The contact mode high-speed atomic force microscope (AFM) operates orders of magnitude faster than conventional AFMs. It is capable of capturing multiple frames per second with nanometre-scale lateral resolution and subatomic height resolution.This advancement in imaging rate allows for microscale analysis across macroscale surfaces, making it suitable for applications across materials science. However, the quality of the surface analysis obtained by high-speed AFM is highly dependent upon the standard of sample preparation and the resultant final surface finish. In this study, different surface preparation techniques that are commonly implemented within metallurgical studies are compared for samples of SAF 2205 duplex stainless steel. It was found that, while acid etching and electrolytic etching were optimal for the low resolution of optical microscopy, these methods were less suited for analysis by high resolution high-speed AFM. Mechanical and colloidal silica polishing was found to be the optimal method explored, as it provided a gentle etch of the surface allowing for high quality topographic maps of the sample surface.
Bibliographical noteFunding Information:
The authors would like to thank Dr. Peter Heard for his assistance in FIB etching, and Dr. Ian Griffiths and Mr. John Nicholson for their advice. Also, Outokumpu Stainless AB for the supply of the SAF 2205 duplex stainless steel samples. The authors would also like to thank the physics workshop and NSQI low noise labs at the University of Bristol. This work was supported by the National Nuclear Laboratory (NNL), the Engineering and Physical Sciences Research Council (EPSRC), and the Royal Academy of Engineering (RAEng).
- Engineering Mathematics Research Group
- Sample preparation
- contact mode high-speed atomic force microscopy
- duplex stainless steel
- acid etching
- electrolytic etching
- focussed ion beam etching