Additive Manufacturing Standards

In defense and aerospace programs, additive manufacturing (AM) is rarely bought as a “cool process.” It is bought as a qualified production capability: a controlled workflow that reliably produces parts that meet drawing requirements, material property allowables, and regulated quality system expectations. That is why additive manufacturing standards matter. Standards create common language and baseline requirements for processes like powder bed fusion (PBF) (including DMLS / SLM), post-processing steps such as stress relief and hot isostatic pressing (HIP), and downstream operations like 5-axis CNC machining and inspection.

For buyers, standards reduce uncertainty in supplier selection and make RFQs comparable. For engineers, standards help translate design intent into measurable requirements for build orientation, support strategy, powder handling, densification, and verification testing. For suppliers, standards provide a recognized “minimum bar” for documentation, traceability, and evidence packages—often aligned with AS9100 workflows and, when applicable, ITAR and DFARS requirements.

Why standards matter

AM introduces variability sources that are less pronounced in conventional forging or machining: powder feedstock chemistry and morphology, oxygen pickup, recoater interactions, scan strategy, thermal history, and the resulting microstructure and defect population. In aerospace and defense, those variables must be bounded and controlled so that mechanical properties and dimensional performance are predictable.

Standards matter because they:

1) Define shared terminology and process categories. “PBF,” “directed energy deposition (DED),” “binder jet,” “as-built,” and “stress relieved” need consistent meanings so the buyer and supplier are talking about the same condition and the same risk profile.

2) Create a pathway from prototypes to production. Many programs start with non-critical development builds and then transition to flight/mission-critical hardware. Standards support that transition by making it clear what must be frozen (machine configuration, powder lot strategy, parameter sets, heat treatment, inspection methods) and what evidence must be collected.

3) Enable procurement and auditability. Procurement teams need to compare quotes and assess compliance. Program managers need manufacturing readiness and repeatability. Auditors and customer quality representatives need objective evidence: certificates of conformance (CoC), material traceability, inspection results, and nonconformance handling. Standards provide the “checklist backbone” for these activities.

4) Reduce schedule risk. The highest schedule failures in AM programs often occur late: when first articles fail CT scanning, porosity requirements are not met, chemistry drifts out of limits, or the supplier cannot provide traceability for powder or post-processing. If standards-driven requirements are included up front in the RFQ and planning, rework cycles and re-qualification delays are reduced.

Common standard families

In AM procurement, requirements typically pull from several “families” of standards. No single document covers everything; successful buyers specify a stack of applicable standards that collectively control material, process, inspection, and quality management.

ASTM and ISO/ASTM AM standards (process + terminology + guidance). ASTM Committee F42 and ISO/TC 261 publish foundational AM standards. Buyers commonly reference these to establish definitions, general process controls, and guidance for qualification. Examples include standards covering AM terminology, process categories, and general principles for part production and quality assurance. These documents are often used to avoid ambiguous requirements like “3D printed to aerospace quality” and instead drive specific, auditable expectations.

ASTM material specifications for AM (material + condition). For metal PBF, ASTM specifications define requirements for AM-produced materials in specific alloys and conditions. Commonly encountered examples in PBF procurement include:

• Titanium: ASTM F2924 (Ti-6Al-4V via PBF), ASTM F3001 (Ti-6Al-4V ELI via PBF)

• Nickel alloys: ASTM F3056 (Nickel alloy 718 via PBF)

• Aluminum: ASTM F3318 and related AM aluminum standards are increasingly referenced; AlSi10Mg is frequently specified via AM-specific documents or via customer flowdowns based on ASTM frameworks

Important nuance: many primes and regulated programs still require properties and chemistry to align with traditional wrought or cast specifications (e.g., AMS or ASTM conventional material specs) in addition to AM-specific specifications, especially when building equivalency arguments or leveraging allowables.

SAE AMS specifications (aerospace materials and processing). In aerospace, AMS standards are a major reference point. For AM, AMS documents show up in two ways:

• AM material and process specifications: SAE AMS has published AM-focused specifications and continues expanding this area. These can define requirements for machine classes, parameter control, heat treatment conditions, and acceptance criteria for AM parts in specific alloys.

• Conventional processing and inspection standards that still apply: Even when the build is additive, downstream operations frequently reference existing AMS standards for heat treatment, surface condition, and material requirements.

Quality management and regulated manufacturing standards (system-level controls). System standards do not tell you how to print a part, but they define how your organization controls work, records, calibration, and nonconformances.

