R‐Curve Behavior and Strength for In‐Situ Reinforced Silicon Nitrides with Different Microstructures
R‐Curve Behavior and Strength for In‐Situ Reinforced Silicon Nitrides with Different Microstructures
复制标题
不同微观结构的原位增强氮化硅的 R 曲线行为和强度
DOI：
10.1111/j.1151-2916.1992.tb07197.x
复制
发表时间：
1992
影响因子：
3.9
通讯作者：
Siu‐Ching Lui
中科院分区：
文献类型：
--
作者：
Chien;Dong‐Joo Lee;Siu‐Ching Lui
使用格里菲斯方程和压痕断裂力学表征名义上成分相同的两种原位增强氮化硅 A 和 B 的 R 曲线。这些 R 曲线针对细晶粒氮化硅进行校准，细晶氮化硅具有已知的 V 形缺口（长裂纹）韧性和几乎平坦的 R 曲线行为。氮化硅 A 具有较粗的微观结构和较高的人字形缺口韧性，如果裂纹尺寸小于~200 μm，则其对裂纹扩展的抵抗力低于氮化硅 B。这些结果与压痕强度测量结果一致，该测量显示两种材料在压痕载荷为 49 至 98 N 之间时存在强度交叉，低于交叉点 A 的强度较低。使用短裂纹的弹性桥接模型和长裂纹的拉拔模型来解释增韧行为。讨论了 R 曲线特性对设计的影响。
R-curves for two in-situ reinforced silicon nitrides A and B of nominally the same composition are characterized using the Griffith equation and indentation fracture mechanics. These R-curves are calibrated against fine-grained silicon nitrides which have a known chevron-notch (long-crack) toughness and with a nearly flat R-curve behavior. Silicon nitride A, with its coarser microstructure and higher chevron-notch toughness, shows lower resitance to crack growth than silicon nitride B if the crack size is less than ∼200 μm. These results are consistent with the indentation–Strength measurements which show a crossover of strength between the two materials at an indentation load between 49 and 98 N, and below the crossover A has a lower strength. The toughening behavior is explained using an elastic-bridging model for the short crack, and a pullout model for the long crack. The effects of R-curve properties on design are discussed.
影响因子：
5.4
作者：
NEWMAN, JC;RAJU, IS
通讯作者：
RAJU, IS