摘要
采用榉木和水曲柳两种木材作为原材料,在800℃下炭化,然后用丙烷作为前驱体,使用等温化学气相沉积法在1050℃下沉积30h,制备出两种木基C/C复合材料。使用扫描电镜观察了两种木材炭化后和沉积后的微观形貌,利用三点弯曲法测定了两种木材炭化后和沉积后的力学性能,通过断口显微照片分析了它们的断裂机理。结果显示,有大量的热解炭沉积在孔隙内壁上,由榉木制备的木基C/C复合材料相比水曲柳获得了较快的沉积速率,密度达到0.713g/cm3,获得了更高的弯曲强度和弯曲模量,分别达到了17.6MPa和8.58GPa,这两种木基C/C复合材料都属于脆性断裂,榉木基C/C复合材料的断裂机理为晶间断裂,而水曲柳基C/C复合材料则表现晶间断裂和空洞聚集两种机理。
C/C composites were prepared from beech and ash as raw materials, which were firstly carbonized at 800℃ and then deposited at 1 050℃ for 30 h with propane as precursor by chemical vapor deposition. The microstructures of carbonized and de- posited wood samples were investigated by scanning electron microscope, the mechanical properties were measured by the three- point bending testing method and their fracture mechanism was analyzed by fractographs. Results showed that the pyrocarbons were found to grow inside the pores of two composites. A C/C composite with the density of 0. 713 g/cm3, flexural strength of 17.6 MPa and flexural modulus of 8.58 GPa was obtained from beech wood. These two kinds of C/C composites show brittle fracture. The fracture mechanism of beech sample is inter-granular fracture mechanism, while ash sample exhibits both the inter-granular fracture mechanism and void coalescence mechanism.
出处
《炭素技术》
CAS
CSCD
2008年第5期26-30,共5页
Carbon Techniques
关键词
木材
化学气相沉积
微观结构
力学性能
断裂机理
Wood
chemical vapor deposition
microstructure
mechanical properties
fracture mechanism
作者简介
蒋娜 女 1982年出生，辽宁人，硕士研究生，E-mail：jiangna@ss．buaa．edu．cn。
