ZrW_(2)O_(8)-Cf/E51低/负热膨胀复合材料制备及超声时间对其热膨胀和力学性能的影响

Preparation of ZrW_(2)O_(8)-Cf/E51 low/negative CTE composites and effect of ultrasonic time on its thermal and mechanical property

为了制备低膨胀、高强、轻质复合材料,采用模压法制备了ZrW_(2)O_(8)-Cf/E51复合材料,并研究了超声时间对其微观组织、热膨胀行为和极限抗拉强度的影响。结果表明:在制备过程中颗粒团聚后容易受到纤维单丝阻挡并在纤维束表面聚集。在20 min之内,延长超声时间会减少ZrW_(2)O_(8)颗粒团聚。随着颗粒团聚的减少,复合材料断口会由平面状、无纤维拔出变为台阶状、有纤维拔出。在碳纤维和ZrW_(2)O_(8)颗粒的综合作用下,ZrW_(2)O_(8)-Cf/E51复合材料在热膨胀过程中膨胀量dL/L0会出现增大、减小和缓慢上升三个阶段,平均热膨胀系数也会出现相应的三个阶段。超声时间从5 min延长到20 min,ZrW_(2)O_(8)-Cf/E51复合材料的平均热膨胀系数降低了约130%,极限抗拉强度提高了约8%。

In order to prepare low expansion,high strength and light weight composites,ZrW_(2)O_(8)-Cf/E51 composites were prepared by compression molding method,and the effects of ultrasonic time on its microstructure,thermal expansion behavior and ultimate tensile strength were studied.The results show that the agglomerated particles will be blocked by the fibers and gather on the surface of fiber bundles during the preparation.Within 20 minutes,the agglomeration of ZrW_(2)O_(8)particles can be reduced by prolonging the ultrasonic time.With the decrease of particle agglomeration,the fracture surface of the composites will be changed from plane without fiber pull-out to uneven with fiber pull-out.During the thermal expansion process,the dL/L0of ZrW_(2)O_(8)-Cf/E51 composites show three stages:increase,decrease and slow increase under the combined action of carbon fiber and ZrW_(2)O_(8)particles.When ultrasonic time increases from 5 min to 20 min,the average thermal expansion coefficient of ZrW_(2)O_(8)-Cf/E51 composites decreases by about 130%,and the ultimate tensile strength increases by about 8%.