US Patent 7589161 - Nanoparticle composition for quenching steel

http://www.freepatentsonline.com/7589161.html

The hardening of steel requires a step of rapid cooling performed by a variety of liquid solutions such as water-based or oil-based compositions. Water solutions are easy to dispose of and inexpensive but can result in too rapid cooling which leads to strained microstructures in the steel. Oil-based solutions provide slower cooling but are more expensive and can be dangerous. This patent from the Industrial Technology Research Institute teaches an alternative based on inorganic nanoparticles providing for an optimization of the desired qualities for steel quenching. Claim 1 reads:

1. A polymeric quenchant, comprising:

an inorganic nanoparticle,

a water-soluble polymer, and

water,

wherein a weight ratio of the inorganic nanoparticle, water-soluble polymer and water is about 0.05-5:1-5:100, and the inorganic nanoparticle is talc, smectite clay, vermiculite, halloysite, sericite, saponite, montmorillonite, beidellite, nontronite, mica, hectorite, or a combination thereof.