5-8 September 2022
Wyndham Grand Salzburg Conference Center
Europe/Vienna timezone

Control of quench severity by applying an electric potential during heat treatment of aluminium alloys

7 Sep 2022, 15:10
25m
Room 3

Room 3

Oral Presentation Quenching technology (equipment and quenchants) HEAT TREATMENT

Speaker

Peter KRUG (Cologne University of Applied Sciences)

Description

Since quenching in cold water usually leads to distortions of the quenched component, it is obvious to either increase the temperature of the quenching bath (if necessary to near boiling point) or to use a different quenching medium, e.g. polymer solutions and gaseous media, respectively. In all cases, this is usually associated with higher investments and/or operating costs.

It would be more elegant, however, to achieve this with one and the same medium. This could be done by applying an electric field between the component to be quenched and a counter-electrode, which is immersed in the quenching medium. The latter must be a salt solution, an acid or lye, as the quenching medium must have at least a certain electrical conductivity. As already reported at the ECHT/QDE Conference 2021, the arrangement described above was able to stabilize the film boiling period for several additional seconds before nucleate boiling and rewetting of the component took place. This process can be controlled within certain limits by selecting the current density or the duration of the current flow. The component was connected as a cathode. Reversing the polarity, however, did not lead to a change in the quenching process.

In this paper, the influence of further variations of current density and electric potential, as well as the importance of an optimized design of the counter-electrode in terms of geometry and material, and the influence of the surface structure of the component to be quenched are to be demonstrated. If one interprets the arrangement casually as a capacitor or as a series of capacitors connected in series, a vivid explanation of the observed phenomenon emerges. This model can be used for further, targeted optimizations.

Speaker Country Germany
Register for the Tom Bell Young Author Award (TBYAA)? No

Primary author

Peter KRUG (Cologne University of Applied Sciences)

Co-authors

Mr Thomas TENOSTENDARP (Cologne University of Applied Sciences) Mr Waldemar STIPS (Cologne University of Applied Sciences)

Presentation Materials

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