BAS粘接碳化硅材料的性能

Preparation and properties of BAS/SiC complex phase ceramic materials

采用原位生成钡长石为烧结助剂,研究BAS/SiC复相陶瓷的低温无压液相烧结工艺,制备高致密度的陶瓷材料。通过XRD、SEM及力学试验机等研究烧结温度、BAS含量对复相碳化硅陶瓷的致密化、组织结构及力学性能的影响。结果表明:在1800℃温度下原位生成了BAS相,运用无压液相烧结法制备出了密度达到3.2g/cm3的BAS/SiC复相陶瓷;陶瓷中BAS以六方结构析出、SiC颗粒均匀分布;烧结温度不宜超过1800℃,温度过高将促使碳化硅颗粒长大,损伤陶瓷材料抗弯强度和断裂韧度;当复相BAS/SiC陶瓷中BAS质量分数为30%时,弯曲强度达到413MPa,模量达到210GPa,断裂韧度达到5.03MPa.m1/2。

Celsian was synthesized in situ and was used to sinter silicon carbide. The low temperature pressureless liquid sintering process for BAS/SiC complex phase ceramics was studied, and ceramic materials with high density were prepared. The effect of sintering temperature and content of BAS on density, structure and mechanical properties of the ceramics were investigated. The densification and microstructures of BAS/SiC ceramics were observed by scanning electron microscope. The crystalline phase of the composite ceramics was identified by X-ray powder diffraction. The results show that celsian is synthesized at the temperature of 1800 ℃, 3 and BAS/SiC ceramics are prepared with density of 3.2 g/cm . BAS is precipitated in hexagonal structure, and SiC particles are distributed uniformly in the composite ceramic. The flexural strength and fracture toughness of composite ceramics are decreased due to grains growth while the sintering temperature is above 1800 ℃. When the mass content of BAS reaches 30%, the typical flexural strength, elastic modulus and fracture toughness of the pressureless sintered BAS/SiC ceramics are 413 MPa, 210 GPa 1/2 and 5.03 MPa m at room temperature.