摘要
激光金属沉积成形过程中,送粉喷嘴结构参数一定时,载气式同轴送粉喷嘴的粉末流场主要受送粉参数影响如载气速度、送粉量。为了进一步改善现有送粉喷嘴的汇聚性和提高粉末利用率,基于固气两相流数值计算模型,应用FLUENT软件模拟两种因素对同轴送粉喷嘴粉末流场的影响。结果表明:载气流速过小则会导致粉末流汇聚焦点浓度较低;载气速度过大则焦点形状不规则,降低成形表面质量;载气流速过小或者过大都会导致粉末利用率降低。送粉量主要影响粉末流焦点中心的汇聚浓度和粉末流速度以及速度波动。数值计算结果对同轴送粉喷嘴设计和优化激光加工工艺参数具有一定的参考价值。
During the Laser Metal Deposition,when the coaxial feeding nozzle with carrier gas is fixed,its powder flow field is also influenced by gas-carrier flow rate and powder mass flow rate.To obtain better gathering characteristics and high utilization of powder, the FLUENT software is used to simulate powder flow field based on the gas-solid two-phase flow theory.The numerical simulation results indicate that the lower gas-cartier flow rate leads to lower concentration in powder now focal point;and the higher gas-carrier flow rate makes the focal point change to irregular shape and reduces the surface quality of the deposited parts.To get high utilization of power,the gas-carrier flow rate should be set carefully.Powder mass flow rate mainly influences gathering concentration of the focal point and powder flow speed and its fluctuation.The conclusion will benefit for coaxial nozzle designing and optimizing Laser processing parameters.
出处
《应用激光》
CSCD
北大核心
2012年第6期510-515,共6页
Applied Laser
基金
中航工业产学研专项资助项目(项目编号:CXY2011SH16)
关键词
激光金属沉积
同轴送粉
气固两相流
数值模拟
laser metal deposition： coaxial powder feeding： gas-solid two-phase flow： numerical simulation
