Fatigue Crack Initiation and Propagation Behavior of Fiber Reinforced Metal (Sic/Al) at elevated temperatures

纤维增强金属 (Sic/Al) 在高温下的疲劳裂纹萌生和扩展行为

• 批准号: 62550070
• 负责人: HASEGAWA Norihiko
• 金额: $ 1.22万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1988
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62550070/
• 关键词: Fiber reiforced Metal; SiC Whisker; Aluminum cast alloy; Fatigue strength; Elevated temperature; 疲労き裂進展挙動; 疲労; 疲労き裂進展; 応力拡大係数

Fatigue tests were made on a random SiC whisker reiforced cast aluminum alloy (SiC/AC8A) over the temperature range from room temperature to 350 C. Fatigue crack initiation and propagation behavior were investigated.The fatigue strength of SiC/AC8A is superior to that of cast aluminum alloy AC8A at room temperature. Fatigue strength at 10^7 cycles at room temperature of SiC/AC8A is about 2 times that of AC8A.The number of cycles for crack initiation of FRM is about 600 times that of AC8A, is equivalent to 90% of the total fatigue life. the increase in the fatigue lives of FRM is owing to the increase in the number of cycles for crack initiation.The fatigue strength at 350 C of FRM is also larger than that of AC8A, but the rate of increase of FRM decreases to about 17%. The fatigue strength for 100h at 350 C of FRM is equal to that for 0.5h at 350 C. For FRM, times at elevated temperature does not have a marked effect.

对一种无规SiC晶须增强铸造铝合金（SiC/AC 8A）进行了室温至350 ℃的疲劳试验。研究了SiC/AC 8A复合材料的疲劳裂纹萌生和扩展行为，结果表明：SiC/AC 8A复合材料的室温疲劳强度优于铸造铝合金AC 8A，具有上级的疲劳强度。SiC/AC 8A复合材料的室温疲劳强度约为AC 8A的2倍，疲劳裂纹萌生循环次数约为AC 8A的600倍，相当于其疲劳总寿命的90%。FRM的疲劳寿命的提高主要是由于裂纹萌生循环次数的增加，其350 ℃的疲劳强度也高于AC 8A，但FRM的提高率仅为17%左右。FRM在350 ℃下100 h的疲劳强度与在350 ℃下0.5h的疲劳强度相当。对于FRM，在高温下的时间没有显著影响。