Static Fatigue Limit for Sintered Silicon Carbide at Elevated Temperatures
Static Fatigue Limit for Sintered Silicon Carbide at Elevated Temperatures
复制标题
高温下烧结碳化硅的静态疲劳极限
DOI：
10.1111/j.1151-2916.1983.tb10560.x
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发表时间：
1983
影响因子：
3.9
通讯作者：
R. E. Tressler
中科院分区：
文献类型：
--
作者：
E. Minford;D. Kupp;R. E. Tressler
采用改进的静态加载技术估算静态疲劳极限，研究了氧化和温度对烧结碳化硅静态疲劳极限K_（10）的影响。对于经机械加工的未氧化烧结碳化硅，静载荷时间为4 h，1200°时K10× 2.25 MPa * m1/2，1400°C时K1.75。在1200°C下氧化10 h后，在非氧化环境中测试时，K10在1200° C下降至1.75 MPam 1/2，在1400°C下降至1.25 MPam 1/2。对于在空气中进行的测试，在1200°C下获得了类似的结果。静态疲劳极限以下的加强趋势似乎是由于在裂纹尖端区域的应力的塑性松弛的粘性变形涉及氧化材料的氧化物晶界相，并可能在未氧化材料的情况下，扩散蠕变变形。
The modified static loading technique for estimating static fatigue limits was used to study the effects of oxidation and temperature on the static fatigue limit, K10 for crack growth in sintered silicon carbide. For as-machined, unoxidized sintered silicon carbide with a static load time of 4 h, K10× 2.25 MPa * m1/2 at 1200° and ∼1.75 at 1400°C. On oxidation for 10 h at 1200°C, K10 drops to ∼1.75 MPam1/2 at 1200° and ∼1.25 at 1400°C when tested in a nonoxidizing ambient. Similar results were obtained at 1200°C for tests performed in air. A tendency for strengthening below the static fatigue limit appears to result from plastic relaxation of stress in the crack-tip region by viscous deformation involving an oxide grain-boundary phase for oxidized material and, possibly, diffusive creep deformation in the case of unoxidized material.