Socomore TCS/PACS

Apticote 300TP is based on Socomore TCS/PACS chemistry and does not use chromates. The process solution is safer to use than Alocrom and does not contain materials currently defined as SVHC’s in either EU or UK REACH legislation. This also means they are unlikely to be under threat from chemical legislation in the medium to long term.

The TCS solution produces the conversion coat and, like other chromate free conversion coat processes such as Surtec 650V, is a mixture of non-hazardous trivalent chrome and zirconium. The coating produced from this solution contains very small microcracks giving poor corrosion performance on high copper alloys. The PACS solution contains lanthanum and hydrogen peroxide which seals the cracks in the conversion coat.

Corrosion resistance of anodising or conversion coatings on aluminium will be heavily dependent on the substrate alloy and its surface condition. High copper/zinc alloys or cast materials will have significantly reduced corrosion resistance compared to 1000, 5000 or 6000 series wrought alloys.

A typical production Class 1A Alocrom 1200 coating on 2024 alloy will last 350-500hrs until the first sign of corrosion when tested in accordance with ASTM B117. Apticote 300TP has shown to provide similar levels of corrosion resistance on 2024 alloys. On one occasions we have achieved over 1000 hrs before the first corrosion spot with Apticote 300TP.

With sulphuric acid anodising, any seal will pass the Quality Control 500hr salt spray test. To differentiate the 3 typical seals requires far longer testing. With a 12-18µm thick coating on 2024 alloy, the following can be expected:

A 12-18µm thick coating of Apticote 300STP (A sulphuric anodised base layer sealed with Apticote 300TP) will match the corrosion performance of nickel acetate sealing.Apticote 300TP will meet the electrical conductivity requirements of MIL-DTL-81706 for MIL-DTL-5541 Class 3 coatings on aluminium alloys.Paint adhesion (chromate and non-chromate) on both Apticote 300TP and ApticoteSTP is very good.

Hot water seal	1000hrs
Nickel acetate seal	1700hrs
Sodium dichromate seal	2500hrs

A 12-18µm thick coating of Apticote 300STP (A sulphuric anodised base layer sealed with Apticote 300TP) will match the corrosion performance of nickel acetate sealing.

Apticote 300TP will meet the electrical conductivity requirements of MIL-DTL-81706 for MIL-DTL-5541 Class 3 coatings on aluminium alloys.

Paint adhesion (chromate and non-chromate) on both Apticote 300TP and ApticoteSTP is very good.