Top 7 things to know about additive manufacturing: where it fits in aerospace production
Additive manufacturing (AM), often called industrial 3D printing, builds a part by depositing material layer by layer until the geometry is complete. It works in the opposite direction to subtractive CNC machining, which starts with a solid block and removes everything that isn’t the part. That difference matters, because it changes what is cheap, what is hard, and what fails.
In our engineering work, AM earns its place in three situations. The first is rapid prototyping, where a design needs to be checked in physical form within days rather than weeks. The second is geometry that a cutting tool simply cannot reach, such as internal cooling channels or lattice structures. The third is low-volume production where tooling would never pay back. Outside those cases, CNC or casting usually remains the better route.
We always start a project by defining the problem before picking a process. Ask what mechanical properties the part must carry, what dimensional tolerance is required, and how many pieces are needed over the product life. Those three answers will eliminate most of the options before any machine is booked.
1. The main AM processes and how material choice drives the decision
Each AM technology grew up around a different material family, and the process you choose will narrow your material options immediately. Fused deposition modelling extrudes thermoplastic and is inexpensive and easy to run, but the surface finish is coarse and the layer lines are visible. Stereolithography cures liquid photopolymer with a UV source and delivers smoother surfaces and finer features, though the resins tend to be brittle.
Selective laser sintering fuses polymer powder and needs no support structures, which gives real design freedom for functional nylon parts. For metal, direct metal laser sintering and selective laser melting use a laser to fuse metal powder, and this is the route to load-bearing metal components. Titanium alloys such as Ti-6Al-4V are the most common example in aerospace brackets and housings.
When you compare options, look beyond unit price. Build volume limits the maximum part size, layer thickness drives surface roughness, and post-processing can double the lead time. A cheap quote for a process that cannot hold your tolerance is not a saving.
2. Design for additive, not a copy of the machined drawing
The most frequent problem we see is a drawing that was designed for milling and then sent to a printer. The part prints, but it arrives with warpage, trapped support material, or channels that closed up. AM has its own rules, and they differ from machining rules.
Overhangs steeper than the process allows need support or a redesigned angle. Thin walls can distort as the thermal gradient pulls the layers. Small holes and slots may fill with partially sintered powder or resin. Our habit is to orient the part so critical faces print in the least demanding direction, and to add support only where the part truly needs it. Expect at least one design iteration; the first print almost always teaches you something.
3. Anisotropy means printed strength is not wrought strength
A common mistake is to take handbook data for forged or cast material and apply it directly to a printed part. Printed parts behave differently. The most important difference is anisotropy: strength measured along the build direction can be noticeably lower than strength across the layers. Heat treatment after printing changes the internal microstructure again, sometimes for the better and sometimes not.
For any load-bearing component, request material property data from the supplier for their specific process and post-treatment, or run witness coupons built in the same job. Generic numbers rarely reflect your actual production route, and a structural decision made on them can be expensive to reverse later.
4. The cost crossover arrives sooner than most people expect
Cost is the question we hear most often. Additive is economical at low quantities because it avoids the fixtures and dies that conventional routes demand. As volume climbs, the per-part cost of machining or casting usually falls below AM. In our quoting practice we tend to frame it in three bands: a handful of units for testing, a few dozen for a pilot run, and beyond a few hundred units a careful side-by-side comparison is essential.
Product developers, prototype shops, and single-unit replacement parts gain the most. Watch the hidden costs: metal powder is expensive, and the removal of supports and stress-relief heat treatment add labour and time. Always base the decision on a written quotation for your own geometry rather than on rule-of-thumb estimates.
5. Verifying quality with non-destructive inspection
Printed parts can carry defects that are invisible from the outside. Gas porosity trapped inside the material, cracking from thermal stress, dimensional drift from distortion, and loose powder left in internal cavities are all typical. A part can look flawless and still fail under cyclic load.
The methods we rely on include coordinate measurement to confirm dimensions, computed tomography to map internal porosity and detect hidden voids, and mechanical testing of witness coupons printed alongside the batch. Inspection adds cost, so scale it to the criticality of the application: a decorative fixture does not need the same scrutiny as a bracket carrying flight loads.
6. Industrial and aerospace applications in Vietnam
In Vietnamese manufacturing, AM is most often used for moulds, jigs, check fixtures, and prototype components. A jig printed in polymer, for example, can cut the wait compared with traditional machining, which matters when production lines change design frequently.
Aerospace work is a different world. Components flying on aircraft require certified process control, traceable material lots, and complete build records. Without that documentation, a beautifully made part may still be rejected, so the paperwork must be planned from the first design review.
7. Choosing a supplier with real capability
When evaluating a supplier, check the range of technologies, the quality certifications they hold, and their post-processing capacity, including cleaning, heat treatment, and finishing machining. Lead time and responsiveness to design feedback also reveal a great deal about how the shop actually runs.
Ask direct questions. What are the measured mechanical properties for the material and process you will use? How is each batch inspected? Will they recommend design changes for AM, or simply print what you send? For projects that combine printing with precision machining, it is worth reviewing a provider of precision mechanical machining services so that tight tolerances and the required surface finish can be delivered on the same job.
To help with related reading, our guides on additive manufacturing for aerospace prototyping, designing flight-ready titanium parts via 3D printing, and common mistakes with titanium alloys go deeper into the material and design details behind these points.
Frequently asked questions
Can metal additive parts carry structural loads?
Yes, provided the material data and the process are qualified for that specific application. Generic handbook values should never be the sole basis for a load-bearing decision.
What drives the cost of an industrial 3D printing project?
The main drivers are the process, the material, part size and orientation, and the amount of post-processing. Sending a drawing with the required tolerances and finish gives the most accurate quotation.
Does moving a part to AM require redesign?
Usually, yes. Geometry optimised for milling is rarely optimal for printing, and adjusting overhangs, wall thickness, and support strategy typically improves the result.
How long does industrial 3D printing take?
Lead time ranges from a few days to several weeks depending on size, quantity, and technology. Metal parts with heat treatment and finishing generally take longer than polymer parts.
How can you tell whether a supplier is genuinely capable?
Look at certifications, ask how they inspect output, and request test coupons along with measured property data. A capable supplier answers these questions specifically and without hesitation.