Study On The Performance Of Resin Coated Sand For The Casting Of Cylinder Body And Head

The thesis is based on the production of cylinder body and head of JiangHuai automobile company. After studying the performance of resin coated sand, we can get the following simple results:The resin coated sand A is rougher and more uniform and rounder, it belongs to the typical wind-sand, moreover its melt-point is lightly higher than B and C, as a result of this, it is preferable to be used as the priority of making the sand-core and to prevent the all kinds of defects from happening.The curing-temperature and curing-time have little effect on the gas-permeability property of the resin coated sand during the constant curing-temperature and the curing-time, which are between 200 degree centigrade and 250 degree centigrade and between 90 seconds and 140 seconds respectively. So it's not necessary to consider it when we make sure the parameters for the production of sand-core.The strengths of three kinds of resin coated sand all begin to increase until the utmost and then begin to decrease while changing the factors of curing. But it's necessary to control the time and the temperature strictly during the production, because B resin coated sand is sensitive to the curing-temperature and A is sensitive to the curing-time respectively.When their strengths all reach the peak, they begin to decrease while increasing the temperature or prolong the time. The curves of thermogravimetric analysis show that the above results are caused by the breakage of chemical links.The experiment of breaking the ranks and the thermogravimetric analysis show that the phenol formaldehyde resin begins to decompose when the temperature is above 500 degree centigrade, which make the sand-core break the ranks. When they are heated to 700 degree centigrade, the rates of breaking the ranks can reach 100 percent.The optimal curing-parameters of three kinds of resin coated sand are respectively that A is 230 degree centigrade and 110 seconds, B is 230 degree centigrade and 120 seconds, C is 220 degree centigrade and 110 seconds.