Specialty Chemicals for Chromate Conversion
As an anodize seal it is an economical alternative to chromic acid, nickel acetate, nickel fluoride, and hot water seals.
CHEMEON TCP-HF (Hex Free) Capabilities
|Applications||Chemical conversion coatings. Anodized aluminum sealer. Passivate and anti-tarnish.|
|Industry Specifications and Standards||MIL-DTL-81706. MIL-DTL-5541 Type II. MIL-C-5541 Class 1A and Class 3. ROHS. REACH. WEEE. ELV. OSHA, ASTM B921. QPL.|
|Substrates||Bare aluminum and anodized aluminum. Zinc and zinc alloys. Magnesium. Galvanized steel. IVD. Cadmium. Silver. Brass. Titanium. Stainless Steel. Iron alloys. Zirconium.|
|Properties||Extended corrosion resistance. Paint adhesion. Electrical properties. Coating durability.|
|Application Methods||Immersion. Spray.|
|Corrosion Resistance||336h NSS bare aluminum. 3,000h+ anodized aluminum.|
|Temperature Exposure||Can be dried at 250°F Can be baked for hydrogen relief at 250°F for 24+h without loss of performance|
|Product Advantages||Lower solution operating temperature. Harder than conventional hexavalent. Can be applied and dried in bulk. No topcoat required. Extreme temperature exposure - UP TO 450°F. Average coating weight 22.88 mg/ft2.|
|Industries Served||Aerospace. Military/Defense. Automotive. Medical. Cookware. Commercial. Architectural. Marine. Avionics. Electronics. Heavy equipment.|
Related products include:
- developed for enhanced performance for 2000 and 7000 series alloys,
- offers better corrosion resistance with etch,
- designed for consistent results and better coating weight,
- allows more flexible pre-treatment process parameters.
It is optimized for spray applications and effective as a pre-paint/powder coat anti-corrosive chemical.
CHEMEON TCP-HF (Hex Free) Spray Bottle*
Small touch-up spray use.
Touch-up and field repair use.
- Hexavalent chrome is a known carcinogen and highly regulated. TCP-HF contains a small amount of trivalent chrome which is not a carcinogen and is non-toxic.
- Disposal of hexavalent chrome is more expensive. Hexavalent chrome must be reduced to a trivalent state where the converted trivalent chrome content is precipitated and removed as a non-toxic substance. The wastewater is pH adjusted and sent to drain. Hexavalent chromate baths require frequent dumps which puts more demand on the treatment system. Chemicals, manpower and compliance issues are costly.TCP-HF, however, uses chrome in its non-toxic trivalent state. The amount of trivalent chrome in the TCP-HF bath is minimal and the rinse waters generate only trace amounts of trivalent chrome in the waste stream. The rinse water in most cases only requires pH adjustment for discharge to the drain. A TCP-HF bath is very rarely dumped. The Navy has operated TCP-HF process baths for over 2 years without dumping and remaking. TCP-HF solution is simply added back to the tank to account for drag-out and evaporation losses.
- Hexavalent chromate systems must be heated. TCP-HF is applied at room temperature and does not require heating. This saves in energy costs and production down-time during bath start-up.
- Hexavalent chromates must be ventilated and the air must be discharged within applicable environmental limits. TCP-HF is odorless and does not require ventilation. Again, energy, manpower and compliance savings are realized.
- TCP-HF is a drop in replacement for hexavalent chromates. Pre-treatment chemistries and application method (Immersion, spray, wipe) will remain the same. This eliminates the need for additional equipment or system retrofits.
- TCP-HF is less acidic than hexavalent chromates. Etching of the part is minimized while the part dimensions are maintained.
- TCP-HF withstands temperatures that meet MIL-DTL 81706B 250°F allowing for greater process flexibility. Hexavalent chromates do not perform as well when subjected to elevated temperatures.
- TCP-HF has performed as well or better than hexavalent chromates in a variety of applications and tests. The Navy tested the product on entire airframes for the F/A18 as well as S3 tail sections. The planes were flown for an extended period with excellent long-term results. It has also been tested and approved for the exterior framework of the United States Army Amphibious assault vehicle being manufactured by General Dynamics at GDDS Virginia. Of twenty products tested TCP outperformed all by nearly twice the neutral salt spray corrosion testing.
* In 2013, CHEMEON Surface Technology, formerly Metalast Surface Technology, acquired all assets of Metalast International, LLC, and is the sole source of products and services known and marketed as Metalast prior to June 10, 2015, now marketed under the CHEMEON mark. CHEMEON is not affiliated with David M. Semas. Read more about the CHEMEON name change here.