French 3D printing specialist Prodways Group has unveiled a new additive manufacturing process claimed to be ideal for producing large titanium parts for the aerospace industry.

The company claims that its so-called Rapid Additive Forging (RAF) process represents a significant improvement over existing titanium component production methods, which often involve a combination of forging and machining techniques. “Certain titanium parts have manufacturing lead times of more than 12 months and implies significant metal wastes,” said the company.
It claimed that the RAF process – which combines elements of additive and subtractive machining – could enable cost savings of upto to 50 per cent on titanium part production.
The technology uses a robot head to deposit molten metal layer by layer in an atmosphere of inert gas. This part is then finished using traditional subtractive machining technology. According to the firm it is able to complete a large part in just a few hours
Prodways claims that the technique differs from other so-called hybrid processes in that it uses a specially developed metal deposition technology that ensures superior metallurgical properties for the end component. The firm said that first metallurgical tests conducted on different parts revealed an absence of porosity and greater mechanical resistance compared with usual 3D metal printing techniques using laser or electron beam sintering.
The process has been tested on various metals, including titanium, and is currently able to produce parts of more than 70 centimetres in size. Prodways said that it is now developing a version that will print parts of up to 2 metres in the main dimension.
The firm said that the technology has already attracted the interest of a number of leading industrial groups.
” lead times of more than 12 months and implies significant metal wastes,”
I believe I have pointed out before.: many traditional aircraft parts manufacturing processes you start with a large lump of metal and cut bits off until you get the shape you want. We simple textile folk start with very small pieces of fibre and filament and add them together until we get the shape we need. Perhaps these new metal additive processes would benefit from a review of what we get up to?
I am not sure I see the forging element of the process. I remember, some years back, Rolls-Royce were developing a (strictly) additive process using a robot arm with a welding torch (fed with titanium wire); I believe they made some larger part than this “RAF process”. Though this process is strictly additive (unlike powder RP processes that have to remove powder – and, possibly, recycle it) but like many processes machining the surface finish is often required – which may be non-trivial for internal or re-entrant surfaces.
Textiles, or continuous fibre (in composite terms), is better treated as sheet material and would be better as additive laminate process (sheet forming) – but, though I have seen some good examples(eg a laminate textile on aluminium for a pressure chamber) – but those such processes would be scalable to large dimensions there seems little interest in developing them; I expect that they are just not fashionable (or their competition has out-lobbied them)