Examination of hybrid manufacturing techniques to produce titanium parts for safety-critical applications in aerospace

Project aim

To determine the effectiveness of laser metal deposition and wire and arc additive manufacturing to deposit an aerospace high strength beta-titanium alloy on a forged substrate material, with a particular interest in the microstructure, residual stress, and mechanical properties around the substrate and deposition interface.

Project background

Titanium alloys are increasingly being used in heavily loaded applications such as aircraft undercarriages due to their low density, excellent corrosion resistance, and good fracture properties. The downside of using such alloys is that they are expensive to produce. Typical manufacturing methods are ‘subtractive’: machining material from large forgings. The process produces high material waste. Moreover, Titanium is notoriously difficult to machine. Therefore, closer to form manufacturing options, such as Additive Manufacturing, are of interest to industry.

This project aims to investigate the use of additive manufacturing technologies, such as laser metal deposition and wire and arc additive manufacturing, to add details to safety-critical titanium forgings. Such a process results in microstructural, and therefore mechanical property, variations between the parent part and the additive section. Such structures also demonstrate high levels of anisotropy and residual stress which must be carefully managed.