Microstructure Preparation Using Glow Discharge Plasma Taking the Examples of Ni-Ti, Cu-Zn and a Ni-Based Alloy

Abstract

The present work investigates the universal applicability of glow discharge plasmas for the microstructure representation of different materials taking the example of Ni-Ti alloys, Cu-Zn alloys, and the Ni based alloy “Hastelloy C 276”. Results are compared with the results provided by classical etching methods. Microstructures became visible for the previously mechanically polished materials within a few seconds, even without detailed optimization of the excitation conditions of the glow discharge plasma. The results partially significantly outperfomed the results of the classical preparation techniques with respect to the detectability of structural details such as grain and phase boundaries. Due to the demonstrated wide and relatively uncomplicated applicability, the per se established glow discharge technology is expected to have a huge potential for application for a rapid and high-contrast microstructure representation.

Occurrence and Morphology of Martensite in β-Cu-Zn Alloys with Minor Al Additions

“…The polished samples were analyzed directly or subjected to two different etching processes for increasing the phase contrast. Either glow discharge (GD) plasma etching (600 V AC, 2 hPa, Argon 99.999 pct, anode diameter: 2.5 mm, duration: 5 seconds [19] ) or a two-step chemical etching consisting of 6 seconds swirling in 10 wt pct NaOH solution and subsequent 5 seconds swirling in a solution of 120 mL distilled Water and 10 g ammonium tetrachlorocuprate(II) dihydrate were carried out. Optical microscopy with and without polarized light that allows the identification of martensite based on its birefringent properties.…”