D.-S. Lim et al./Wear251(2001)l452-1458 orientation of the whiskers, as shown in Fig. 6 For sample Less micro-fracture but greater formation of rolls and debris T10, the lowest wear was obtained in the direction normal compaction are shown on worn surfaces of T20 samples as with lamination direction and highest in the direction paral- compared with sample A(Fig. 7(c)and()). The rolls are lel with the tape casting direction For sample T20, wear in the most frequently observed on the wear tracks of the T20 the direction parallel to whisker orientation is higher than sample at 673 K, as shown in Fig. 8. A higher magnifica- that in the direction normal for the whisker orientation tion of the micrograph of the rolls shows smaller diameters Similar orientation effect on the wear rate is observed for and distinguishes from whiskers( Fig. 9). The SEM micro- both low and high temperatures graphs of the worn surfaces of parallel, normal with the tape The worn surfaces of sample A and sample T20 at three casting direction, and normal with the lamination direction different temperatures are shown in Fig. 7. Smoother sur- at 873 K, are shown in Fig. 10. The smoothest feature is faces are shown for both A and T20 samples tested at 403K, shown on the worn surface of the normal to the lamination as shown in Fig. 7(a) and(b), respectively. For sample A, direction. EDS analysis confirmed that the worn surface had micro-fractured regions and smeared wear debris partie a much higher silicon content compared to that of unworn temperature(Fig. 7(a), (c)and( surface as shown in Fig. 11 (b) 5 um Fig. 7. SEM micrographs of wom surfaces for (a) sample A at 403 K,(b) sample T20 at 403 K,(c) sample A at 673K,(d) sample T20 at 673 K,(e) ple A at 873K and (f) sample 120 at 873KD.-S. Lim et al. / Wear 251 (2001) 1452–1458 1455 orientation of the whiskers, as shown in Fig. 6. For sample T10, the lowest wear was obtained in the direction normal with lamination direction and highest in the direction paral￾lel with the tape casting direction. For sample T20, wear in the direction parallel to whisker orientation is higher than that in the direction normal for the whisker orientation. Similar orientation effect on the wear rate is observed for both low and high temperatures. The worn surfaces of sample A and sample T20 at three different temperatures are shown in Fig. 7. Smoother sur￾faces are shown for both A and T20 samples tested at 403 K, as shown in Fig. 7(a) and (b), respectively. For sample A, micro-fractured regions and smeared wear debris particles increased with increasing temperature (Fig. 7(a), (c) and (e)). Fig. 7. SEM micrographs of worn surfaces for (a) sample A at 403 K, (b) sample T20 at 403 K, (c) sample A at 673 K, (d) sample T20 at 673 K, (e) sample A at 873 K and (f) sample T20 at 873 K. Less micro-fracture but greater formation of rolls and debris compaction are shown on worn surfaces of T20 samples as compared with sample A (Fig. 7(c) and (f)). The rolls are the most frequently observed on the wear tracks of the T20 sample at 673 K, as shown in Fig. 8. A higher magnifica￾tion of the micrograph of the rolls shows smaller diameters and distinguishes from whiskers (Fig. 9). The SEM micro￾graphs of the worn surfaces of parallel, normal with the tape casting direction, and normal with the lamination direction at 873 K, are shown in Fig. 10. The smoothest feature is shown on the worn surface of the normal to the lamination direction. EDS analysis confirmed that the worn surface had a much higher silicon content compared to that of unworn surface as shown in Fig. 11