Additive manufacturing (AM), also known as 3D printing, continues to gain traction in all areas of manufacturing.
It is used to produce everything from fuel nozzles for jet engines to hip implants for geriatric patients and does so quickly and accurately.
Almost any CAD file can be converted into a metal or plastic component with tolerances measured in thousandths of an inch, often with structural integrity rivalling that of conventionally cast and forged materials.
To manufacturers looking for low-cost prototypes, AM is a wish come true.
Why have so many medical and aerospace parts manufacturers and their CNC precision-machining suppliers, cast a wary eye at 3D-printed prototype parts?
This could be due to a lack of confidence that additive manufacturing can provide the precision that is so critical to medical and aerospace parts.
Protomatic is a precision CNC machine shop that specialises in CNC machining for aerospace and medical devices components.
The company embraces additive and subtractive technologies alike, but there are a number of reasons why AM is not readily accepted by the medical and aerospace industries.
The reasons include the possibility of ‘micropores’ that could create infection paths, concerns over material strength in demanding applications and relatively high surface-roughness values compared to machined products.
Despite AM’s 20-year track record, there is still less historical performance data than with subtractive manufacturing methods, which creates some uncertainty or risk in trying this new technology.
Engineers should be knowledgeable about the advantages and disadvantages of both processes, so they can select the best manufacturing method for any given product.
For parts required to stay in the human body for extended periods of time, as well as flight-critical aerospace components, validation testing for tensile and impact strength, temperature performance and hygroscopic behaviour may offset the cost and lead-time benefits offered by 3D printing.
Will this change and AM become more mainstream as it segues into actual production parts? I do not think there is any question that day is coming. For now, companies that depend on life-saving precision continue to depend on subtractive manufacturing.