Aluminum Oxide Conversion Coating Alternative to Cold Blackeners

Birchwood Tecnologies’ Microlok AO process forms a non-toxic aluminum oxide conversion coating that is 1.5 microns (0.000060") thick and designed to be tightly adherent to the metal surface. When sealed with a rust preventive, the silver/black finish provides improved corrosion protection over cold blackening without pollution hazards, the company says. The process also provides anti-galling protection to aid in assembly and startup, temperature stability ranging to 1,400°F, and safe operation from 120 to 140°F with no boiling or splattering. According to the company, the solution contains no regulated chemicals and process rinse waters are generally sewerable as non-hazardous discharge.