J. Deng et al./Ceramics international 36(2010)299-306 0.5 ON5 stress-free nozzle ON5 stress-free nozzle E5 ■LN3 layered nozzle ■LN3 layered nozze 口LN2 layered nozzle □LN2 nozzle 口 LNI layered nozzle 二 口LN 0.2 Nozzles Fye d Come ia t he bed rt aiai of e L:. LN, LN Flg ns ofte o le o e o NN N N uy ed ovales relatively smooth in contrast to that of the N5 stress-free nozzle. 3.4. Discussion From Fig. 10d, the micro-structure can be seen clearly. In this structure,the"white"phase with clear contrast is(W,TiC, and When the erosive particles hit the target at low angles such as the grey phase is Al2O3. No sign of plowing was found both at the nozzle wall surface in CwS burning processes, most of the the wall surface of lnl nozzle CwS particles traveled almost parallel to the nozzle wall, and Fig 8. Exit hole profiles of the worn CWS nozzles after 120 h operation: (a) LNI layered nozzle, (b)LN2 layered nozzle, (c)LN3 layered nozzle, and(d) N5 stress-relatively smooth in contrast to that of the N5 stress-free nozzle. From Fig. 10d, the micro-structure can be seen clearly. In this structure, the ‘‘white’’ phase with clear contrast is (W,Ti)C, and the grey phase is Al2O3. No sign of plowing was found both at the wall surface of LN1 nozzle. 3.4. Discussion When the erosive particles hit the target at low angles such as the nozzle wall surface in CWS burning processes, most of the CWS particles traveled almost parallel to the nozzle wall, and Fig. 7. Comparison of the erosion rates of the LN1, LN2, LN3 layered nozzles and N5 stress-free nozzle. Fig. 6. Comparison of the hole diameter variation of the LN1, LN2, LN3 layered nozzles and N5 stress-free nozzle. Fig. 8. Exit hole profiles of the worn CWS nozzles after 120 h operation: (a) LN1 layered nozzle, (b) LN2 layered nozzle, (c) LN3 layered nozzle, and (d) N5 stress￾free nozzle. J. Deng et al. / Ceramics International 36 (2010) 299–306 303