Abstract
3D C/SiC composites with different CVD SiC coating and a bulk CVD SiC material were prepared by low pressure chemical vapor infiltration/deposition and the effects of oxidation and heat treatment on the thermal expansion of the composites were investigated. The expansion behavior of the composites can be changed by their coating thickness. The thicker the coating, the more largely it can be changed. When the coating is thick enough, it cannot be changed. The oxidation at 700°C and the heat treatment at 1400°C can decrease the interfacial bonding strength of the composites, and then their thermal expansion behavior is similar to that of the bulk CVD SiC. The longitudinal CTE of the composites is decreased and then increased by the oxidation at 700°C with increasing the weight loss. The effect of heat treatment is not related to the coating thickness besides the temperature. The oxidation and the heat treatment at 1400°C has a similar effect on the expansion behavior of the composite with four-layer coating, but has a completely different effect on that of the composite with two-layer coating above 1000°C.
| Original language | English |
|---|---|
| Pages (from-to) | 377-382 |
| Number of pages | 6 |
| Journal | Science and Engineering of Composite Materials |
| Volume | 10 |
| Issue number | 5 |
| State | Published - 2002 |
Keywords
- Carbon fiber composites
- Heat treatment
- Oxidation
- Thermal expansion