| Three-dimensional parts directly manufacturing based on laser cladding technology,namely the DLF technology(laser direct manufacturing technology),is an advanced manufacturing technology which promotes manufacturing by designing products without moulds and tools.Three-dimensional CAD/CAM data are only needed to be imported into the control system of equipment,the compact metal parts can be directly made according to the imported files with the help of coaxial powder laser cladding processes,indicating a vast industrial application prospect.EPB systematic(Electronic parking brake system)transmission nut in the manufacturing process is one kind of complex but immature part.Weak abrasive resistance,short lifespan and expensive price are the reason why further researches are needed to improve the situation.This assay takes the process of RCF101(Iron alloy)alloy molten formed part as the research object,and is aim to ensure the quality of surface morphology and forming precision of formed parts,and to achieve the aim to reduce the amount of internal pores and cracks.The purpose is to get equally distributed structure and improve the quality of forming parts.This paper has accomplished the systematic experiment studies and mechanism analyses.The process of formed part do not need moulds,can definitely reduce coast and improve efficiency.So the study of laser cladding transmission nut forming technology has a certain practical significance.This paper did some research work to solve the problems,the concretely work are three parts,which I will explore in the following essay.(1)The article has studied some process parameters such as laser power,scanning speed,powder feeding velocity etc.First,this essay got experimental data via orthogonal experimental of cladding single-channel monolayer melting.Then analyzed the impact of changing comprehensive process parameters on the weld width and h/H.Moreover,the impact on weld width of one in three parameters regular change under condition that the rest two parameters one staying constant and another irregularly changing,and the impact on weld width and h/H of the comprehensive change process parameters.Finally,through integrating various kinds of experimental results,the essay concluded one set of best process parameters aiming at cladding RCF101(Iron alloy)alloy molten formed part:the laser power is 450W,scanning speed is 0.006m/s,powder feeding velocity is 0.9r/min.(2)In order to achieve further study of the forming process and guarantee the cladding process stability.The article has studied lap rate and the overlap between layers.First,for lateral overlap rate,the experiment used five different overlapping rate during experiment,then analyzed the molten layer surfaces,cross-section morphologies,tissues.As a result,the best final distance between the fusions is 1.4mm.According to the transverse overlapping ratio,the essay studied the longitudinal lap ratio.Through the experiment of three groups of different increments of z axis,and analyzed the cross-section morphologies,melting layer surface collapses,tissues,made qualitative analyses on the z axis increments and determined the z axis quantity as 0.5mm.Finally,the paper analyzed the forming parts of the single-layer overlap and put forward the further optimization scheme,and the way of overlap between layers,including formed parts surface morphologies and qualities,internal tissues and the heat affected zones,cross section porosities,cracks and interlayer scanning methods and further optimizations and so on,which under different overlap ways between various layers.(3)The article has analyzed the transmission nut forming technology feasibility.First,this essay used scanning ways and conclusions which obtained from former chapters to optimize scanning way,the entire parts scanning track and interlayer lap optimization.Then observed the cladding forming quality during the process,real-time adjustment of process parameters.Finally,measured the quality and accuracy of the forming. |
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