CAJ | 학술논문

激光同轴送粉喷嘴是激光直接制造系统中核心部件之一,喷嘴的保护气体流场对金属粉末的流动和零件材料的性能影响较大.研究应用粒子图像测速(PIV)技术测量激光同轴送粉喷嘴轴截面保护气体的流场,并对此进行了相应的计算与分析.结果表明,喷嘴三个喷口之间的壁厚对喷嘴附近的流场影响较大,促使喷嘴喷口处产生两对对称旋涡,不利于粉末的输送和聚焦.喷嘴的三个喷口的喷出气流速度一致时,速度界面的湍流扩散和动量交换较小,将产生一个有利于输送金属粉末的稳定流场.
격광동축송분분취시격광직접제조계통중핵심부건지일,분취적보호기체류장대금속분말적류동화령건재료적성능영향교대.연구응용입자도상측속(PIV)기술측량격광동축송분분취축절면보호기체적류장,병대차진행료상응적계산여분석.결과표명,분취삼개분구지간적벽후대분취부근적류장영향교대,촉사분취분구처산생량대대칭선와,불리우분말적수송화취초.분취적삼개분구적분출기류속도일치시,속도계면적단류확산화동량교환교소,장산생일개유리우수송금속분말적은정류장.
Laser coaxial feeding powder nozzle is one of the core parts of laser direct manufacture system, which affects the metal powder flowing and part property greatly. This paper researches on the gas flow field of laser coaxial feeding powder nozzle by the use of PIV technology and numerical simulation. The results show that the wall thickness between the three nozzle exits of coaxial feeding powder nozzle influences the flow field greatly and brings up two pairs of symmetric vortex, which interferes powder feeding and converging. When the gas velocity of three nozzles is consistent, turbulent diffusion and momentum exchange on velocity interface is small,so a stable flow field is obtained for feeding metal powder.