双层鞘气聚焦对气溶胶喷印粉末汇聚特性的影响

Effect of Dual-Sheath Gas Focusing on the Convergence Characteristics of Aerosol Jet Printing Powder

粉末气溶胶喷印(P-AJP)技术是通过载气携带金属纳米颗粒形成气溶胶,其依靠气体动能将金属纳米颗粒均匀、稳定地喷印沉积至基底上,形成导电线路。采用气固两相流理论,建立喷印头内外流场模型,并应用FLUENT软件中的离散相模型分析计算不同喷印头鞘气层锥角和鞘气体积流量对粉末流场汇聚特性的影响。仿真结果表明,在送粉量一定的情况下,第一层鞘气层倾角为70°,第二鞘气层倾角为40°时粉末汇聚特性较好,粉末利用率较高。并以此角度模型为基础,通过模拟仿真和实验验证得出了第一层鞘气体积流量和第二层鞘气体积流量对粉末聚焦特性的变化趋势基本一致,喷印导线线宽及气溶胶颗粒轨迹线线宽都随着鞘气体积流量的增加而减小,其证明了模型的合理性和可靠性,为后续粉末气溶胶喷印中喷印头的结构设计和优化提供了参考。

The powder aerosol jet printing(P-AJP)is a technology by carrying metal nano-particles in carrier gas to form an aerosol,which relies on the kinetic energy of the gas to uniformly and stably jet print and deposit the metal nanoparticles on the substrate to form a conductive circuit.Based on the gas-solid two-phase flow theory,the internal and external flow field models of the jet printing head were established,and the discrete phase model in the FLUENT software was used to analyze and calculate the influences of the cone angle of the sheath gas layer and the sheath gas volume flow rate of different jet printing heads on the convergence characteristics of the powder flow field.The simulation results show that when the powder feeding quantity is constant,the inclination angle of the first sheath gas layer is 70°,and the inclination angle of the second sheath gas layer is 40°,the powder convergence characteristics are better and the powder utilization rate is higher.Based on this angle model,through simulation and experimental verification,it is concluded that the change trends of the first layer sheath gas volume flow rate and the second layer sheath gas volume flow rate on the powder focusing characteristics are basically the same,and the line widths of jet printed wire and aerosol particle track line both decrease with the increase of sheath gas volume flow rate,which proves the rationality and reliability of the model,and provides reference for the structural design and optimization of the jet printing head in the subsequent powder aerosol jet printing.