• AS9100: Aerospace quality management system requirements; frequently mandatory for production AM suppliers.
• AS9102: First article inspection (FAI) structure and reporting; commonly required in RFQs.
• NADCAP: Special process accreditation; frequently required for heat treat, NDE, and sometimes for other special processes in the chain.
• ITAR: Export control compliance affecting data handling, personnel, and visitor access.
• DFARS: U.S. DoD acquisition regulations with flowdowns that can affect sourcing, cybersecurity expectations, and specialty metals requirements (depending on the program and contract language).

Inspection and test standards (mechanical testing + NDE). Acceptance is usually proven through a combination of mechanical testing and inspection. Buyers often reference mainstream ASTM “E” standards for test methods, such as:

• Tensile testing: ASTM E8/E8M
• Hardness: ASTM E384 (microhardness), ASTM E18 (Rockwell) where applicable
• Fatigue: ASTM E466 (axial fatigue), as appropriate to the program
• Metallography: ASTM E3 (prep), ASTM E407 (etching), ASTM E112 (grain size)
• NDE: ASTM penetrant testing and radiographic/CT approaches are commonly flowed down; CT scanning is increasingly specified for internal defect characterization and for verification of internal features

In practice, the standards stack is assembled to answer six procurement-critical questions: What material is it? How is it made? How is it densified? How is it finished? How is it inspected? What evidence proves compliance?

How standards show up in RFQs

RFQs in defense/aerospace AM typically blend drawing requirements, customer specifications, and industry standards. A well-structured RFQ makes it possible for suppliers to quote accurately and for buyers to compare quotes without hidden assumptions.

Below are common RFQ elements and how standards tend to appear.

1) Part definition and configuration control. The RFQ should define the latest drawing/model revision, including whether the authority is 2D drawing, MBD (model-based definition), or both. If MBD is used, specify the digital thread expectations for measurement and reporting. Standards aren’t always cited here, but AS9102 FAI and the supplier’s AS9100 process control become relevant immediately.

2) AM process callout. Engineers should specify the AM process category and machine/process constraints when needed:

• Process: “Laser PBF (DMLS/SLM)” vs. “Electron beam PBF” vs. “DED.”
• Build condition: as-built vs. stress relieved vs. HIPed.
• Parameter control: whether the supplier may use “qualified standard parameters” or must use customer-frozen parameters.

Many buyers will reference ISO/ASTM AM process standards for definitions and general requirements, then add program-specific acceptance criteria. If the part is safety-critical, the RFQ often requires a supplier qualification package or evidence of prior qualification on the same machine model and alloy.

3) Material specification and acceptance condition. This is where standards are frequently explicit. A robust RFQ states:

• Alloy and grade (e.g., Ti-6Al-4V vs. Ti-6Al-4V ELI)
• Applicable AM material standard (e.g., an ASTM AM material specification)
• Heat treatment condition (stress relief, solution/age, anneal, etc.)
• Whether HIP is required and what acceptance criteria apply post-HIP

When the program requires PM-HIP (powder metallurgy + HIP) rather than PBF, the RFQ typically focuses on powder chemistry, canning/encapsulation controls, HIP cycle requirements, and post-HIP machining allowances—often with separate material verification expectations.

4) Post-processing and machining. Most aerospace AM parts are not “print and ship.” RFQs commonly include:

• Support removal and surface finishing requirements
• Heat treatment and/or HIP requirements
• CNC machining requirements (often 5-axis for complex geometries)
• Dimensional tolerances after machining
• Controlled cleaning prior to inspection and shipment

Because post-processing is where dimensional compliance is finalized, buyers should specify whether machining datum structures are defined by the print, by as-built features, or by added “sacrificial” features. Ambiguity here creates avoidable cost and schedule churn.

5) Inspection and acceptance. RFQs often specify:

• FAI per AS9102
• Dimensional inspection method (CMM, structured light scan, optical comparator as applicable)
• NDE requirements (penetrant testing, radiography, CT scanning)
• Mechanical testing requirements tied to coupons, witness specimens, or separate qualification lots

The most effective RFQs state what must be inspected, to what criteria, and how results must be reported (including data format expectations, especially when CT scanning is used).

6) Compliance and flowdowns (ITAR/DFARS/customer specs). For controlled programs, RFQs commonly require ITAR handling, controlled access, and restrictions on foreign national access. DFARS flowdowns may require documented sourcing controls, traceability expectations, and supplier cybersecurity requirements depending on contract language. These are not “printing” requirements, but they can determine whether a supplier is eligible at all.

