【摘要】 为了制备适合激光熔覆的球形合金粉末,针对传统雾化喷嘴效率不高、粉末球形度不高且易堵嘴的情况,设计出一种气流出口处为laval型,带有辅助风孔和导液管的气雾化喷嘴。对喷嘴出口处进行气流仿真并用毕托管总压法进行测速,用U型水压力计在喷嘴中心线上进行气压分布测量,进行雾化实验,最后用扫描电镜(SEM)和霍尔流量计对粉末进行分析。结果表明,与传统喷嘴相比,设计喷嘴能在出口处产生超音速气流,且雾化过程中不易堵嘴,雾化效率明显提高。而且制取的粉末有较好的粒度分布,绝大部分呈球形,有良好的流动性,符合激光熔覆的要求。更多还原

【Abstract】 As to the low efficiency and low degree of sphericility with frequently impeded in atomizing process of traditional gas-atomizing nozzle,a new nozzle with laval outlet accompanied by ventilation hole and guiding pipe is designed to prepare spherical alloy powders for laser cladding.The gas velocity at the outlet of nozzle is simulated and measured by pitot tube total pressure method,and the air pressure on the nozzle centerline is tested by U-shaped water pressure gauge.After the atomization experiments,the powder achieved is analyzed by scanning electron microscoope(SEM) and Hall flowmeter.The results show that compared with the traditional nozzle,the innovative nozzle can produce supersonic flow at the outlet,the process of atomization is unimpeded,and the efficiency of atomization is improved significantly.With excellent characteristics of good liquidity and granularity distribution,the spherical powder can meet the requirement of laser cladding.更多还原