碳纤维增强聚酰亚胺树脂基复合材料MT300/KH420高温力学性能(I)——拉伸和层间剪切性能

研究了碳纤维增强聚酰亚胺树脂基复合材料MT300/KH420的高温力学性能, 重点揭示了MT300/KH420的[0°]₇、[0°]₁₄ 和[±45°/0°/90°/+45°/0°₂]_s层合板在常温~500 ℃的拉伸和层间剪切性能的变化规律。结果表明:在350 ℃以内,[0°]₇层合板拉伸强度随温度升高有所提高, 拉伸模量几乎不变, 在420 ℃时拉伸强度和模量均出现明显下降, 在500 ℃时分别保持在65%和83%以上, 表现出优异的高温拉伸性能。MT300/KH420的[0°]₁₄层合板层间剪切强度在常温~420 ℃随温度升高不断降低至52.8%, 在高温下呈现出黏弹效应, 且在420 ℃时最为明显。相比于单向层合板, [±45°/0°/90°/+45°/0°₂]_s多向层合板高温力学性能较为稳定, 且由纤维控制的纵向试件力学性能受温度影响较小。 

High-temperature mechanical properties of carbon fiber reinforced polyimide resin matrix composites MT300/KH420(I)-Tensile and interlaminar shear properties

The high-temperature mechanical properties of carbon fiber reinforced polyimide resin matrix composites MT300/KH420 were studied,during which the tensile and interlaminar shear performance variation rule of MT300/KH420 laminates with[0°]7 ,[0°]14 and [± 45°/0°/90°/+45°/0°2 ]s fiber orientations were especially analyzed at temperature ranging from ambient temperature to 500 ℃.Results show that tensile strength of [0°]7 laminate shows an increase while tensile modulus changes little with the increase of temperature until 350 ℃.At 420 ℃ tensile strength and modulus reduce significantly,and at 500 ℃,65% and 83% of their pristine values remain,exhibiting an excellent high-temperature tensile property.As temperature rises,interlaminar shear strength of MT300/KH420 laminates with[0°]14 degrades continuously from ambient temperature to 420 ℃ where a retention rate of 52.8% is observed.A viscoelastic effect occurs at high temperature,especially at 420 ℃ it turns to be the most severest. Compared with unidirectional laminates,[± 45°/0°/90°/+45°/0°2 ]s multidirectional laminates show more stable high-temperature mechanical properties.Mechanical properties of fiber-dominated longitudinal specimen are less de-pendent on temperature.