Research On The Preparation Technology Of Sialon/SiC Ceramic With The Properties Of Thermal Shock-wear Resistance

Aiming at the problem that Sialon/SiC ceramics`s properties of thermal shock-wearresistance and preparation，different percentages of SiC are adding in the samples on thebasic of Sialon composition to finish the experiment respectively in three sinteringtemperature; Aiming at the problem that in the process of practical application ceramicproducts both need thermal shock-wear resistance and wear resistance, the experiment usesdry pressing molding technology and flowing N2protection with no atmosphere pression todesign samples.Three removing plastic processes are designed to make sure the bestappropriate temperature.By analyzing the stereoscan photographs, energy spectrum of sialonceramics and XRD to study the influences to the microstructure of sialon,elementcompositions, phase compositions, sintering temperature,the content of SiC and heat treatmenttemperature; and the detecting of thermal shock-wear resistance experiment of Sialon samplesare designed both in the air and in the water.The results of removing plastic experiment show that the weight loss of each piece ofsamples is the most close to the content of PVB in each piece of sample at450℃,underwhich the weight loss of each piece of samples is so small that PVB is not removedcompletely,more pores will form in the samples which influence both the density and thethermal shock-wear resistance of the samples after calculation;on the contrary,over thetemperature the weight loss of each piece of samples is lesser and even the samples getweighter,which is caused byAlN oxidation.The sintering results show that the deformation of samples is small and there is nopowder conglutinated on the surface at1700℃and1750℃.The samples are successfullysintered with the flat sueface and good macro effect;At1800℃and1850℃the deformationof samples is bigger and there is powder conglutinated on the surface.Part of the samples melt.Partial melting samples are adhesion to the crucible that can`t be taken out,which results insintering unsuccessfully.The pictures of scanning electron microscope show that the air pores in the samplesdecrease with the content of SiC in different samples incresaing at1750℃,the densityincrease on the contrary; The columnar crystals of the samples increase as the content of SiCat the same time.The pictures of energy spectrum show that the composition of the columnar crystals are silimar to the sialon columnar crystal,according to which they are sialon columnarcrystals.The analysis of XRD show that sialon phase appears in all samples,which proves thatthe temperature1750℃is appropriate.The thermal shock-wear resistance test of samples show that the edge of M12cracks at1200℃in the air and the rest of the samples keep intact;All the samples crack from low tohigh as the content of SiC increasing at1400℃except the sample M52;All the samples crackat1500℃；In the water only the edge of the sample M12cracks at800℃；The center ofM12and M22crack but the edge of M32and M42crack at1000℃except the sample M52；All the samples crack at1100℃。Above all，the thermal shock-wear resistance of Sialon/SiCbenefits from the increasing of the content of SiC.