The Study In Precision Cold Bending Forming Method Of Metal Micro-groove Array Curved Surface

The metal micro-structure curved surfaces have the functional characteristics of drag reduction,shock absorption,antibacterial.At present,the processing of micro-structure functional surfaces mainly depends on laser,chemical etching,plasma beam and other processing technologies.However,it is difficult to control the shape accuracy.Generally,the multi-axis CNC machining technology is used for the processing of micro-structure curved surfaces,but the efficiency is extremely low and it is difficult to achieve the mass production.The injection molding forming is mainly used for plastic materials with low hardness and no high temperature resistance,and the high temperature melting molding of metals will bring about problems such as high energy consumption.Therefore,based on the spatial deformation processing of the micro-groove array plate,the cold bending rapid forming method of metal micro-groove array curved surface is proposed.The characteristic is that it does not require complex curved micro-groove metal core,but predict the structural deformation of micro-groove bending to compensate the shape and size deformation of micro-groove,and realize the rapid precision forming of micro-groove array curved surface.First,the high-precision micro-groove array on the cemented carbide core surface was processed by the micro-grinding technology developed early,and it was used for cold pressing micro-forming of the micro-groove array plane plate.The experimental results show that the grinded micro-groove array was angle of 90°,120°and depth of 200?m,the dimension and shape error were less than 5%and 0.8%,respectively,and the maximum surface roughness R_awas 280 nm.Then,the mechanism of cold pressing micro-forming of the metal micro-groove array was analyzed through experiments.It was found that the forming angle of the micro-groove was consistent with the micro-groove of the core,and the forming height increased with the decrease of the hardness of the material,the increase of the maximum cold pressing pressure and the decrease of the cold pressing speed.The 1060 and 5052 aluminum alloys with lower hardness could reach approximately 100%filling rate in 2 minutes.Moreover,and the surface roughness R_a was lower than that of the core.Then,the curvature radius,plate thickness parametric models of micro-groove array curved surface bending were established,and the orthogonal experiment of structural parameters affecting micro-groove bending deformation was carried out.It was found that the deformation of micro-groove occurred at the same time as the curved surface forming.the load of the workpiece increased linearly at this stage,and remained stable after reaching the inflection point.The micro-groove formation could be judged by the change of the load curve.The micro-groove angle increased,the depth decreased,and the curvature radius of the die and the thickness of the sheet had the greatest influence on the deformation.And the micro-groove bending forming was simulated by finite element simulation.The simulation results of 1060and 5052 aluminum alloys could accurately match the test results by multiplying the simulation parameter characterization coefficients.The profile error of the curved surface was less than 15?m after bending.Finally,according to the changing of micro-groove angle,an empirical prediction model of micro-groove deformation was established.According to the design and compensation of the prediction model,the error between the size of curved micro-groove and the expected value were less than 5%and 3%respectively after the micro-groove plate bending into spherical and ellipsoid surface.And the technical achievements were applied to the cold pressing production equipment of the enterprise.The micro-groove array could be cold pressed on the complex curved surface of 15#steel within one second,and the micro-groove array were complete,no burrs and smooth.