氧化铝基陶瓷材料断裂韧性的测量与评价

用压痕法和单边切口梁法测量了氧化铝基陶瓷材料的断裂韧性,对这两种方法所测得的结果进行了分析对比,确定了最适用的压痕法计算公式。研究发现,原料粉末的起始粒度对用压痕法计算材料KIC的最优公式选择并无影响,但对材料的断裂韧性及抗弯强度有不同程度的影响,亚微米第二相增强微米基体的材料综合力学性能最佳;TiN的加入使Al2O3-TiC基体材料的断裂韧性有所增加;在较小的压痕载荷下计算出的材料的断裂韧性值更接近实际;在用不同的公式计算同一材料的断裂韧性值时,断裂韧性值与压痕载荷之间有相似的关系曲线。

Measurement and Evaluation of Fracture Foughness of Alumina Matrix Ceramics

Fracture toughness of alumina matrix ceramics measured by indentation method and single edge notched beam specimen techniques were analyzed and contrasted, and the most suitable indentation method equation was confirmed. Results revealed that the fracture toughness and flexure strength of the materials were influenced at varied degree by the original granularity of the powders, which had no effect on the selection of the most suitable equation for calculating the fracture toughness of the materials by indentation method. The composite with micrometer matrix reinforced by sub-micrometer second phase had the best comprehensive mechanical properties. The addition of TiN increased the fracture toughness of Al2O3-TiC matrix material. The results measured with the applied lower indentation loads were closer to the fact. When different equations were used to calculate the fracture toughness of the same material, the fracture toughness values had the similar dependence on the indentation loads.