Environmentally friendly anodising

At its dedicated £1m in-house electro-plating facility, Weymouth based metal finishing specialist, Tecan has developed an environmentally friendly process for the anodising of titanium parts - a process believed to be unique in the UK.

Titanium offers excellent corrosion resistance, it is resistant to dilute sulphuric and hydrochloric acid, most organic acids, most chlorine gas, and chloride solutions - which means penetrating its surface oxide layer in preparation for anodising is a particularly tough job. The ability to successfully anodise titanium is in itself uncommon, but to do this without using aggressive surface preparation acids is particularly unusual.

Tecan has achieved this without resorting to standard preparation solutions which contain non-dilute hydrofluoric and sulphuric acids. Instead, the company has developed a proprietary method based on alkaline solutions which successfully pre-etches titanium parts prior to anodising, while effectively protecting both its staff and the environment.

Crucially, the new method meets the established ISO 8080 standard without the use of acids. The company has also developed equally 'green' techniques for plating titanium, with finishes such as PTFE and nickel, to facilitate novel assembly requirements or for aesthetic finishes.

Typical application areas include low-volume high-specification parts for new-generation military, aerospace and harsh industrial environments.

Titanium anodising is often used a pre-painting process to provide a good 'key' for high-performance paint finishes. The process is flexible enough to create varying levels of anodising to meet individual needs. A well-established distribution service can, subject to qualification, despatch finished parts within three working days of order.

The £1m purpose-built facility provides OEMs and specialists with access to surface-finishing and cost-effective bespoke plating for both everyday solutions and the most demanding niche applications.

Finishes available include acid gold, pure gold, silver, bright tin, 60/40 tin lead, 90/10 tin lead, sulphamate nickel, electroless nickel, copper, Type 1 sulphuric anodising and Type 3 hard anodising (colours to specification), stainless steel passivating, and Alochrome 1200 chemical blackening.

Non-destructive XRF and atomic absorption test instruments are employed, to ensure consistently flat and even surfaces and desired thickness meet the required specifications. QA programmes can be tailored to suit individual statistical process control (SPC) needs, with traceability reports generated as necessary.