中文摘要：

从宏、微观的角度研究了碳纤维增强聚酰亚胺树脂基MT300/KH420复合材料的高温力学性能,重点揭示了MT300/KH420复合材料[0°]14和[±45°/0°/90°/＋45°/0°2]s层合板在常温~500℃的弯曲性能变化规律。研究表明：MT300/KH420复合材料高温力学性能优异,[0°]14层合板在420℃的弯曲强度保持在51%以上,弯曲模量在500℃以内变化很小。[0°]14层合板在常温下断口粗糙,且贯穿厚度,表现为脆性破坏;随温度升高,树脂流动性增强,呈现出黏弹效应,破坏逐渐集中在加载点处,在500℃,部分树脂热解,纤维束脱离基体并氧化。[±45°/0°/90°/＋45°/0°2]s层合板高温弯曲性能较为稳定,主要破坏为上、下表面沿45°方向开裂,并伴有层间分离,在500℃出现严重分层破坏;相比于受基体控制的层合板弯曲性能,温度对受纤维控制的层合板弯曲性能影响较小。

英文摘要：

The high-temperature mechanical properties of carbon fiber reinforced polyimide resin matrix MT300/ KH420 composites were studied both in macro and micro scale, during which the flexural property variation rule for MT300/KH420 composites of laminates with ply orientation of [0°]14 and [±45°/0°/90°/＋45°/0°2]s Is were especially analyzed at temperature ranging from ambient temperature to 500℃. Research shows that MT300/KH420 composite has good mechanical property at high temperature. The flexural strength of [0°]14 laminates exhibit a 51% retention at 420℃, while at 500℃ it changes little. At ambient temperature, [0°]14 laminates exhibit brittle fractures with a rough facture surface and crack growth direction along thickness. As temperature rises, resin tends to have a stronger flowability, leading to a viscoelastic behavior, while failure mainly occurs at the loading nose. At 500 ℃, thermal exposure has caused the decomposition of resin matrix, leaving separations between the bundles of the oxidated fibers. As for [±45°/0°/90°/＋45°/0°2]s Is laminates, the flexural properties show a more stable retention at high temperature. Crack along 45° direction at outer surfaces as well as interlamination are the main failure modes. At 500 ℃, a severe delamination happens. Compared with matrix-dominated laminates, the flexural properties of fiber-dominated ones are less dependent on temperature.