Study On Gradation Method And Thermal Expansion Coefficient Detector Design Of Quartz Sand Resin Mineral Composites

RMC(resin mineral composites)is a new type of environmentally friendly composite material casted at room temperature,using natural mineral particles as the aggregate,and organic resin as the binder.In recent years,RMC is widely used in the manufacture of high speed and precision machine tools,electronic and the foundation and bed of medical equipment,with its excellent damping performance,complex shape forming ability and good corrosion resistance.Compared with the traditional foundry iron machine tool bed,RMC is still insufficient,low static strength and large thermal expansion coefficient,to a large extent,limit the wide application of this material.In this article,the epoxy resin is used as the binder,the quartz sand as the aggregate,aggregate gradation is based on the particle interference theory,and the key research objects is the formula preparation process for reducing the thermal expansion coefficient of the RMC material and optimizes the gradation parameters by numerical simulation and experimental verification.Analyze the factors affecting the coefficient of thermal expansion of RMC based on Levin's prediction model.The results show that using aggregates and resin with low coefficient of thermal expansion,reducing the proportion of resin could reduce the coefficient of thermal expansion of RMC.First of all,reducing the amount of resin used in artificial stone materials is the most effective method,followed by the use of low thermal expansion resin systems.(1)Based on Levin's prediction model,a theoretical analysis of the factors affecting the coefficient of thermal expansion of artificial stone materials is made.By lowering the coefficient of thermal expansion of aggregates,using resins with lower thermal expansion coefficients,and reducing the proportion of resin mentioned,the thermal expansion of artificial stone materials can be reduced coefficient.First,reducing the amount of resin used in artificial stone materials is the most effective method,followed by the use of low thermal expansion resin systems.(2)Based on the particle interference theory,designed quartz sand aggregate gradation scheme through the concept of filling ratio,completed the bulk density testing experiment for different filling ratio.Chose the gradation with the smallest accumulation porosity as the best gradation.(3)Establish a liquidity theory prediction model based on the theoretical analysis of the fluidity of the mixture,and the rationality of the theoretical prediction model was verified by performing the slump experiment.(4)In view of the different cross-sectional dimensions of the test specimens for the thermal expansion coefficient of quartz sand RMC under different standards,in this article,it assumes that the particle size of all aggregates form the aggregate framework which is most closely packed,and the cross section of the test specimen is square.Calculate the size of the final test sample by simulating the range of the area ratio of the aggregate when the cross-sectional length is 3-4 times the aggregate size.and the final test sample size was determined by the results.Completed the structural design of a new type of independent heating thermal expansion coefficient detector capable of testing the sample which length is more than 100 mm.