【摘 要】
：
Laser cladding technology is to deposit a clad layer covering on the surface of substrate,in order to achieve enhanced corrosion and wear properties by supplying powder or wire.The quality of the gas
【机 构】
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Department of Electronic Engineering,Kao Yuan University,Taiwan,R.O.C.
【出 处】
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13th International Conference on Liquid Atomization and Spra
论文部分内容阅读
Laser cladding technology is to deposit a clad layer covering on the surface of substrate,in order to achieve enhanced corrosion and wear properties by supplying powder or wire.The quality of the gas powder stream and interaction among gas jet,powder jet and laser beam determine the substrate cladding quality,powder utilizing efficiency and the shielding of the melt area in the powder-fed laser cladding.The objective of the present study is to analyze the gas powder stream and interactions among particles,gas flow and laser thermal source.The commercial CFD package is adopted to solve the turbulent thermal two-phase flow during powder feeding and heating processes of laser cladding.The powder focus and surrounding flow structure evolution are predicted under conditions closer to the experimental processing environment.Particle laser heating mainly depends on the laser power levels as well as the residence time in the heating zone.And the flow structure and particle velocities determine the particle location,distribution,and residence time.The selection of particle absorptivity is very crucial in numerical modelling.The generation of novel expression of temperaturedependent particle absorptivity is urgently needed for process prediction of laser cladding in the near future.Physically,the particle absorptivity could be treated as the synthesis of particle reflectivity,absorptivity,and laser attenuation.Future experimental works are needed to measure the powder laser energy absorption and provide the experimental results for facilitating numerical models to select proper particle absorptivity.
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