1. XRD patterns of as-received fibers and fibers after heat-treatment between 600-1400 ℃

2. SEM images of as-received fiber (a) and fibers after heat-treatment at (b) 1200, (c)1300, (d) 1400 ℃

3. TEM images of SIC550 fiber after heat-treatment at 1300 ℃ for 1 h

4. Room temperature tensile strength (a) and strength retention rate (b) of SIC550 fiber after heat-treatment at different temperatures in contrast to that of ALF2220S fiber reported by Jiang et al.^[14]

5. High temperature tensile strength of as-received SIC550 multifilament and high temperature tensile strength of SIC550 multifilament after heat-treatment at 1300 ℃ for 15 min

6. XRD patterns of the fracture aeras of SIC550 fibers after tensile strength test at 1250 ℃ (a) and 1300 ℃ (b), and of SIC550 fibers after heat-treatment at 1300 ℃ for 15 min (c)

7. TEM images for the fracture areas of SIC550 fibers after tensile strength test at 1250 ℃ (a,c,e), and for SIC550 fiber after heat-treatment at 1200 ℃ for 1 h (b,d,f) Bright field images (a, b) with insets in (a or b) showing the correpongding SAD patterns; Dark field images (c, d), and high-resolution images (e, f)

8. High temperature tensile strength (a) and strength retention rate (b) for SIC550 filaments at different temperatures, in contrast to Nextel 720 filaments and CeraFib filaments reported by Almeida et al.^[4]

9. Room temperature tensile strength of SIC550 filaments at different gauge lengths