Cryogenic quenching process enhancement through coating and microstructure optimization

In this work, we explore the impact of coatings and microstructures on heat transfer during a cryogenic quenching process. An easily reproducible quenching test is presented as a benchmark for testing different solutions. The study involves two different flat polymeric coatings as well as three porous microstructures. The results show that pairing a low-conductive coating with an appropriate porous surface microstructure on top of a stainless-steel plate can reduce the chill down time, accelerating the transition from room temperature to liquid nitrogen temperature, by a factor of five. High speed video recordings have been used to analyse the quenching process with different coatings and microstructures showing how the suppression of the film boiling regime is the key to enhancing the quenching process.