镀层材料热及力学特性对枪管寿命的影响

为研究枪管镀层材料性能对枪管寿命的影响，综合运用身管镀层剪切失效理论和疲劳损伤累积理论，提出了基于镀层界面剪切疲劳损伤的枪管寿命预测模型.以某小口径步枪为研究对象，基于有限差分法，对内膛涂镀铬、钽和氮化硅三种不同材料的枪管在10连发射击过程中的温度场分布、镀层内应力分布以及枪管寿命进行了数值计算，研究了镀层材料的热及力学特性对枪管寿命的影响.研究结果表明，镀层的热扩散系数、影响因子η及断裂长厚比是影响枪管寿命的几个关键性能，其中断裂长厚比对界面切应力和枪管寿命的影响最大，拥有较大断裂长厚比的镀层可以在射击过程中显著降低界面切应力，进而提高枪管寿命. 

Influence of Thermal and Mechanical Properties of Coating on Gun Barrel Life

To analyze the influence of coating material properties on gun barrel life, applying synthetically the theories of coating shear failure mechanism and fatigue cumulative damage, a life prediction model was proposed based on the theories of coating shearing failure and fatigue cumulative damage. Taking the small caliber gun barrels coated with Cr, Ta and Si₃N₄ ceramic respectively as study objects and 10-round burst shot firing as the process period, their near-wall temperature field, stress field and barrel life were numerically analyzed based on finite difference method, and the influence of coating properties on barrel life was analyzed. The results show that, the thermal diffusivity, the influence factor η and the cracked L/h ratio of coating are the key properties for barrel life. And the cracked L/h ratio of coating can bring a significant influence on interface shear stress and barrel life, and the coating with larger cracked L/h ratio can reduce the interface shear stress effectively during firing and then improve the barrel life.