This article details investigations on the characterization of various nanofluids as quenchants for industrial heat treatment. It provides a discussion on the preparation, stability, thermophysical properties, and wetting characteristics of nanofluids. The article explains the mechanism of heat transfer in nanofluids and discusses the effect of the deposition of nanoparticles on the probe surface. The article also presents the microstructure and mechanical properties of steel quenched in nanofluids.

Nanofluids offer a completely different behavior of wetting kinetics and heat-removal characteristics, which are exploited in industrial heat treatment for quenching. This article provides information on the important thermophysical properties of nanofluids, namely, thermal conductivity, viscosity, specific heat, density, and surface tension. It reviews wetting and boiling heat-transfer characteristics of nanofluids as quenchants and highlights the importance of using nanofluids as effective quench media for the hardening process during heat treatment. The article describes the effect of nanoparticle addition on the microstructure, mechanical properties of components, wetting kinetics, and kinematics.