加载速率对3D-C/SiC不同温度拉伸性能的影响

Influence of Loading Rates on 3D-C/SiC Tensile Properties at Different Temperature

研究了在室温、1100和1500℃夹头位移速率分别为0.008,0.06和5.82mm/min对CVI工艺制备的3D-C/SiC拉伸性能的影响。拉伸中用钨-铼热电偶测温,真空度为10-3Pa,LVDT测量变形。结果表明,室温条件下材料的断裂应力随夹头位移速率的增大而增加;1500℃断裂应力随夹头位移速率的增大而减小;1100℃条件下断裂应力基本不随变形速率而改变。随着夹头位移速率的提高,断裂应变减小,初始弹性模量增加。分析了可能造成以上现象的因素。

The tensile performance of 3DC/SiC preformed by CVI method was investigated in different temperatures and tensile crosshead displacement rates The tensile experiment was carried out in vacuum condition Testing temperature were room temperature, 1100℃,1500℃ and displacement rates are 0008,006,582 mm/min respectively Experimental results show that fracture stress increases as the crosshead displacement rate increased at room temperature, but it is in reverse at 1500℃ The fracture stress does not chang as the crosshead displacement rate varied at 1100℃ The fracture strain decreases and the initial modulus increases as the crosshead displacement rate increased 