, Fig. 9). Monazite next to fiber is mostly undamaged, but entire coating is cracked. Compression increases toward right side of micrograph material with high density of dislocations requires lattice diffusion other ceramics, such as alumina and zircon, at similar homologous for dislocation climb, o whereas recrystallization after amorphiza temperatu measurements of nucleation tion by radiation damage does not require such diffusion. Never tallization, grai nd diffusion are needed to theless, the resistance of monazite to amorphization hints that whether recrys nsely deformed mona m solid-state processes in monazite are faster than those in many occur near roo 2um, PUSHOUT→mnmm1m monazite 100nm almina matrie 200nm Fig. 11. Monazite coating on mullite fiber: region thought to have experienced compression during fiber sliding(as in Region B, Fig. 9). Coating is heavily deformed through entire thickness, although with grain-to grain variation. Large cracks tend to run NW-SE.material with high density of dislocations requires lattice diffusion for dislocation climb,50 whereas recrystallization after amorphiza￾tion by radiation damage does not require such diffusion. Never￾theless, the resistance of monazite to amorphization hints that solid-state processes in monazite are faster than those in many other ceramics, such as alumina and zircon, at similar homologous temperatures.60 Independent measurements of nucleation, recrys￾tallization, grain growth, and diffusion are needed to determine whether recrystallization of intensely deformed monazite might occur near room temperature. Fig. 10. Monazite coating on mullite fiber: region thought to have experienced tension during fiber sliding (as in Region A, Fig. 9). Monazite next to fiber is mostly undamaged, but entire coating is cracked. Compression increases toward right side of micrograph. Fig. 11. Monazite coating on mullite fiber: region thought to have experienced compression during fiber sliding (as in Region B, Fig. 9). Coating is heavily deformed through entire thickness, although with grain-to-grain variation. Large cracks tend to run NW–SE. February 2003 Influence of Interfacial Roughness on Fiber Sliding in Oxide Composites with La-Monazite 313