Thermal reactor with mass spectrometer probe (MS probe)
Falk Steuerungssysteme GmbH hat developed a new type of thermal reactor with a mass spectrometer for studying the gas phase reactions that occur during the heat treatment of metals.
The basic schematic diagram for the reactor is shown in Fig. 1., there is a photograph in Fig. 2. The MS probe, for which Falk Steuerungssysteme GmbH has filed for a patent, provides fundamental new information on the chemical reactions that take place at the surface of the metal involving the process gases added to the reactor. With the aid of the MS probe in-situ measurements of the gas phase surrounding metal samples can be made during heat treatment and forming. The temperature-dependency of the chemical reactions between the sample and the reactive gases can be measured quantitatively providing information on the underlying processes. Along with the activation energies of the related reactions, above all optimum conditions for process control in reactors can be obtained, e.g. for the reduction of surface layers in the areas of a material specified for decarbonisation for the subsequent coating, or the hardening of layers close to the surface by nitriding.
In comparison to surface checks made once the process is complete, process tracking using the MS probe has the advantage that the samples are not exposed to the atmosphere. Checking the samples on completion of the thermal treatment in the reactor requires a large number of tests, however using the MS probe the process can be tracked directly significantly shortening the optimisation process. Appropriate detailed checks on the processes in the reactor for the thermal treatment of metals have already been made and will in future be further completed.