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我们用光学显微镜的明场法和暗场法对金属断口、零件表面的裂纹形态以及腐蚀斑坑等进行了对比观察,发现暗场下的成像效果优于明场,即使是粗糙或反光能力较差的表面也能获得明亮的视野。下面是应用暗场观察的几个实例。观察中使用倍率不超过400倍,物镜数值孔径不超过0.75。一断口观察1 疲劳断口(1)区域特征显示:由于疲劳导致失效的金属零件的断口,论其断裂过程有三个不同的区域:疲劳核心区,平坦光滑的疲劳区和粗糙的瞬断区。在暗场下其成像清晰,三个区域特征明显,见图1。
We use optical microscopy of the bright field method and the dark field method on the metal fracture, the surface of the part of the crack morphology and corrosion pitting were compared, and found that dark field imaging is better than the bright field, even rough or reflective ability Poor surface can also get a bright field of vision. Here are a few examples of dark field observations. Observed use of magnification does not exceed 400 times the objective numerical aperture does not exceed 0.75. A fracture view 1 Fatigue fracture (1) Regional characteristics show that there are three different regions of failure of the metal parts due to fatigue: fatigue core zone, flat smooth fatigue zone and rough transient zone. Its imaging is clear under the dark field, the three regional characteristics are obvious, see Fig. 1.