Study On The Technology Of Nylon Core Box For Sand Casting Based On Rapid Prototyping

Rapid Prototyping(RP) is an advanced manufacturing technology that has been drawing attention of researchers and manufactures in recent years.As a new advanced manufacturing technology,rapid prototyping and manufacturing has successfully realized the manufacturing of rapid prototype,now it was developing swiftly toward rapid tooling. One of the most widely used methods of RP in the world is Selective Laser Sintering(SLS).Now,Selective Laser Sintering of nylon composites is the focus in the world.The parts made of Selective Laser Sintering of nylon composites have high intensity,elasticity and endurance and suit for the function test.The content and result of this article are as follows.The technical parameters of sintering nylon composites were optimized on the bases of experiments,with the dimension precision and the sintered density being guideline.The best processing parameters and its influencing rule are got by the using of square error analysis method.The optimum sintering parameters include that laser power is 10W, preheating temperature is 90℃,scanning speed is 2000 mm·s^-1 and power bed depth is 0.15mm.And the casting core-box was sintered at the condition of best processing parameters.The major effect factors on part's precision are analyzed,and the mechanisms of shrinkage and distortion during SLS of PA are discussed.Composition of shrinkage, computation and the relationships between shrinkage and process parameters are discussed. After the prime cause and developing trend of distortion are illustrated,its solving measurements are proposed.The prototyping sintering part was soaked in different compositions of resin.The result showed that the precision and mechanical performance of the part had obviously been improved,and the best composition of resin had been confirmed.Through the SEM scanned experiment of the part section,the microstructure difference between fore-post-treatment and after-post-treatment was analyzed,the result showed the hole number reduce,the gap become small,and the dense increase.The casting core-box was sintering and soaked in resin,after testing all aspects,the capability had reached the satisfied level.Finally,the resin-bonded sand was chosen as the sand of core sand,and a great sizes, smooth sand core was successfully produced by the use of nylon core box.