原位拉伸扫描电镜法研究GAP推进剂的损伤行为

Damage Behavior of GAP Solid Propellant by In-situ Tensile SEM Method

采用原位拉伸扫描电镜研究了GAP推进剂的损伤演化过程,并结合数字图像技术和分形维数的方法对裂纹演化进行了定量分析。结果表明,GAP推进剂在拉伸过程中的破坏首先发生在大粒径的AP颗粒集中分布区域,紧邻AP颗粒间少量的黏合剂基体断裂及脱粘;然后再到分散分布区域的AP颗粒及其附近位置处与黏合剂基体的脱粘;拉伸前期裂纹增加较为迅速,其后缓慢增加直到推进剂整体断裂;拉伸速率越慢,拉伸前期裂纹增加越快,且整个拉伸过程损伤程度越大;其中,拉伸速率为0.05 mm/min的拉伸过程损伤程度最为显著。

In-situ tensile scanning electron microscopy(SEM)observations were utilized to investigate the tensile fracture behavior of the GAP solid propellant.Quantitative analysis of fracture evolution is carried out by combining digital image technology and fractal dimension method.The results show that the microstructure damage first occurs in the concentrated distribution area of AP particles with large particle size,the fracture and debonding of small amount of adhesive matrix between adjacent AP particles starts.Then AP particles in the dispersed area and their adjacent positions are debonded to the adhesive matrix.The fracture increases rapidly in the early tension stage,and then the cracks become slowly till the whole propellant broke.The lower the tensile rate is,the faster the cracks grow,and the greater the damage degree in the tension process is.Among all the test tensile rates,the tensile rate of 0.05 mm/min was the most obvious one.