冷喷涂过程中能量变化及沉积行为的模拟研究

来源期刊：金属学报2010年第4期

论文作者：巫湘坤 周香林 王建国 张济山

文章页码：385 - 389

关键词：冷喷涂； 能量分配系数； 数值模拟

Key words：cold spraying； partition coefficient of energy； numerical simulation

摘    要：采用有限元分析软件ANSYS/LS-DYNA,模拟了超音速冷喷涂过程中的颗粒碰撞过程,研究了高速颗粒与基板碰撞时的能量转化、分配以及颗粒沉积过程,分析了碰撞速度和材料特性对它们的影响.结果表明,碰撞过程中,颗粒和基板材料均发生塑性变形,使颗粒的动能被消耗,且绝大部分动能转变为材料内能.碰撞完成之后,颗粒动能被分配到颗粒和基板材料中,定义碰撞之后分配到颗粒中的与分配到基板中的能量之间的比值为能量分配系数K,K值过高或过低,均表明颗粒和基板之间变形能力相差较大,不利于颗粒与基板结合形成良好的涂层.系统初始动能以及颗粒与基板材料性能对K值都有影响.

Abstract: In this paper,the physical process during the impact of a cold spraying spherical particle with an infinite homogencous substrate was simulated using the finite element method(FEM). The effects of the impact velocity,the particle and substrate materials on the impact bebavior were investigated.The results show that a significant amount of the initial total kinetic energy of the particle is dissipated due to the plastic deformation of particle and substrate,finally transforming to their internal energies.An energy partition coefficient K,defined as the ratio of the energies distributed in the particle and substrate,has been introduced,which is closely related to the initial total kinetic energy of the particle and the deformability of the particle and substrate during the impact.It is found that it is difficult to make a particle with hight K and a substrate with low K cohere strongly.