AFM/SEM観察に基づく疲労き裂伝ぱ機構の研究 : (第1報, (110)[001]Fe-3.2%Si単結晶におけるストライエーション形成域での検討)
AFM/SEM観察に基づく疲労き裂伝ぱ機構の研究 : (第1報, (110)[001]Fe-3.2%Si単結晶におけるストライエーション形成域での検討)
复制标题
基于AFM/SEM观察的疲劳裂纹扩展机制研究：（第1次报告，（110）[001]Fe-3.2%Si单晶中条纹形成区域的研究）
DOI：
10.1299/kikaia.66.78
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Kenji Higashida
中科院分区：
文献类型：
--
作者：
Yasuji Oda;Y. Furuya;Hiroshi Noguchi;Kenji Higashida
采用适合条纹形成取向的Fe-3.2% Si单晶薄板进行了疲劳裂纹扩展试验。为了弄清裂纹扩展的机理，利用原子力显微镜和扫描电镜对疲劳循环加载和卸载过程中裂纹尖端附近滑动的行为进行了现场观察，并对断口表面进行了分析。得到如下结果：(a)一对断裂面上的条纹显示峰谷匹配，而不是任何形式的对称匹配。(b)条纹剖面显示浅波纹。(c)加载过程中，裂纹尖端的一对集中滑动交替激活，导致裂纹张开，从而导致裂纹推进。(d)卸载过程中，导致裂缝闭合的反卡瓦以分布的方式被激活。(e)在高得多的生长速率下，观察到由若干交替滑移引起的开闭过程。(f)真空环境有利于许多交替滑移：这是在真空中观察到断口表面没有明显条纹的原因之一。结果，在上述观察的基础上，提出了疲劳裂纹扩展的基本模型。
Fatigue crack growth tests were carried out on thin plates of a Fe-3.2% Si single crystal with an appropriate orientation for striation formation.To clarify the mechanism of crack growth, behaviors of slips near a crack tip during the loading and unloaaing parts of a fatigue cycle were observed in-situ with an atomic force microscope and a scanning electron microscope and fracture surfaces were also analyzed.Following results are obtained.(a)Striations on a pair of fracture surfaces reveal peaks to valleys matching other than any kinds of symmetrical matching.(b)Profiles of striations reveal shallow ripples.(c)During loading, a pair of concentrated slips activated alternately at a crack tip lead to crack opening and thus crack advance.(d)During unloading, reverse slips which lead to crack closing are activated in a distributed manner.(e)At much higher growth rate both opening and closing processes by a number of alternating slips are observed.(f)Vacuum environment facilitates a number of alternating slips:this is one of the causes for observing no distinctive striations on fracture surfaces in vacuum.In result, a fundamental model for fatigue crack growth is proposed on the basis of observations mentioned above.