摘要
利用分离式霍普金森压杆(SHPB)装置对三维连通网状SiC陶瓷/Zr基非晶复合材料进行不同应变率下的动态压缩实验,并与准静态压缩实验结果比较.利用X射线衍射仪和扫描电子显微镜研究了复合材料的相组成和断口形貌.结果表明:在压缩条件下三维连通网状SiC陶瓷/Zr基非晶复合材料的断裂发生在弹性变形阶段,断裂前几乎观察不到塑性变形;复合材料的准静态压缩强度达到了1 270 MPa,高于在动态压缩中的断裂强度1 100 MPa.试样发生纵向劈裂和剪切断裂,准静态下试样形成的破片数量较多,动态加载条件下试样破碎成数量较少的较大块体.三维连通网状SiC陶瓷断口形貌为层片状、台阶式的解理断裂,非晶合金发生粘性流动,在变形过程中形成脉状花样,在高应变率加载条件下,非晶热软化严重,断口形貌复杂多样.
Uniaxial compressive response of 3D-net SiC/Zr-based amorphous composites was investigated at quasistatic and high strain rates in the range of 10^-3 and 10^3 s^-1, by means of WDW-E100D Testing Machine and Split Hopkinson pressure bar （SHPB）, respectively; the phase structure and failure surfaces were identified by X-ray diffraction and scanning electron microscopy （SEM）. It was found that the samples exhibit elastic deformation followed by catastrophic failure without obvious yielding under compressive loading. The dynamic compressive strength increases with the strain rates increasing, and is little lower than the quasi-static compressive strength 1 270 MPa. The failure mode of the composites is a mixture combining splitting and shear fracture, the quasistatically deformed specimens fractured into several fragments, the dynamically loaded specimens fractured into two or three larger fragments. The microscopic failure modes are typical cleavage fracture of 3D-net SiC and inhomogeneous flow deformation of the amorphous alloys matrix, the fracture surfaces of the amorphous phase become complex in high strain-rate loading.
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2006年第5期825-829,共5页
Journal of Harbin Institute of Technology
基金
国防科技基金资助项目(00J12.1.7.BQ0123)
