Study On Preparation And Properties Of Hollow Glass Microspheres

As a new type of spherical glass functional material,hollow glass microspheres(HGM),have broad application prospects in many fields because of their unique hollow spherical structures,which have light weight,high strength,low thermal conductivity and good thermal stability.Therefore,it is of great significance to study the preparation and properties of hollow glass microspheres.In this paper,using waste plate glass powder as raw material,the green bodies were prepared by spray drying progress,and then the hollow glass microspheres with good surface morphology were obtained by sintering green bodies with a self-made combustion furnace.The properties of hollow microspheres were characterized by means of DTA,SEM,true density meter and mercury injection meter.The main research contents are as follows:1.In the process of application,the mechanical properties of hollow microspheres have different requirements,especially the compressive strength.First of all,through the analysis and calculation of the theoretical compressive strength formula,it is found that the strength of hollow microspheres is related to the external diameter r,wall thickness h,young’s modulus E and other factors,but as a result of this experiment adopts the method cannot the outer diameter and wall thickness in direct control of the microspheres,so experimental design will be based on the sintering temperature,particle size distribution and chemical composition of research and analysis is determined to get a good morphology and performance.When CF700 is used as foaming agent,the sintering temperature of the green body is 850 °C.After screening,the maximum intensity of finished microspheres with particle size distribution between 40 and 80 meters can reach 6.67 mpa in fire.After adding auxiliary agents Mg SO4·7H2O and Al(NO3)3·9H2O into the green body,the compressive strength of the samples obtained after sintering at 850 °C can reach 7.05 MPa and 6.86 MPa respectively.In addition,a large number of structural defects were found on the surface of the ball wall of the microspheres during the experiment,and there was a big gap between the measured strength and the theoretical strength.Therefore,the characteristics and formation mechanism of various defects were simply analyzed and summarized by studying the formation process of the hollow microspheres.2.The preliminary experiments adding auxiliary agent can improve the compressive strength of microsphere,different level but to cause a decline in microsphere surface defects increase,floating rate,at the same time when the sintering temperature of the body and foaming agent does not match the increase in the number of the defect in the structure can also lead to sample the experiment through to the body for foaming agent’s formulation and raw material chemical composition optimization microsphere,the morphology and properties of the finished product.At the sintering temperature of 900 °C,1.0wt % CF700 and 1.5wt % ADC composite foaming agent were used,and Mg SO4·7H2O components were added,respectively.After sifting,the samples with diameters ranging from 40 to 80 and 80 to 120 had smooth surface and compressive strength of 8.43 MPa and 7.9 MPa,respectively.