钛-铝双丝超音速电弧喷涂过程中熔滴粒子几何特性研究

为了研究工艺参数对钛-铝双丝超音速电弧喷涂熔滴粒子尺寸的影响规律,通过对喷枪出口处气流速度、气体质量流率和金属熔滴质量流率的分析测定,以Nukiyama-Tanasawa模型为基础,建立了喷涂粒子的平均直径与喷涂电压和电流间的解析关系,并对喷涂电压和电流对熔滴粒子平均直径的影响进行了计算机模拟仿真.结果表明:在喷枪结构和雾化气体压力一定时,雾化粒子的平均直径随喷涂电流的增大而增大,随喷涂电压的升高而减小,但总的变化幅度却较小.利用激光粒度分析仪对一定喷涂工艺条件下所得的粒子平均直径进行实验分析,结果与计算值之间的相对误差为9.52%,扫描电镜观察表明粒子形态以球形颗粒为主.

Study on Geometry Character of Molten Droplet Atomizing during Titanium-aluminum Twin Wires Supersonic Arc Spraying

The influence of arc spraying parameters on the droplet size of titanium and aluminum was studied.The outlet velocity and mass flow ratio of gases and molten droplet mass flow ratio were determined firstly for supersonic wires arc spray(SWAS).On the basis of Nukiyama-Tanasawa's model about liquid droplet atomization average diameter,the analytic expressions of the molten droplet mean diameter between spray voltage and current in titanium and aluminum supersonic wires arc spray was derived,the correlation with arc spray parameters(voltage and current) droplet mean diameters were simulated by computer. The results show that the mean diameter of droplet increases with adding of spray current,and decreases with rising of spray voltage,but the extent of mean diameter changing is very finites at the certain gas pressure and spray nozzle structure.The particle size of spray droplet atomized determining by laser granularity analyzer,the relative error between calculation value and measure result is 9.52%.The shape of the majority of particles sprayed is sphericity by scanning electron microscopy observing.