Research Of The Material And Manufacture Technique Of Selective Laser Sintering Of Resin Coated Sand

The SLS resin coated sand cores after post-solidified can be cast directly.This way can save more time and energy.The formers study the fields of post-solidifying of resin coated sand and rapid cast very little.So these fields will be discussed in my paper. The resin coated sands with different resin content and particle size are selected as study targets.One kind of these resin coated sands is selected to do sintering experiments.The bend strength is test.The sintering parameters are confirmed. The samples of different kind of resin coated sand with different resin content are made on SLS.Then they are post-solidified in different temperature.The bend strength and tensil strength of these samples is test.The kind of resin coated sand and the post-solidifying temperature is confirmed by analyzing the bend strength and tensil strength.The metal parts are made by way of integrating the SLS and cast.Sand cores are sintered.The metal parts are cast.Then the sintering precision is discussed.The precision between the parts and sand cores and the precision between the design and metal parts is also discussed.The sintering parameters and post-solidifying parameters are confirmed by testing the samples'strength.Sintered thickness is 0.3mm.Preheat temperature is 90℃.Scan speed is 2000m/s.Laser power is 35W.Scan space is 0.1mm .Post-solidifying temperature is 170℃.The strength is increased by 10 times after post-solidifying.The type of resin coated sand is confirmed by analyzing the air releasing amount and the different mechanical performance of resin coated sand in different temperature.When the content of resin is 3.5% and the particle size is 100/50,the integration property of the sand is excellent.The sand cores of the wheel are measured and the sinter precision is±0.901%.Cast parts are also messured.The precision between sand cores and cast parts is 0.543%.The precision between design and cast parts is 1.406%.The tolerance rank of cast parts is CT9. According to the experiment,we can get that the strength of the sand cores can be increased after post-solidified and the sand cores can be cast.So the way pointed out in my paper is practicable.