Sourcing Aerospace Additive Manufacturing Parts

When additive manufacturing is the right buy

Buy additive when the geometry, the part count or the schedule makes machining a poor fit. The strongest cases are parts with internal passages, several machined pieces that can be consolidated into one, and low quantities where tooling or long setups would dominate the cost.

Typical aerospace requests that suit AM:

• Manifolds, injectors and heat exchangers with internal channels that cannot be drilled
• Brackets and housings redesigned for weight, where a lattice or topology optimized shape removes material a mill could not reach
• Assemblies that are brazed or welded from several details today and can be printed as one piece, removing joints that need their own inspection
• Drill guides, check fixtures, masking and assembly aids for the shop floor and the launch pad

The common thread is that the value comes from the design. A part drawn for machining and then printed rarely saves anything.

When machining is still the better answer

If a part is a simple prismatic shape, needs tight tolerances everywhere, or will be built in steady volume, machining from certified bar or plate is usually cheaper, faster to qualify and easier to inspect. AM adds steps that machining does not have: build qualification, stress relief, often HIP, support removal and volumetric inspection.

• Tolerances and finish. As built metal surfaces are rough, so every sealing face, bore and thread on a flight part still ends up machined. If most of the part is critical surfaces, print gives you little.
• Qualification cost. On flight hardware, a new AM part may need a qualified material process, witness testing and preproduction articles before the first delivery. A machined part from a known alloy and temper carries far less of that load.
• Fatigue critical parts. Porosity and surface condition drive fatigue in printed metal. These parts can be done, but they are the most expensive kind of AM to qualify.

A useful test: ask whether the part could exist in its current form without AM. If the honest answer is yes, quote it both ways. Our aerospace CNC machining page covers what to require when machining wins.

Metal options: LPBF, DED and binder jet

Laser powder bed fusion is the default for complex flight metal parts, directed energy deposition for large parts and repair, and binder jet for cost driven parts where lower density or sintering shrinkage is acceptable. Each process has its own spec trail, so the choice affects what you can call out on the drawing.

The engineering detail behind these families, including defect types and alloy specifications, is on the metal additive manufacturing reference page.

Polymer options: ULTEM 9085, PEKK and SLS nylon

Polymer AM is the right call for interiors, ducting, covers, tooling and many GSE parts, and two filament materials cover most aerospace polymer requests. Material extrusion (often sold under the FDM name) with ULTEM 9085 or a PEKK based material handles flame, smoke and toxicity or outgassing needs. Selective laser sintering of nylon covers general purpose parts with good toughness and no support structures.

• ULTEM 9085. A polyetherimide blend that Stratasys describes as meeting multiple aerospace flame, smoke and toxicity standards. Stratasys also offers a certified grade with the traceability aircraft programs expect. It is the usual pick for aircraft interior and cabin parts.
• PEKK (Antero 800NA). A PEKK based filament. The Stratasys data sheet reports ASTM E595 results of 0.27 percent total mass loss and 0.01 percent collected volatile condensable material, and Stratasys positions it for spacecraft parts that need low outgassing and for parts exposed to jet fuel, oil and hydraulic fluid.
• SLS nylon (PA11, PA12). Good for enclosures, brackets for non structural loads, fixtures and prototypes. Check flammability and outgassing data before using it anywhere near flight hardware.

Printed polymer parts are anisotropic. The same Antero data sheet shows tensile strength in the build direction roughly half the in plane value, so state the load direction or let the supplier set the build orientation with engineering. Material data sheet values are typical values for comparison, not design allowables. Our engineering plastics page covers the wider polymer family.

Pick the qualification path before you ask for a price

The single biggest cost and schedule driver in aerospace AM is how the part will be qualified, so decide that first and put it on the RFQ. A prototype, a shop fixture and a Class A flight part can share a printer and a powder, and still differ by an order of magnitude in effort.

