Titanium-plated polymers could revolutionise composite parts
Modern manufacturing benefits from a wide range of cost-effective lightweight composite parts, such as the metal-plated polymers often used (but with poor adhesion) for decoration, including for bath fittings. Another common use is for electronics – such as for enclosure boxes – as the metal plating offers conductivity, while the polymer ensures light weight. But a problem with traditional metal plating is that most metals are not biocompatible, making them unsafe for human touch. Due to its biocompatibility, nickel-chromium plating has traditionally been used as a workaround for some applications, but its processing requires hazardous chemicals. Developing an innovative chemical treatment for polymer surfaces, coupled with a specialised engineering plating process, Polymertal has enabled the production of complex hybrid metal-polymer components. Through the EU-funded TiPlate project, the company has developed titanium plating using only safe REACH- and ROHS-compliant chemicals. “We believe that TiPlate could revolutionise the metal plating industry where biocompatibility is crucial, for example for medical equipment or car parts which come into contact with the human body,” says Sabina Ifraimov, TiPlate technological and scientific manager. With work to secure a patent well-advanced, along with targeted commercialisation efforts, applications within various industries are currently being explored.
Electrophoretic deposition optimises the titanium plating process
Traditional titanium metal plating is achieved using either vacuum evaporation technology or electrolytic plating from molten salts. Both have limitations. Evaporation technology creates a very thin layer of metal plating (up to 1 micron) with some areas on complex parts at risk of being shielded from the plating process, ultimately compromising plating uniformity. Additionally, the size of the structures able to be plated is limited. As the high temperatures (over 800 degrees Celsius) necessary for electrolytic plating from molten salts would decompose polymers, the team tried electroplating based on dissolving titanium salt in an electrolyte solution, then applying an electrical current to convert it to metal. This also proved ineffective. “Traditional aqua-based solutions lead to problems such as hydrogen overvoltage, with energy wasted converting the water’s hydrogen into gas, making the process highly inefficient. Further exacerbated by the formation of hydrogen bubbles, resulting in porous plating,” explains Ifraimov. The breakthrough was developing a novel plating process based on electrophoretic deposition from dispersed titanium particles, at room temperature. The team trialled different plating parameters, including tweaks to the dispersion composition and cell configuration to optimise the process. Multiple evaluation techniques were then deployed, including: electrochemical measurements, such as cyclic voltammetry, alongside morphological assessments using light microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy.
Disrupting the metal-polymer components market
The result is a cost-effective process which Ifraimov believes could open up diverse market opportunities. “TiPlate offers multiple advantages: reducing the amount of titanium needed which keeps costs down and increasing production efficiency, while the lightweight components produced will reduce transportation costs, still offering high strength and heat resistance,” adds Ifraimov. As various industries seek to benefit from these competitive advantages, Ifraimov believes that the results will likely lead to new job opportunities in manufacturing, research and development, and sales, while supporting broader EU efforts for next-generation materials, such as the project GLACERCO. Polymertal is now focusing on the European market and is currently working to set up a production site, after securing advance sales through participation in exhibitions, such as Automechanika and Formnext. “Currently, we are strategically positioned in key automotive, semiconductor and medical industries, with notable collaborations and partnerships with industry leaders such as Porsche, BMW, Continental, ASML and Johnson & Johnson,” concludes Ifraimov.
Keywords
TiPlate, composite, component, metal, polymer, titanium, plating
