The quenching curves (temperature vs time) for small (similar to 1 cm) metallic spheres exposed to pure water and water-based nanofluids with alumina, silica and diamond nanoparticles at low concentrations (<= 0.1 vol%) were acquired experimentally. Both saturated (Delta T(sub) = 0 degrees C) and highly subcooled (Delta T(sub) = 70 degrees C) conditions were explored. The spheres were made of stainless steel and zircaloy, and were quenched from an initial temperature of similar to 1000 degrees C. The results show that the quenching behavior in nanofluids is nearly identical to that in pure water. However, it was found that some nanoparticles accumulate on the sphere surface, which results in destabilization of the vapor film in subsequent tests with the same sphere, thus greatly accelerating the quenching process. The entire boiling curves were obtained from the quenching curves using the inverse heat transfer method, and revealed that alumina and silica nanoparticle deposition on the surface increases the critical heat flux and minimum heat flux temperature, while diamond nanoparticle deposition has a minimal effect on the boiling curve. The possible mechanisms by which the nanoparticles affect the quenching process were analyzed. It appears that surface roughness increase and wettability enhancement due to nanoparticle deposition may be responsible for the premature disruption of film boiling and the acceleration of quenching. The basic results were also confirmed by quench tests with rodlets. (c) 2009 Elsevier Ltd. All rights