Research On Design And Manufacture Of Injection Mold With Conformal Cooling Channel Based On Selective Laser Melting

At present,the cooling system of injection mold mainly relies on the traditional sprue which is formed by drilling straight hole and then plugging some parts of the opening.The inefficiency and uneven heat dissipation of such a cooling system make it hard to improve producing efficiency and product quality.However,the cooling channel fitting the surface can effectively shorten the cooling time and lead to greater efficiency.Moreover,the cooling channel fitting the surface would not generate cooling shrinkage and it can effectively reduce many problems like warpage,cracking,flaming,and so on due to its balanced distribution.However,because the shape of the cooling channel is extremely complex,it cannot be integrated processed by the traditional machining.Also it can lead to a lot of problems like poor sealing if the molds are processed independently and then fitted together.Here,selective laser melting technology(SLM)has the advantages of high degree of freedom of space,high processing precision,good surface quality,high forming density and excellent mechanical properties,and it can provide the possibility for the integrated molding and cooling mold.Over the past few years,the design and manufacturing of cooling injection mold based on selective laser melting molding technology have become a major research hotspot.In this paper,the main design and manufacture of a cooling fan with a cooling nozzle injection mold is regarded as the starting point.The main contents and conclusions are as follows:(1)A casual cooling injection mold was designed.The comparison on cooling time and buckling deformation of the production between the traditional straight cooling flow injection mold and follow-up cooling injection mold was completed by using Autodesk Moldflow MFI and Autodesk Simulation CFD.The results show that the cooling time of the injection mold is 36% shorter than that of the traditional straight channel injection mold,and the total deformation of the injection molded product ion is reduced by 56%.(2)A cooling channel with the injection mold core was printed by advanced selective laser melting equipment EOS M 280 and its molding quality was tested.The results show that all the structural features including the follower flow can be formed normally.The surface roughness is Ra 10 ?m and the average hardness is 35.7HRC,which does not meet the requirements of industrial application.(3)After the heat treatment,the average hardness of the core is increased to 50.74 HRC,which meets the requirements of the hardness of the injection mold.The surface roughness of the molding surface of the injection mold can reach Ra 0.2 ?m;the surface roughness of the parting surface can reach Ra 1.6 ?m,and the surface of the mold is bright and completely free from trachoma.It can meet the actual industrial needs.