高取向度石墨基复合材料力学性能及微观结构研究  

Mechanical Properties and Microstructure of Highly Oriented Graphite Matrix Composites

作　　者：魏春城[1] 叶长收 刘晓燕[1] 

机构地区：[1]山东理工大学材料科学与工程学院,淄博255049

出　　处：《人工晶体学报》2015年第8期2298-2302,共5页Journal of Synthetic Crystals

基　　金：山东省自然科学基金(ZR2014JL032;ZR2012EMM016)

摘　　要：以Zr B2和Si C为烧结助剂,采用流延-叠层-热压工艺制备高取向石墨基复合材料,并对其抗弯强度、断裂韧性、断裂行为以及微观结构进行了研究。结果表明:该石墨基复合材料结构完整,其中片状石墨颗粒平行热压面高度定向排列。弯曲强度和断裂性能及致密度都得到大幅度提高,垂直片层和平行片层方向测试的抗弯强度和断裂韧性分别为104 MPa、2.07 MPa·m1/2和84 MPa、1.97 MPa·m1/2。高取向石墨基复合材料受到不同方向力冲击时的断裂行为显著不同,垂直层面加压时断裂由脆性破坏变为非脆性破坏行为,断裂功达到145 J/m2为平行层面测试的2倍。非脆性破坏行为主要归因于层界和高度定向的片状石墨颗粒诱导裂纹偏转分叉以及片状石墨颗粒桥联拔出。Using ZrB2 and SiC as sintering aids,highly oriented graphite matrix composites were prepared by tap casting-stacking-hot press. The microstructures and mechanical properties of the composites at room temperature were investigated. The results indicate that the graphite matrix composites are structurally-complete and flake graphite particles formed a vertical arrangement under the parallel hot pressing surface height. The bending strength and fracture toughness of highly oriented graphite matrix composites are 104 MPa,2. 07 MPa · m1 /2（ ⊥ layer） and 84 MPa,1. 97 MPa · m1 /2（ ∥ layer）,respectively. which are higher than graphite ceramic. The fracture behavior of graphite matrix composites are significantly different under different testing directions. The fracture behavior of graphite matrix composites become non-brittle fracture no longer brittle rupture when testing directions paralleled to the layer. The fracture behavior changes due to bridging and pulling-out effect of the flake C and layer and microcracking and crack deflection from flake C and boundary of layer.

关 键 词：高取向度 石墨 流延 抗弯强度 断裂韧性 断裂行为 

分 类 号：TQ134.12[化学工程—无机化工]