Insights into the Correlation between Residual Stresses, Phase Transformation, and Wettability of Femtosecond Laser-Irradiated Ductile Iron

Nanomaterials

Andreas Otto¹  Dhiraj Kumar¹  Gerhard Liedl¹  Werner Artner² 

[1] Institute of Production Engineering and Photonic Technologies, TU Wien, 1030 Vienna, Austria;X-ray Center, TU Wien, 1060 Vienna, Austria;

关键词: femtosecond laser;    wettability;    phase change;    residual stresses;    EBSD;    TEM;   

DOI  :  10.3390/nano12081271

来源: DOAJ

【 摘 要 】

Despite numerous studies on the wettability behavior of ductile iron after ultrafast laser structuring, the correlation between the phase change due to the interaction with an intense pulse and wettability is not yet well understood. In the present work, phase transformations of ductile iron substrates after femtosecond laser irradiation are investigated and correlated with the wettability behavior. Laser parameters such as fluence (F), cumulative fluence (CH), number of pulses (N), and scan speed were varied to produce hierarchical structures with different morphologies and phase concentrations. Our outcomes indicated that substrates with higher concentrations of austenite in the absence of hierarchical structures have a superhydrophilic nature despite being stored in an ambient atmosphere for several days and the application of a vacuum process. In addition, we measured the concomitant residual stresses after laser irradiation using the X-ray diffraction (XRD) method and established a relationship with the doses of CH and induced micro/nanostructures. Transmission electron microscopy (TEM) revealed that laser-structured surfaces are covered with oxides; moreover, phase transformation occurs at the near-subsurface layer.

【 授权许可】

Unknown