The Optimization Of Sand Mold 3D Printing Process Parameters And The Experimental Research On The Problem Of Push Marks

With the constant update of the era and technology,the traditional casting industry needs to inject fresh blood.3D printing provides a new molding method for sand casting,it meets the demand of production and research of single small batch and complex forming parts,and it has an extensive development prospect.Process parameters are important factors that affect the performance of the sand mold(core)within the 3D printing.This paper is based on three-dimensional printing(3DP)to investigate the influence of process parameters on sand mold(core)performance.SPSS and MATLAB software are used to fit and screen the data to obtain the best printing parameters and casting verification.This paper explores the problem of pushing marks in ceramsite sand and the probability of push marks are reduced by changing process parameters.The influences of four process parameters of namely layer thickness,X resolution,activator and re-coater speed on the bending strength,tensile strength,gas evolution and ignition loss about sand mold(core)are studied.The results of four groups of experiments show that within the adjustable range of parameters,the best parameters of the strength of the four experiments are: layer thickness 0.24mm;the X resolution 0.08 mm;the activator agent is 0.14%;and the re-coater speed ranges is 140-160 mm/s.The process parameters with the best performance and meeting the actual production requirements are selected by SPSS and MATLAB software.The best combination of parameters is as follows,the thickness is 0.25 mm,the X resolution is 0.09 mm,the activator agent is 0.14% and the re-coater speed is 120 mm/s.The ladder-shaped sand mold and cylinder head are printed and poured under this set of process parameters and great surface quality of the forming part is obtained.The effects of drying time,drying temperature and storage time on the performance of 3D printed sand mold(core)are studied.The experimental results show that the strength of the sample reaches its maximum when the drying time ranges from 0.5 h to 1h and the drying temperature ranges from 70 ℃ to 80 ℃.Sample placement time increases from one day to 30 days,the strength of 3DP printed sand mold(core)do not decrease significantly with the increase of the placement time.The reasons why the bottom of the ceramsite sand is prone to push marks when printed by 3DP was explored.It is verified through experiments that increasing the layer thickness and re-coater speed can reduce the probability of push marks.In this paper,through the above several aspects of research,the best process parameters combination of 3DP printed sand mold(core)is obtained,and the cylinder head with surface quality up to the requirement is poured successfully.The effects of drying time,drying temperature and storage time on the properties of sand mold(core)are obtained,meanwhile the probability of push marks is reduced by changing process parameters for ceramsite sand.