CAJ | 학술논문

以z向穿插炭棒、x-y向铺层纤维束法编织的软硬混编4D炭纤维预制体为增强体，采用沥青液相浸渍/炭化法制备了4D-C/C复合材料，研究了材料z向（炭棒方向）高温弯曲行为及损伤机理。结果表明：在室温~2100℃范围，随着温度的升高，4D-C/C复合材料z向弯曲强度呈现先增加后减小的趋势，在室温~1800℃时弯曲强度呈现增加的趋势，1800℃后随着温度升高弯曲强度开始逐渐降低，但当温度达到2100℃时其弯曲强度仍比室温下稍高。在室温~2100℃范围，随着温度的升高，软硬混编预制体增强沥青基4D-C/C复合材料z向弯曲断裂应变一直呈增加的趋势，而弯曲弹性模量总体呈减小的趋势。室温下4D-C/C应力-应变曲线几乎为线性关系，高温下4D-C/C复合材料z向弯曲破坏更加趋向于非线性的破坏模式。损伤表征结果表明，随着温度的升高，材料破坏时的最大损伤逐渐增加。
이z향천삽탄봉、x-y향포층섬유속법편직적연경혼편4D탄섬유예제체위증강체，채용력청액상침지/탄화법제비료4D-C/C복합재료，연구료재료z향（탄봉방향）고온만곡행위급손상궤리。결과표명：재실온~2100℃범위，수착온도적승고，4D-C/C복합재료z향만곡강도정현선증가후감소적추세，재실온~1800℃시만곡강도정현증가적추세，1800℃후수착온도승고만곡강도개시축점강저，단당온도체도2100℃시기만곡강도잉비실온하초고。재실온~2100℃범위，수착온도적승고，연경혼편예제체증강력청기4D-C/C복합재료z향만곡단렬응변일직정증가적추세，이만곡탄성모량총체정감소적추세。실온하4D-C/C응력-응변곡선궤호위선성관계，고온하4D-C/C복합재료z향만곡파배경가추향우비선성적파배모식。손상표정결과표명，수착온도적승고，재료파배시적최대손상축점증가。
4D preforms woven with carbon fiber bundles and carbon rods were densified by repeated pitch impregnation and high temperature carbonization to obtain 4D-C/C composites. The high temperature flexural behavior and damage mechanism of 4D-C/C composites were examined on z (carbon rod) direction from room temperature to 2 100℃. As a result, with the rising of temperature, flexural strength of 4D-C/C composite on z direction has a tendency of increasing first then decreasing between room temperature and 2 100℃. Flexural strength of 4D/C/C composite is prone to increasing before 1 800 ℃,decreasing gradually after 1 800 ℃.But when temperature goes to 2 100℃,the flexural strength is still higher than that of room temperature. With the rising of temperature, flexural strain to failure of 4D-C/C on z direction increases continuously between room temperature and 2 100 ℃. In room tempera-ture,the curve relation of stress-strain behavior of 4D-C/C is almost linear while nonlinear in the high temperature,the character of the fraction pattern presents brittle failure while plastic failure in the high temperature.