Besserer Hans-Bernward, Gerstein Gregory, Maier Hans Jürgen, Nürnberger Florian
Institut Für Werkstoffkunde (Materials Science), Leibniz Universität Hannover, An der Universität 2, Garbsen, 30823, Germany.
ZFM - Centrum of Solid State Chemistry and New Materials, Leibniz Universität Hannover, Callinstraße 3a, Hanover, 30167, Germany.
Microsc Res Tech. 2016 Apr;79(4):321-7. doi: 10.1002/jemt.22633. Epub 2016 Feb 8.
To investigate ductile damage in parts made by cold sheet-bulk metal forming a suited specimen preparation is required to observe the microstructure and defects such as voids by electron microscopy. By means of ion beam slope cutting both a targeted material removal can be applied and mechanical or thermal influences during preparation avoided. In combination with scanning electron microscopy this method allows to examine voids in the submicron range and thus to analyze early stages of ductile damage. In addition, a relief structure is formed by the selectivity of the ion bombardment, which depends on grain orientation and microstructural defects. The formation of these relief structures is studied using scanning electron microscopy and electron backscatter diffraction and the use of this side effect to interpret the microstructural mechanisms of voids formation by plastic deformation is discussed. A comprehensive investigation of the suitability of ion beam milling to analyze ductile damage is given at the examples of a ferritic deep drawing steel and a dual phase steel.
为了研究通过冷板料-体积金属成型制造的零件中的韧性损伤，需要一种合适的试样制备方法，以便通过电子显微镜观察微观结构和诸如孔隙等缺陷。通过离子束倾斜切割，既可以进行有针对性的材料去除，又可以避免制备过程中的机械或热影响。与扫描电子显微镜相结合，这种方法能够检测亚微米范围内的孔隙，从而分析韧性损伤的早期阶段。此外，离子轰击的选择性会形成一种浮雕结构，该结构取决于晶粒取向和微观结构缺陷。利用扫描电子显微镜和电子背散射衍射研究了这些浮雕结构的形成，并讨论了如何利用这种副作用来解释塑性变形导致孔隙形成的微观结构机制。以铁素体深冲钢和双相钢为例，对离子束铣削分析韧性损伤的适用性进行了全面研究。