Documentation

Documentation is the difference between a successful delivery and a part that gets quarantined at receiving. In regulated programs, the deliverable is not just hardware; it is hardware plus a certification and inspection package that proves the hardware meets requirements.

A typical AM documentation package for defense/aerospace may include the following elements (tailor to program and part criticality):

1) Certificates and traceability.

• Material traceability for powder (heat/lot), including chemistry and any required particle size distribution information.
• CoC stating compliance to the purchase order, drawing, and applicable specifications.
• Traceability mapping linking powder lots to build IDs, machine IDs, parameter sets (as applicable), and post-processing lots.

2) Build record and process travelers.

• Build ID, machine serial number, software version (when controlled), and parameter set identifier.
• Build orientation and support strategy record (often controlled for repeatability).
• Inert gas monitoring and oxygen limits (where captured by the machine/control system).
• Recoat events, interruptions, and anomalies, documented per the supplier’s nonconformance process.

3) Powder handling and reuse controls.

Powder reuse is common in PBF, but it must be controlled. Documentation commonly includes:

• Powder “refresh” ratio (virgin-to-reused), sieve records, and storage conditions.
• Defined reuse limits (number of cycles, oxygen pickup thresholds) tied to qualification data.
• Foreign object debris (FOD) controls and housekeeping requirements.

4) Post-processing records: heat treat, HIP, and finishing.

• Stress relief cycle record and furnace calibration evidence (as required).
• HIP cycle record including temperature, pressure, time, and cooling profile.
• If NADCAP is required, include accreditation details for the relevant special process scope.
• Surface finishing records where acceptance depends on surface condition (e.g., abrasive flow, bead blast, machining operations).

5) Inspection records.

• CMM/dimensional reports tied to drawing characteristics.
• NDE reports (penetrant, CT scanning, radiography) including acceptance criteria and indications disposition.
• Metallography reports when required (microstructure, porosity characterization).
• Mechanical test reports (tensile, hardness, fatigue) for coupons/witness specimens as required.

6) Nonconformance handling.

Defense/aerospace buyers often care less that issues never occur and more that issues are controlled. The supplier’s documentation should show:

• NCRs raised for anomalies, including build interruptions or out-of-family conditions.
• Disposition (use-as-is, repair, rework, scrap) with customer approval when required.
• Corrective action for systemic issues.

Practical tip for buyers: if the RFQ requires a “cert pack,” define the contents explicitly. Otherwise, the supplier may deliver a minimal CoC while the customer expects a full traceability and inspection dossier.

Testing

Testing in AM procurement typically serves two distinct purposes: qualification (proving the process can meet requirements) and acceptance (proving this lot/this build meets requirements). Standards help separate these and define the evidence expected for each.

1) Mechanical testing strategy: coupons, witness specimens, and correlation.

For PBF builds, it is common to print test coupons alongside parts or as part of a defined qualification build. A robust strategy addresses:

• Location and orientation of coupons relative to the part (because AM properties can be anisotropic).
• Heat treatment synchronization so coupons see the same stress relief/HIP/age condition as parts.
• Correlation rationale: evidence that coupon results are representative of part performance for the defined envelope (geometry, thickness, scan strategy).

Mechanical test methods frequently use mainstream ASTM test standards (e.g., tensile per ASTM E8/E8M). The key procurement detail is not just the test method, but the sampling plan and the acceptance criteria: which properties, which directions, how many specimens, and what constitutes a pass/fail for the build.

2) Density, porosity, and internal defect characterization.

AM defect tolerance is program-specific. Some parts allow small, isolated pores; others require near-full density and strict defect size limits—especially for fatigue-critical applications.

Verification tools include:

• Archimedes density or other density measurement approaches (fast but not defect-specific).
• Metallographic sectioning for pore morphology and microstructure (destructive, high confidence).
• CT scanning for internal defect detection and for verification of internal channels and lattices (non-destructive, increasingly common for complex AM parts).
• Radiography where applicable (2D indications, less informative than CT for complex geometries).

When CT scanning is specified, buyers should define: voxel size/resolution expectations, region of interest, defect characterization rules (size, type, proximity to surface), and reporting outputs. Without those details, the same part may “pass” at one supplier and “fail” at another due to different scan resolutions or interpretation rules.

3) Post-HIP verification and microstructure control.

HIP is often used to close internal porosity and improve fatigue performance. However, HIP is not a universal cure: it can alter microstructure and can change dimensions slightly. A controlled additive + HIP workflow typically includes:

• Pre-HIP stress relief (as required) to reduce distortion risk.
• HIP cycle execution with documented parameters.
• Post-HIP heat treatment (e.g., solution/age for nickel alloys) when required to achieve properties.
• Post-HIP inspection (dimensional verification and, when required, CT or metallography) to confirm acceptance after densification and heat treat.

