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选用特种工程塑料PEI,对其拉伸断裂的断口形貌进行了系统地宏观和微观观察,总结了PEI拉伸断面的典型形貌特征,并研究了各典型形貌随加载速率的变化规律。宏观断口分析表明:加载速率≦1 mm/min时,可将断面划分为平坦区、粗糙区和最后断裂区;拉伸速率>1 mm/min时,可将断面划分为平坦区、肋区和最后断裂区。微观断口分析和定量测试表明:平坦区可分为3种特征类型,且随加载速率升高,平坦区面积先呈迅速下降趋势,然后趋于平缓;粗糙区的典型形貌为礼花形貌,且随裂纹的扩展,粗糙区的粗糙度呈逐渐减小的趋势;肋状形貌由光滑带和粗糙带交替组成,且随加载速率增大,断面肋条宽度增大。
The special engineering plastic (PEI) was chosen to systematically macroscopically and microscopically observe the fracture morphology of the tensile fracture. The typical morphology of the PEI tensile section was summarized. The variation of each typical morphology with the loading rate was also studied. The macro-fracture analysis shows that the cross-section can be divided into flat area, rough area and final fracture area at the loading rate of 1 mm / min. When the tensile rate exceeds 1 mm / min, the cross-section can be divided into flat area, Last break zone. The microscopic fracture analysis and quantitative tests show that the flat areas can be divided into three types of features. With the increase of loading rate, the flat area decreases rapidly first and then tends to be gentle. The typical morphology of the rough area is fireworks, With the extension of crack, the roughness of the rough area tends to decrease gradually. The ribbed surface is composed of the smooth zone and the rough zone alternately. With the increase of the loading rate, the rib width of the section increases.