Surface and microstructure investigation of picosecond versus femtosecond laser pulse processed copper

SURFACE & COATINGS TECHNOLOGY

卷:409

Article

Anderson, Mark¹  Ediger, Aaron²  Tsubaki, Alfred²  Zuhlke, Craig²  Alexander, Dennis²  Gogos, George¹  Shield, Jeffrey E.¹ 

[1] Univ Nebraska Lincoln, Dept Mech & Mat Engn, 900 N 16th St, Lincoln, NE 68588 USA

[2] Univ Nebraska Lincoln, Dept Elect & Comp Engn, 900 N 16th St, Lincoln, NE 68588 USA

关键词: Picosecond;    Femtosecond;    Laser processing;    Layered microstructure;    Copper;   

DOI  :  10.1016/j.surfcoat.2021.126872

来源: Elsevier

【 摘 要 】

A comparison is made between the self-organized surface features that form on copper using femtosecond versus picosecond laser pulses. Modification of material surfaces (like metals and dielectrics) have shown to affect the properties for applications including enhancing heat transfer and producing anti-corrosive or antibacterial surfaces. Femtosecond laser surface processing is a precise and repeatable technique to produce uniform selforganized quasi-periodic structures on the surface for most metals. However, it is difficult to produce uniform quasi-periodic structures on noble metals (e.g. copper). Using femtosecond pulses in the processing of copper results in non-uniform structure formation with areas that have little to no mound development. Lengthening the pulses from femtoseconds to picoseconds is shown to result in uniform quasi-periodic structure formation with high repeatability. The subsurface microstructure formed using femtosecond versus picosecond pulses while keeping other processing parameters the same was investigated, providing insight into mound formation processes. Picosecond pulses resulted in finer-grained regions within the mounds, and after a critical pulse count threshold was reached, onion-like layers with alternating high-density copper and highly porous copper oxide regions formed near the surface and blanketed the mounds. Multiple formation mechanisms are proposed to help explain the microstructures that formed using picosecond pulses.

【 授权许可】

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