Study Of Micromilling Parameters And Processes For Miniature Thin Walls

Recently,with the development trend of precision,lightweight and miniaturation in machinical fields,miniature parts have been widely used in many areas such as aerospace,medical treatment,national defense,communication,electron,etc.The miniature thin walls with small volume and light mass are the structures or basic features of many mini parts and occupy the unsubstitutional status in many industries.Owing to the structural features of thin walls,traditional machining is easy to cause the larger stress and temperature destortion and affects the machining precision.Micro-high-speed milling technology has many advantages such as small loads,high machining precision and wide processing ranges,etc.Using micromilling technology to fabricate miniature thin walls and investigating the parameters and the processes in the micromilling thin wall process have become one of the most cutting-edge in micromilling field.Aming at materials brass and stainless steel,the influences of parameters and processes on the surface quality and dimensional precison of miniature thin walls are stuied by the method of combined simulations and experiments in this article.Firstly,the finite element simulation models are established and the micromilling simulated single-factor experiments are conducted for materials brass and stainless steel.The enfluence laws of key paraments of micromilling processes on milling forces are obtained for the two meterals by the results anlyses of simulated milling forces.Then,based on the simulation results,the single-factor micromilling experiments and verification,orthogonal optimization and thin wall micromilling experiments are successively conducted for material brass.By single-factor experiments,the effect laws of key micromilling parameters including feed engagement,axial depth of cut and radial depth of cut on miling forces,thin-wall surface roughnesses and dimensional errors are obtained.By orthogonal optimization experiments,the influence order of milling parameters on the three indexes and the optimal micromilling parameters combinations are analyzed respectively.In thin walls micromilling experiments,the constant-height experiments and the constant-parameters experiments are designed and conducted.It reveals the relationships between axial feed times and thin-wall dimensional errors under the conditions of constant parameters and constant thin wall height.Finally,based on the experimental results and micromilling flow of miniature thin walls for brass material,the disign,conduct and analysis of single-factor,orthogonal optimization and thin wall fabrication experiments for micromilling miniature thin walls of stainless steel are successively carried out.The thin-wall micromilling results for the two materials are analyzed synthetically.The conclusions obtained are as follows.The variation trends of thin-wall dimensional error and surface roughness can be reflected indirectly by that of milling forces.Axial depth of cut has the largest effect on the machining quality of thin walls.The influence law of radial depth of cut on each index changes with the diffent milling ways.For the height constant miniature thin walls,there exists the optimal axial feed times for achieving the smallest dimensional errors of thin walls.In this paper,the research results of micromilling experiments for miniature thin walls have certain guidance and reference significance for the actual processing of miniature thin walls.Meanwhile,the research method on micromilling parameters and process optimization proposed in this paper can be applied to the micromilling parameters and process optimization for miniature thin walls made of other materials.