For NASA flight hardware, NASA-STD-6030, approved in April 2021, sets the requirements. It applies to crewed systems, Appendix B gives tailoring guidance for robotic missions, and NASA material presented in 2021 lists laser powder bed fusion, wire and blown powder DED, and polymer powder bed fusion, vat and filament processes among those it addresses. Parts are classed by consequence of failure:

MSFC-STD-3716 and MSFC-SPEC-3717, Marshall's earlier documents for laser powder bed fusion, still appear in program requirements. NASA's standards database lists MSFC-SPEC-3717 as active, and NASA presentations describe these documents as the basis NASA used for tailoring flight programs before and alongside the agency standard. If your contract invokes one of them, say so, because the supplier's qualified process has to match.

Outside NASA, industry specifications fill the same role:

For non flight parts such as tooling, prototypes and most GSE, say so plainly on the request. You can still ask for material certs and a dimensional report without paying for flight qualification.

The post processing chain is most of the job

On a metal flight part, the time on the printer is often the smaller share of the work. Expect a chain like this, and expect each step to produce a record:

1. Stress relief on the build plate, so the part does not distort when it is cut free
2. Removal from the plate by wire EDM or saw, then support removal
3. Powder removal from internal passages, with a method to prove they are clear
4. Hot isostatic pressing (HIP) where the spec or part class calls for it, to close internal porosity
5. Heat treatment to the condition the material spec requires
6. Machining of interfaces, sealing faces, bores and threads
7. Surface finishing where fatigue or flow requires it, such as abrasive flow or chemical polishing of internal channels
8. Inspection, then cleaning and packaging

Each step may happen at a different shop, which is where traceability breaks if nobody tracks serial numbers and certs across the hand offs. Heat treat and HIP records should name the cycle and the furnace. Our heat treatment reference explains what a good furnace record looks like.

Inspection: CT, witness coupons and first article

Printed parts are accepted on three kinds of evidence: the part itself, coupons built with it, and the records of the build. Ask for all three on flight work.

• Computed tomography (CT). The usual way to see internal features, trapped powder and porosity. Agree on the flaw size that matters before you buy, because CT resolution falls as part size grows.
• Witness coupons. Tensile, density, chemistry and sometimes fatigue specimens built on the same plate and processed with the part, then tested to the agreed plan.
• Surface and dimensional inspection. Dye penetrant on machined surfaces where the spec calls for it, and a dimensional report on every critical feature.
• First article. A full AS9102 first article on the first production part, and again after a change to machine, parameters, powder supplier or post processing.

The NDT methods and their limits on printed metal are covered on our nondestructive testing page, and the buyer side of first article on our AS9102 first article guide.

Powder and feedstock traceability

Require that every part can be traced to its powder or wire lot, and that reused powder is tracked as carefully as new powder. Powder picks up oxygen and changes particle size with reuse, and both affect properties.

Put these on the purchase order for metal flight parts:

• Powder or wire lot certs with chemistry, and particle size data for powder
• Reuse history for the powder in each build, and the reuse limit the supplier's process allows
• Machine identification and the parameter set used, which should not change without notice
• A build record showing plate layout, which serial numbers sat where, and any interruptions

For polymers, ask for the material lot and, on ULTEM 9085, whether the certified grade was used. The same certificate discipline used for bar and plate applies, as described on our material certs and traceability page.

Build files, export control and NDAs

Treat the CAD model and the build file as controlled technical data, not as a print job attachment. A printable model of a defense article can be all a foreign person would need to make it.

Under the ITAR, technical data at 22 CFR 120.33 includes information required for the design, development, production, manufacture or modification of defense articles, with blueprints, drawings and documentation as examples. Under the definitions, furnishing that data to a foreign person can itself be a defense service. A build file for an ITAR part sits squarely in that definition, and the same caution applies to models of items controlled under the EAR.

• State the export classification of the part and the data on the RFQ.
• Do not upload controlled models to a web portal or general file share. Use the secure transfer route on our controlled programs page, with US persons only.
• Ask the supplier where build files are stored, who can see them, and whether any machine sends data to a cloud service.

Every supplier signs a flow down NDA before seeing customer data, and suppliers do not learn the end customer unless you approve. The details are on our confidentiality page.

Outgassing for polymer parts used in vacuum

If a printed polymer part will fly on a spacecraft or sit in a vacuum chamber, ask for ASTM E595 outgassing data on the exact material. ASTM E595 measures total mass loss and collected volatile condensable material after 24 hours at 125 C under vacuum.

