【摘要】 通过燃烧合成结合热等静压的方法,在100MPa氮气压力下制备了h-BN陶瓷,理论计算了稀释剂h-BN的质量分数对反应的燃烧模式和燃烧温度的影响,通过实验分析了陶瓷的力学性能和稀释剂质量分数的关系,随着稀释剂质量分数的增加,产物的相对密度、抗弯强度和断裂韧性先升高然后有所降低,在稀释剂质量分数为67％处有最大值,其分别为1.41g/cm³、41MPa和1.28MPa·m^1/2,通过XRD分析了产物的相组成,SEM断口显微照片发现,h-BN呈层片状分布,其断裂方式为沿晶断裂。更多还原

【Abstract】 h-BN ceramics were fabricated by means of SHS-HIP under nitrogen pressure of 100MPa. The effects of h-BN dilution content on combustion model and adiabatic temperature were calculated theoretically. The relationship between mechanical properties and dilution content were discussed on the base of experimental results. The relative density, bending strength and fracture toughness of h-BN ceramics have peak value in the dilution content of 67%, respectively, 1.41g/cm³, 41 MPa and 1.28MPa·m^1/2. Phase composition is analyzed by XRD, and SEM fractographs show that the h-BN grains appears layered flake and the fracture mode is intergranular crack.更多还原