The new process overcomes a key challenge in the use of titanium for certain applications. Despite its high strength and light weight, titanium’s poor resistance to abrasive or adhesive wear makes it unsuitable for use as, for example, aircraft landing gears and automotive internal combustion engines.
This can be overcome by plating the titanium, which enhances its performance characteristics, including improved lubricity, corrosion resistance and conductivity, as well as heat reflection and emissivity. Unfortunately, titanium is notoriously difficult to plate, largely because of an oxide film which forms the moment it becomes exposed to oxygen.
Existing plating techniques to overcome this challenge have proven to be highly corrosive, potentially poisonous or short-lived in their effectiveness. SIFCO ASC undertook extensive experiments with TI 6-Al 4-V and TI 6-6-2, two of the world’s most widely used titanium alloys, to perfect a more efficient plating process.
The result is a plating process which includes surface pre-treatments of mechanical finishing, followed by an etch, activation, and finally the introduction of a thin layer of nickel. This pioneering approach brings all the benefits of selective plating – including versatility and convenience – together with enhanced safety and component quality.
The biggest challenge for SIFCO ASC was to avoid oxidisation – and therefore costly scrappage of compromised titanium – the electrolyte solution must flow continuously over the component at all times. But, this problem could be eliminated through automation.
“Titanium offers almost unlimited potential to drive improvements in the reliability and performance of mission-critical components,” explains Derek Kilgore, engineering manager at SIFCO ASC. “Yet while this benefit is within reach, it has also proved challenging to grasp – largely because of the complications surrounding the plating process.
“These challenges can be essentially removed through investment in automated systems. Combining the ease and convenience of selective plating, they not only reduce human error, but also introduce vital benefits in terms of quality, repeatability and traceability or data logging, as well as productivity and user safety.”
The use of automation also makes the process more repeatable, an advantage for mission critical applications where absolute and consistent quality is demanded. It is also fully traceable, making it easy to identify specific components should there ever be the need to investigate or recall specific products.
SIFCO ASC can offer titanium plating as a contract service either on-site at a customer’s premises or at a job shop.
The automated system designed by SIFCO ASC uses a portable TechnoPlate - a programmable power pack which not only allows repairs to be plated in situ, but also stores the volts, amperage and amphere hours, eliminating the risk of human error and oxidisation.
Additionally, for non-titanium applications, SIFCO ASC can design, specify, deliver, and commission simple workbenches or fully automated workstations with robotic systems to handle components, anodes and solutions through RFID and barcode tagging. The only human intervention necessary is programming and replenishing solutions.