| The surface accuracy of the parts affects the appearance,performance,reliability and life span of the parts,Laser cladding 3D forming has a series of advantages such as short manufacturing process,good cladding quality and high material utilization rate.However,this method has been still in the blank manufacturing stage so far.According to the demand,the surface morphology,waviness and roughness need to be improved by subsequent finishing.Based on the laser feed powder technology,this paper studies the process method of the relatively high precision surface formed by single melting and cladding.The experiment and detection system of laser feed powder cladding were constructed.The energy distribution of hollow ring laser is studied,and the temperature field distribution of ring laser is simulated numerically based on ANSYS simulation software,and the temperature field distribution is verified by infrared thermometer.The influence of ring laser energy and temperature distribution on the surface precision of laser cladding was analyzed.The coupling law of inside feed powder is studied.Analysis of the powder of different feeding tube bundle of characteristics and collimating pressure influence on powder beam cluster degree,the feeding tube glass can achieve good powder cluster degree,fitting the relationship between the collimation pressure and powder spot diameter,to explore the light powder coupling mode provide a basis for the influence on the roughness.The effects of laser power,scanning speed and powder feeding rate on the surface quality of single channel were studied.It is found that the laser power has a significant effect on the surface quality of single channel cladding layer.It provides a basis for the selection of forming process parameters.In this paper,three kinds of coupling modes of light powder in the process of laser feed powder cladding are put forward,and different coupling modes of light powder are formed by adjusting the powder cluster degree and the ring spot defocusing amount,and the stacking test of thin-walled parts of straight wall is carried out under different coupling modes.The effect of the coupling mode of optical powder on the surface roughness of thin-walled straight wall was studied.The optical powder coupling mode of "light coated powder" is the key technology to improve the surface quality of formed parts,which provides the key technology for forming straight wall thin-walled parts and multi-component twisted thin-walled parts.The effects of laser power,scanning speed and powder feeding rate on the surface quality of thin-walled straight wall parts were studied,and the surface quality was characterized by two indexes:surface roughness and surface waviness.Forming multi-component twisted thin-wall parts with smooth and bright surface,no defects and oxidation layer,less sticky powder,surface roughness up to 1.75-2.83 ?m,surface ripple up to 16.04-30.15?m,forming parts with good surface quality.Compared with the traditional laser cladding,the surface roughness,surface viscosity and surface waviness are significantly improved.The grain size of the formed part was fine and showed dendrite structure,compact structure,no obvious pores,cracks and other defects,and achieved good metallurgical effect.Compared with the traditional laser cladding process,the parts with relatively high precision surface can be formed by using the laser internal feeding powder at one time,which is of positive significance for improving the laser cladding process level and meeting the requirements of direct application or less follow-up finishing in some projects. |
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