Historically, 1.0 percent total mass loss and 0.10 percent collected volatile condensable material have been used as screening levels for rejecting spacecraft materials, and NASA maintains a public outgassing database of tested materials. The standard itself notes that passing the screen does not guarantee a system stays uncontaminated, and your program's contamination control plan may set tighter limits or require a bakeout.

Printed parts can differ from molded resin, so where the risk matters, test parts from the actual process. If you need that testing arranged, our space test lab time page covers how we find thermal vacuum and outgassing capacity.

What drives cost and lead time

Qualification level, post processing and inspection usually move the price more than the print itself. We do not publish prices or promise lead times, but these are the drivers to expect in a quote:

• Part class and qualification. Flight parts may need a qualified process, witness testing and preproduction articles. Non flight parts do not.
• Build height and nesting. Powder bed time scales with build height, so a tall part costs machine time even if little metal is melted. Several parts nested on one plate share that time.
• Material. Titanium and nickel alloys need inert gas handling and careful powder control. Specialty alloys may need a powder buy before the build.
• HIP and heat treat. These are often batch processes at an outside vendor and run on their schedule.
• Machining. Every critical surface adds a setup, and printed parts can be awkward to fixture.
• Inspection. CT time, coupon testing and first article reporting all add days.

What to put on an additive manufacturing RFQ

Send the model and the drawing together, and state the qualification path. A complete AM request includes:

• 3D model in a neutral format plus the controlling drawing and revision
• Whether the part is flight, flight spare, GSE, tooling or prototype, and its class if NASA-STD-6030 applies
• Material and specification, or acceptable alternatives if you are open to them
• Process restrictions, such as LPBF only, or a named specification like AMS 7003 or MSFC-SPEC-3717
• Required post processing: stress relief, HIP, heat treat condition, surface finish on internal and external surfaces
• Inspection requirements: CT, witness coupons and test plan, dimensional report, AS9102 first article
• Powder lot traceability and reuse requirements
• For polymers in vacuum, outgassing requirements and any bakeout
• Quantity now and expected over the program, and the need date
• Export classification of the part and the data

Our aerospace RFQ checklist covers the fields every request needs, AM or not.

How Aerospace Sourcing handles AM requests

We do not run printers. We match your request to suppliers whose process fits the part, flow down your specifications and qualification requirements, and coordinate the outside steps such as HIP, heat treat, machining and inspection when they happen at different shops.

• One quote, one lead time, one point of contact and one purchase order, even when several shops are involved
• Your material, process, traceability and inspection requirements flowed down to each supplier
• Build records and certs checked before shipment, with a certificate of conformance on every order and other certs when the request requires them

We do not promise that a qualified AM supplier exists for every alloy and class. If we cannot find one we are comfortable with, we say so, and we will tell you if machining looks like the better route.

Request an additive manufacturing quote

Use the additive manufacturing request form. It is preset for AM, so it asks for the part class, material spec and post processing up front, which are the answers that decide whether a quote is realistic. A person replies within one business day, and rush requests are prioritized. Controlled models go through our confidentiality and secure transfer process, not the form.

Questions

Related

• Aerospace CNC Machining for Space and Defense Buyers
• AS9102 First Article Inspection: A Buyer's Guide
• Aerospace RFQ Checklist for Machined and Fabricated Parts
• Sourcing Structures, Harnesses, Cleaning and Test Time for Satellite Builders

Sources

• NASA Technical Standards: NASA-STD-6030 Additive Manufacturing Requirements for Spaceflight Systems
• NASA: NASA-STD-6030 approved baseline (PDF)
• NASA NTRS: Qualification of additively manufactured hardware, NASA-STD-6030 training
• NASA NTRS: Quality Leadership Forum 2021 AM standards briefing
• NASA Technical Standards: MSFC-SPEC-3717
• SAE: AMS7003A Laser Powder Bed Fusion Process
• SAE: AMS7004 titanium alloy preforms, plasma arc DED
• ASTM F3302 titanium alloys via powder bed fusion
• ASTM F3301 thermal post processing of PBF metal parts
• NASA GSFC: outgassing database user guide (ASTM E595 screening levels)
• Stratasys: Antero 800NA data sheet
• eCFR: 22 CFR 120.33 Technical data