SY-322 Chromium-Free Aluminum Alloy Passivator

SY-322 aluminum alloy chromium‑free passivator is a colorless liquid that contains no lead, cadmium, (trivalent and hexavalent) chromium, mercury, or PBB/PBDF. It is an environmentally friendly passivator for treating surface films on aluminum and aluminum alloys. The resulting film can serve as a final finish or as a primer for subsequent paint coating, powder coating, or application of higher‑performance topcoats, and it can also act as a base for surface‑bonding adhesives. Its corrosion‑resistance performance is comparable to that of hexavalent chromium passivation; on cast aluminum alloy surfaces, it even exceeds the corrosion‑resistance standards specified in MIL‑DTL‑81706 and MIL‑DTL‑5541 (based on ASTM B‑117 and DIN EN ISO 9227 neutral salt spray test criteria, with initial white rust appearing only after more than 336 hours).

SY-321 Aluminum Alloy Trivalent Chromium Passivation Agent

SY-321 trivalent chromium passivator for aluminum alloys is a clear green liquid based on trivalent chromium, with a density of 1.005 g/mL (range: 1.00–1.01 g/mL) and a pH close to 3.4. It serves as a post‑treatment solution for anodic oxide coatings on aluminum and aluminum alloys, and can also be used as a pretreatment step prior to painting, powder coating, or adhesive bonding. It forms a transparent, lightly colored, highly heat‑resistant inorganic passivation film whose corrosion‑protection performance surpasses that of hexavalent chromium passivation processes, even exceeding the corrosion‑resistance standards specified in MIL‑DTL‑81706 and MIL‑DTL‑5541 (as determined by neutral salt spray tests according to ASTM B‑117 and DIN EN ISO 9227, with initial white rust appearing only after more than 336 hours).

SY-320 Aluminum Alloy Chromating Agent

SY-320 aluminum alloy chromating agent is an orange or brown powder used as a primer for aluminum and aluminum alloy surfaces or to form a standalone coating. The resulting film exhibits a golden‑yellow color, with a thickness of approximately 5–10 μm, and offers excellent corrosion resistance and decorative appeal. In the bare‑metal condition, it withstands neutral salt spray testing for more than 96 hours. It also provides outstanding resistance to discoloration, and its chemically converted coating adheres strongly, significantly enhancing the bond between the substrate and subsequent coatings or paints. The process can be carried out at ambient or low temperatures, with simple operation and management; bath formulation and monitoring are straightforward, performance is stable, service life is long, and production efficiency is high, resulting in low overall costs.