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本文通过超声波将短碳纤维(Csf)与偏高岭土、α-Al2O3颗粒(α-Al2O3p)预分散混合,然后加入到碱金属溶液中的方式制备了及Csf单独以及Csf与α-Al2O3p复合强韧的无机聚合物基复合材料,研究了及Csf、α-Al2O3p含量对复合材料的组织结构,机械性能以及断裂行为的影响规律。结果表明:及Csf在基体中分散均匀。采用及Csf单独强韧复合材料的抗弯强度、断裂韧性随着纤维含量的增加都呈先减小后增加的规律,其中纤维含量为2 vol%时分别达到28.4 MPa和0.6 MPa.m1/2,相比基体分别增加了0.85倍和1倍。采用及Csf与α-Al2O3p复合强韧的无机聚合物基复合材料,虽然其抗弯强度较及Csf单独强韧的复合材料低并与α-Al2O3p的含量成反比,但是其断裂韧性较及Csf单独强韧复合材料的高,并在α-Al2O3p加入量为8 wt%时达到最大值为0.75 MPa.m1/2。复合材料在断裂过程中呈现非脆性断裂方式,并且及Csf与α-Al2O3p复合强韧的无机聚合物基复合材料在断裂过程中载荷位移曲线呈现锯齿形增长。复合材料断裂行为和断口分析表明,碳纤维的桥联,拔出是复合材料主要的强韧化机制。
In this paper, Csf alone and Csf and α-Al2O3p composite toughening were prepared by pre-dispersion mixing of short carbon fiber (Csf) with metakaolin and α-Al2O3p particles and then adding into alkali solution Inorganic polymer matrix composites, the effects of Csf, α-Al2O3p content on the microstructure, mechanical properties and fracture behavior of the composites were studied. The results show that: Csf dispersed evenly in the matrix. The flexural strength and the fracture toughness of the composites reinforced with Csf and the composite reinforced with Csf decreased first and then increased with the increase of the fiber content, respectively, with the volume content of 2 vol% reaching 28.4 MPa and 0.6 MPa.m1 / 2 respectively , Respectively, compared with the substrate increased by 0.85 times and 1 times. The fracture toughness of the composites reinforced with Csf and α-Al2O3p tougher than that of Csf alone is inversely proportional to the content of α-Al2O3p, although the flexural strength is lower than that of Csf. The strength of the composite alone is high and reaches a maximum of 0.75 MPa.m1 / 2 with an α-Al2O3p addition of 8 wt%. The composites showed non-brittle fracture mode during the fracture process, and the load displacement curves of the composites strengthened with Csf and α-Al2O3p tended to increase in a zigzag manner during the fracture process. Fracture behavior and fracture analysis of composite materials show that the bridging and pulling out of carbon fibers are the main strengthening and toughening mechanisms of composites.