Laser powered heating stage in a scanning electron microscope for microstructural investigations at elevated temperatures

Abstract

A laser powered heating stage designed for application in high vacuum environment of a scanning electron microscope (SEM) is presented. It was developed to observe and characterize microstructural changes in crystalline materials at elevated temperatures up to 1000 degrees C. The approach utilizes the power output of a commercial infrared diode laser in order to heat up specimens without interference with the electronic system of the SEM. The heating stage can be used in combination with any standard characterization technique applicable for SEMs--electron backscatter diffraction, orientation contrast imaging, x-ray energy dispersive spectrometry, etc. The results of test measurements are presented.

Nucleation and variant selection during the α–γ–α phase transformation in microalloyed steel

“…For this purpose, a laser-powered heating stage was developed at the Institute of Physical Metallurgy and Metal Physics of RWTH Aachen University. Details of its setup and operation are given elsewhere [14]. The basic features are summarized below.…”

EBSD coupled to SEM in situ annealing for assessing recrystallization and grain growth mechanisms in pure tantalum

“…Most of the in situ furnaces consist of a heated floor on which the sample is laid down. Thermal exchanges are done by conduction to heat the sample (Piazolo et al, 2004;Kirch et al, 2008;Borthwick & Piazolo, 2010). Depending on the heating device, samples may have different sizes.…”

“…Another asset of our device is the maximal reachable temperature (1200 • C). The classical temperature range for the different studies using other types of heating stages is between 200 • C and 600 • C. Few works were done around 900 • C Kirch et al, 2008). To our knowledge, only one study was done at a higher temperature of 1250 • C but the stage was not integrated in an SEM chamber (Yogo et al, 2010).…”

Migration of specific planar grain boundaries in bicrystals: application of magnetic fields and mechanical stresses

“…Alternatively, migration and shape of the grain boundaries in any crystalline material can be measured using the orientation contrast revealed by backscattered electrons in a scanning electron microscope (SEM), since the intensity of backscattered electrons is very sensitive to orientation. For instance, with a specially designed laser powered heating stage in situ measurements of curvature driven grain boundary motion can be conducted at temperatures up to 1000°C [17].…”