同轴载气送粉激光熔覆粉末流参数研究

同轴气动送粉激光熔覆过程中,金属粉末落入熔池的速度、浓度的分布等物理参数对熔覆层的形貌有一定的影响。DPIV(d igital partic le im age veloc im etry)是试验确定粉末流运动规律的有效方法,通过建立DPIV试验装置,对同轴载气送粉装置输送的粉末的速度、浓度进行了取值计算。结果表明,随气体流量的增加粉末的浓度有一定的减少。沿z轴方向,存在发散汇聚在发散的变化,粉末粒子流量与粒子速度在一定范围内有线性关系,超出Mp=0.33g/s~0.83g/s,Vp=0~1.3m/s范围,其影响将减弱。

Research on the Coaxial Carrier-gas Powder Feed Laser Cladding

The various parameters metal particles transportation on the coaxial carrier-gas powder feeding affected the surfacing layer,s complex geometry and qualities greatly under the laser cladding process.In this paper,the velocity distribution of the powder particles in the coaxial,and the distribution of powder concentration at longitudinal axis from the nozzle exit were measured with the varied powder feed rate parameters by the application of digital particle velocimetry(DPIV).Experiments show that the velocity metal-powder particle is linear correlation with the gas and the powder mass flow rate.Outside the given the powder mass flow rate Mp=0.33g/s ~0.83g/s and particles transportation velocity Vp=0~1.3m/s,the effect of lessened is obvious.