Research On Digital Manufacturing Process Of Centrifugal Pump Body Based On Additive Manufacturing Technology

As a typical additive manufacturing technology,selective laser sintering has the characteristics of high material utilization,short process flow,and random modeling.Combining this technology with traditional sand casting will help break through the limitations of traditional casting and promote its development towards smart,intelligent,The development of flexible and green casting.This article takes a certain type of pump valve parts as an example to discuss the application of selective laser sintering technology in the rapid manufacturing of complex thin-walled parts.The research mainly includes the following aspects:(1)Analyze the structure of the parts,design the casting process of the pump body,and use the finite element software ProCAST to simulate and analyze the designed scheme to verify the rationality of the scheme.(2)Analyze the limitations of the traditional casting process,and combine the advantages of additive manufacturing technology with high flexibility and arbitrary modeling to optimize the sand structure of the pump body: through contour cutting,sand hollowing,support design and other means to achieve lightweight sand,The material saving rate reaches76.2%;the integrated sand mold design avoids all kinds of casting defects caused by splicing after block remaking;the design of the conformal air passage ensures smooth exhaust.(3)Analyze the sintering mechanism of coated powder materials,and study the effects of laser power,scanning speed,and sand surface temperature on the sintered lines.The greater the laser power,the lower the scanning speed and the higher the sand surface temperature.The width and width of the sintered lines The greater the depth,and the more significant the effect of laser power on line sintering.By studying the effects of laser power,scanning speed,filling gap,and printing layer thickness on the performance of sintered parts,it is found that the higher the power,the slower the speed,the smaller the gap,the thinner the layer thickness,the more severe the sintering of the part,and the more resistant it is.The tensile strength experienced a process of first increasing and then decreasing,indicating that too high energy input would lead to resin carbonization and damage the connection effect.The secondary sintering gradually increased with the increase of the sintering energy density.(4)Analyze the curing mechanism of sand mold post-treatment,and study the effect of holding time and temperature on the mechanical properties of sand mold.By observing the impact of different gas atmospheres on the tensile strength of the sample,it is found that a proper amount of water vapor and formaldehyde will help the resin to further polycondensate.Reaction to improve the mechanical properties of the sand mold.It was proposed to use organic solvent infiltration to improve the post-treatment process,and it was found that the use of alcohol and isopropanol can improve the fluidity of the resin,resulting in the formation of a larger-scale resin neck between the grit.(5)Analyzed the mechanism of the two types of inorganic binders,through the filler,curing agent,modifier,expansion agent,etc.to modify the binder,the use of modified binder can achieve the broken sand mold repair.(6)Refer to the above process for sand mold manufacturing,post-treatment strengthening and repair,and check that the sand mold size is qualified through three-dimensional comparison.Finally,pouring was performed to obtain pump body parts with good surface quality and qualified size,which verified the feasibility of the technical route.