Research On Process Basis And Mechanical Properties Of Laser Engineered Net Shaping Basis On Inclined Substrate

Additive manufacturing technology has high material utilization efficiency and the ability to form complex structural parts,as a result of which it has become a research hotspot in the manufacturing field recently.Laser cladding forming is an additive manufacturing technology with great flexibility and adaptability.However,it is difficult to meet the requirements for the manufacture of some structurally diverse parts in terms of forming efficiency and precision.Therefore,the hybrid machining which combining subtractive and additive manufacturing has drawn a lot of attention from researchers.The bonding between the additive and the substrate is important to the hybrid machining,especially on inclined surfaces that do not allow the parts to be flipped over.Therefore,the laser cladding forming on the inclined base surface had been researched in the paper.It mainly solved the problem of forming accuracy and quality on the inclined substrate,and analyzed the mechanical properties of the hybrid machining parts.1.In this paper,by analyzing the process of metal material melting by laser,the temperature distribution model of molten pool and the outer contour model of cladding layer were established,on top of which the analytic model of the contour displacement of laser cladding layer on the inclined substrate was established.The impact and regularity of process parameters(i.e.,laser power,scanning speed and powder feeding speed)on the profile displacement of cladding layer were analyzed.The displacement of cladding layer contour can be reduced by increasing the scanning speed and decreasing the powder-feeding speed.2.A single layer laser cladding forming process was studied.The influence of process parameters on the height,width,displacement and depth of the cladding layer was analyzed.The reasonable process parameters of laser cladding on different inclined substrate was determined,and the calculation correctness of the profile displacement model of cladding layer was also verified.3.Based on the single layer cladding process parameters,an experimental study on the formation of single multilayer thin wall and multi-channel single-layer plane with different tilt angles was carried out.The influence of scanning time interval and z-axis lifting height on the forming height,the effect of base surface inclination on the vertical precision of thin-walled and base surface,and the influence of transverse lap rate on the plane topography were also analyzed respectively.4.The tensile properties of 316 L laser cladding composite materials was studied,for which the fracture morphology and microstructure were analyzed.The results showed that the strength of specimens can be improved by heat treatment;in addition,the inclination angle of the base surface had little effect on tensile strength;Moreover,yield strength and plastic deformation,and the tensile strength of the joint of the mixed parts was higher than that of the adding material,and it satisfied the engineering application standard of the same material.