三维连通网状SiC陶瓷/Zr基非晶复合材料动态变形特征

利用分离式霍普金森压杆装置,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,采用扫描电子显微镜研究复合材料的动态变形特征和断口形貌.结果表明:复合材料的动态压缩强度随着打击速度的增加而增加;试样发生劈裂和剪切断裂,陶瓷相断口形貌为层片状、台阶式的解理断裂,非晶合金发生粘性流动,断口形貌复杂多样.在应变率＞104 s-1的冲击载荷下,非晶相表现为软化后的多重脊状条带.复合材料断口上大量的非晶球形液滴及非晶软化条带的发现表明,绝热温升在非晶变形与断裂过程中起重要作用.

Dynamic Deformation and Fracture Behavior of 3D-Net SiC/Zr-Based Amorphous Matrix Composites

Dynamic deformation and fracture behavior of 3D-net SiC/Zr-based amorphous matrix composites at room temperature and various strain rates in compression was investigated by means of the split Hopkinson pressure bar(SHPB).The phase structure and failure surfaces were identified by scanning electron microscopy(SEM).It was found that,the dynamic compressive strength increases with increasing strain rates.The mode of failure of the composites is a mixture combining splitting and shear fracture.3D-net SiC exhibits typical cleavage fracture,and inhomogeneous flow deformation of the amorphous alloys matrix occurs leaving complex fracture surfaces.Under higher shock loading(rate of strain>104?s(-1)),substantive elongated ridge-like structure(melted belts) were observed on the fracture surface of Zr-based amorphous.The observed numerous liquid droplets and melted belts on the fracture surface demonstrated that the adiabatic heating exerts a significant effect on the fracture behavior of the amorphous alloys.