Fracture of Polycrystalline MgAl2O4
Fracture of Polycrystalline MgAl2O4
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DOI：
10.1111/j.1151-2916.1980.tb09847.x
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发表时间：
1980-11
影响因子：
3.9
通讯作者：
R. L. Stewart;R. Bradt
中科院分区：
文献类型：
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作者：
R. L. Stewart;R. Bradt
在1400°C下测量了化学计量比多晶MgAl 2 O 4的断裂韧性作为晶粒尺寸和温度的函数。室温断裂韧性与报道的单晶值相当。未检测到粒度的影响。观察到KIc=f（T）的两个区域，均显示KIc随T增加而减小。在低温区，断裂方式为穿晶和沿晶混合断裂。Δ 10−4 MN/m3/2°C（dK 10 dT）的降低主要由dE/dT决定。在高温区，T >900°C，dK 10 dT的下降幅度更大，为10−3 MN/m3/2°C，断裂特征完全是沿晶断裂，表明晶界过程占主导地位。
The fracture toughness of stoichiometric polycrystalline MgAl2O4 was measured as a function of grain size and temperature to 1400°C. The room temperature fracture toughnesses are comparable to reported single-crystal values. No effect of grain size was detected. Two regions of KIc=f(T) were observed, both showing a decreasing KIc with an increasing T. In the low-temperature region, fracture is of a mixed mode, transgranular and intergranular character. The ∼10−4 MN/m3/2°C (dK10dT) decrease is governed primarily by dE/dT. The high-temperature region, T >900°C, has a much larger dK10dT decrease, ∼ 10−3 MN/m3/2°C, and a fracture character that is totally intergranular, suggesting dominance by grain-boundary processes.