Potassium hexacyanoferrate 3

During this work, laboratory grade ultrapure
Milli-Q water (conductivity <0.1 μS/cm) was used to prepare
all solutions, unless otherwise specified. Sodium tetraborate decahydrate
(Na₂B₄O₇·10H₂O),
potassium chloride (KCl), chroroplatinic acid hexahydrate (H₂PtCl₆·6H₂O), sulfuric acid (H₂SO₄), and 30 wt % hydrogen peroxide solution were purchased
from Sigma. Potassium hexacyanoferrate(III) (K₃[Fe(CN)₆]) and potassium hexacyanoferrate(II) trihydrate (K₄(Fe(CN)₆)·3H₂O) were purchased from Roth.
All reagents were used as received, without further purification.
Whatman chromatography paper grade 1 (Whatman International Ltd.,
Floram Park, NJ, USA) was used for laser irradiation and LIG formation.
As transfer substrate models, Leukoplast Fixomull medical grade polyurethane
tape, Hypafix polyester wound dressing tape, polydimethylsiloxane,
and 3M Transpore polyester fixing tape were used.

For the evaluation of the microstructure after heat treatment, a metallographic cross-section was taken from the specimens. Cutting was performed using a wire-erosion technique (Matra Fanuc Robocut, Neuhausen, Germany) in order to avoid heat effect. The microstructure was etched with Nital (3% alcoholic HNO_3, Carl Roth, Karlsruhe, Germany) as standard and documented with the light microscope (Leica, Wetzlar, Germany) as well as the scanning electron microscope (Tescan, Brno, Czech Republic). For the visualization of the carbide distribution after quenching and tempering, the microsection was etched according to Murakami (10 g Potassium hexacyanoferrate (III)/10 g NaOH/100 mL H₂O, all reagents from Carl Roth, Karlsruhe, Germany) for 5 min at 50 °C. Vickers hardness testing was also performed on the cross-section. The core hardness was determined five times, and the average value and standard deviation were formed from the results.