发射药冲击断裂时的形态结构及其断裂破坏机理

MORPHOLOGICAL STRUCTURES AND FRACTURE MECHANISMS OF GUN PROPELLANTS DURING IMPACT FRACTURE

研究了以Lzod冲击方式获得的几种发射药断裂破坏时断裂面的形态结构。研究表明,低温下单基发射药表现为NC纤维束内纤维的断裂破坏,硝胺发射药为由NC粘接剂基体中尺寸大的RDX晶块的破裂导致应力更加集中而断裂破坏,硝基胍发射药是相界面缝隙导致破坏;高温下单基发射药的断裂方式是NC纤维内产生银纹到裂纹,并有部分微纤维的滑移而断裂破坏,而硝胺和硝基胍发射药主要是因相界面的脱湿和相界面间缝隙等形成裂纹后断裂破坏。本文还就如何改善硝胺和硝基胍发射药的冲击断裂性能提出了一些建议。

Gun propellants in the process of use are subjected to impact forces. In this article, the morphological structures of Izod impact fractured surfaces of several gun propellants are studied. The results showed that the homogeneous single base and non-homogeneous nitramine or nitroguanidine triple base gun propellants have different morphological structures and modes of fracture by the action of impact load and under conditions of different temperatures. At lower temperatures, fracture is caused by cracking of the fibers within the NC fiber bundle for the single base gun propellant, and by the more serious stress concentration as a result of large RDX crystal grains breaking in the NC binder for the nitramine gun propellant, and by the crack of adhesion interface between the NC binder matrix and the NQ crystals for nitroguanidine gun propellants. At higher temperatures, fracture is caused by the formation of original craze to final cracks within the NC fiber and by the microfiber slipping for the single base gun propellant, and by improper wetting and presence of gaps between the adhesion interfaces for the nitramine or nitroguanidine gun propellants. In addition, some suggestions are provided specifically as to ways of improving the impact fracture behaviour of nitramine and nitroguanidine gun propellants.