EXPERIMENTAL METHOD TO STUDY EFFECT OF NANOMETRIC PARTICLE OXYDE PROTECTION GUN BARREL AGAINST EROSION

摘要

An increasing demand for improved gun system performance has led to the use of more energetic but more erosive gun propellant formulations. While improving performance, these new propellants can dramatically accelerate gun tube erosion, requiring more frequent tube replacement, and consequently increasing life-cycle costs. The erosion processes are complex and high temperature as well as high kinetic interactions will create severe thermal effects, high pressures and complex mechanical phenomena. One way to reduce this erosion is to use a wear protection, generally made with a mixture of wax and solid particles oxyde, used as solid form inside the ammunition. This paper presents an experimental method linked to a simple numerical algorithm to study the effect of nanometric particle oxyde on gun barrel protective action. This method makes it possible to assess the thermal protection effect and to select the best oxydes and concepts using low cost laboratory tests, before real scale tests. In this paper, we compare the effect of the addition of two types of inert powders on the combustion of a double base gun propellant. The two powders had the same chemical formula but the average size of particles are very different. In the first experiment, the both nanoparticles seems to modify the temperature. The microparticles didn't present such a behaviour and the chemical equilibrium properties ave very close to the calculated values.