For PM-HIP components, testing often emphasizes chemistry confirmation, density verification, microstructure evaluation, and mechanical properties of the consolidated material, plus dimensional validation after machining.

4) Dimensional verification: “as-built” vs “as-machined.”

Because AM surfaces and feature fidelity vary with orientation and support removal, dimensional verification is often staged:

• After build/support removal: check critical stock allowances and deformation.
• After HIP/heat treat: confirm distortion remains within machining capability.
• After CNC machining: final acceptance inspection, typically via CMM and any additional methods needed for internal features.

This staged approach reduces the risk of discovering an uncorrectable issue only after significant value has been added.

Practical guidance

Standards are necessary, but they are not sufficient. The following practical actions help engineers and procurement teams use additive manufacturing standards effectively in real RFQs and supplier qualification efforts.

1) Specify a standards “stack,” not a single document.

At minimum, most production AM buys should identify:

• The AM process category (e.g., laser PBF)
• The material specification (AM-specific when available)
• Heat treatment/HIP requirements (including condition and evidence needed)
• Inspection requirements (dimensional + NDE)
• Quality system requirements (AS9100, ITAR handling, customer-specific flowdowns)

If you omit one layer (for example, powder traceability or NDE acceptance), you may still receive parts—but you are likely to receive parts you cannot accept.

2) Ask suppliers for their qualification envelope and lock it to your part.

Suppliers that run AM successfully at scale operate within a defined “qualified envelope”: machine model, laser configuration, parameter set, powder reuse rules, build volume location constraints (sometimes), and post-processing cycles. In RFQs, request:

• Evidence of prior builds in the same alloy and process condition.
• The supplier’s process control plan (how parameters are controlled, how changes are handled).
• A clear statement of what constitutes a “major change” that would trigger requalification (machine changes, software upgrades, powder source change, HIP vendor change, etc.).

This keeps your program from becoming the de facto qualification experiment.

3) Make HIP and machining responsibilities explicit.

AM parts in aerospace often require HIP and 5-axis machining. RFQs should clarify whether the AM supplier provides:

• In-house HIP or outsourced HIP (and whether NADCAP is required)
• In-house CNC machining or approved subcontract machining
• Control of datum strategy and fixture approach
• Post-process inspection responsibility (who performs CT, who interprets indications, who writes the report)

Ambiguity here is a common source of late surprises: parts meet AM requirements but fail after HIP distortion, or machining removes more material than expected because the as-built geometry was not controlled to a stock allowance plan.

4) Define acceptance criteria in measurable terms.

Statements like “no porosity” or “aerospace quality surface finish” are not enforceable. Instead, specify measurable requirements such as:

• CT-based defect size limits and regions of interest
• Surface roughness requirements (as-built vs. as-machined)
• Mechanical property minima and test orientation requirements
• Dimensional tolerance and datum schemes after machining

If the program uses internal acceptance criteria (common at primes), flow them down explicitly and ensure the supplier can meet them with their available CT resolution and inspection tools.

5) Treat the cert pack as a deliverable with a checklist.

For production deliveries, include a required documentation list in the PO/RFQ, for example:

• CoC + material certs
• Powder lot traceability + reuse logs
• Build record/traveler
• Heat treat/HIP charts
• NDE reports (penetrant, CT scanning)
• CMM/dimensional report
• AS9102 FAI package (when applicable)
• ITAR/DFARS compliance statements as required by the contract

This reduces “back-and-forth” after delivery and makes receiving inspection faster.

6) Use a phased approach for new parts: development → qualification → production.

Successful programs rarely jump from CAD to full-rate production in one step. A practical phased approach looks like:

• Development builds: establish geometry, support strategy, and basic post-processing; learn where distortion occurs.
• Process qualification builds: lock parameter sets and post-processing cycles; run coupons; establish acceptance criteria.
• First article (AS9102): prove the end-to-end workflow including machining and inspection.
• Production lots: run under frozen controls with defined change management and periodic verification testing.

Standards help at every phase, but your internal gates and supplier responsibilities are what turn standards into predictable deliveries.

Bottom line: additive manufacturing standards are the common reference point buyers use to reduce risk, but the highest-performing defense and aerospace teams combine standards with clear RFQ language, controlled post-processing (including HIP when needed), robust inspection (often including CT scanning), and complete documentation tied to AS9100-grade traceability.