Phoskro A-100 from Puma Chemical is a liquid multi-metal phosphate system for treating steel and aluminum. It contains iron for durability, manganese for hardness, zinc for galvanic protection and molybdenum for passivation. It can be used in automated feeding systems and operates effectively at low temperatures, making it suited for use with a low-temperature cleaner in a single stage, if soil conditions permit.
During the coating process, the system first forms a ferro-molybdate complex, then zinc and iron pyrophosphates are deposited on top. According to the company, the molybdate complex is very tight in nature and acts like a plated coating, preventing penetration to the bare metal even with severe usage. Overall, Phoskro A-100 is formulated to produce a denser and tighter crystal structure than iron phosphate systems, resulting in increased adhesion and durability of paint finishes. The paint/coating bond it produces offers corrosion resistance comparable to those offered by many zinc phosphating systems, Puma says. The coating deposited is a continuous overlay without any “holidays” or bare spots, or unreacted chemicals.
The Phoskro A-100 system is designed to be easy to use and control, requiring no separate pH-controlling additive. It can be used in spray or immersion applications of one or more stages, includes no detergent, offers minimum sludge and scale formation, and is low foaming. Even at solution temperatures of 100°F or lower, the system provides coating weight of 270 mg/m², which meets requirements of Federal Specification TT-C-490B Type II, the company says.