A novel laboratory set-up for investigating surface and interface reactions during short term annealing cycles at high temperatures

Abstract

High temperature oxidation is an important research discipline that covers many topics in steel manufacture and modern energy research. To account for the need of adjusting accurate processing conditions, recent developments of the high temperature laboratory setup at the Max-Planck-Institut für Eisenforschung GmbH will be presented. The experimental assembly has been optimized to investigate surface and interface reactions at elevated temperatures in low oxygen activity gases, covering a large field of experimental possibilities. Many efforts have been taken to enable an accurate control and in situ monitoring of process conditions such as gas flow, gas composition, impurity content, and mass change of the sample.

Theoretical and experimental analysis of selective oxide and nitride formation in Fe–Al alloys

“…Four iron-aluminum alloys were used in this study, ranging from 1 wt.% to 8 wt.% Al (compositions listed in Table 1) were cut to 15 mm  15 mm  2 mm pieces and a small hole with a diameter of 1.5 mm was drilled in each sample to hang it from an alumina rod in a sample holder in the gas-tight alumina tube of a horizontal tube furnace [17]. They were then ground on silicon carbide grinding papers through 1200 grit and then the surfaces were cleaned using deionized water and ethanol to remove any residual oils or other impurities before heat treatment.…”

Modelling and experiment of selective oxidation and nitridation of binary model alloys at 700 °C – The systems Fe, 1 wt.%{Al, Cr, Mn, Si}

“…Great care has been taken to reduce the content of oxygen impurities below a limit of 5 ppm O 2 . All process parameters during heat exposure were recorded automatically by using the laboratory equipment as described in [35]. After thermal treatment, the sample surface was analysed by standard optical microscopy.…”

Effect of surface roughness on optical heating of metals

“…A surface roughness above 0.20 µm possesses a remarkable increase in optical absorption (increasing at 1.5 µm by almost a factor of 3) leading to a higher efficiency for optical heating. However, the measured thickness of the roughness zone of these samples becomes larger than 1 µm (see Figure 1), which is often too much to exclude geometrical effects on the results of otherwise welldefined thermal exposures [13,14,46].…”

“…While the reflectivity R for a specularly reflected beam is essentially depending on the material of the substrate, light scattering S strongly depends on surface properties, like roughness [8]- [12]. Despite the fact that optical heating is used in many modern hightemperature laboratories [13,14], only little is known about the effects of surface preparation on efficiency of optical heating. Up to now, surface preparation is often chosen on an intuitive base.…”