Additive Manufacturing Qualification

Additive Manufacturing Qualification (manufacturing-quality/additive/additive-manufacturing-qualification)

Use when the task is qualifying an additive manufacturing (AM) process for aerospace production: powder bed fusion or directed energy deposition parameter set definition, volumetric energy density verification, witness coupon sample planning, material property verification, and first article checks for AM parts.

Domain quick reference

• AM parameter set: layer height, laser power, scan speed, hatch spacing. The four build parameters pin the energy input to the melt pool for a powder bed fusion or directed energy deposition build.
• Volumetric energy density: VED = laser power / (scan speed x hatch spacing x layer height), in J/mm^3 with W, mm/s, mm, mm. A build parameter change without VED re-verification is a qualification gap.
• Witness coupons: test coupons built with the same parameter set and machine as the production parts. The sample plan maps material property tests (tensile, fatigue, hardness) to coupon counts, with one spare coupon per test type for re-test.
• Material property verification: coupon test results recorded against the parameter set; a missing test or an out-of-specification result blocks qualification.
• First article checks for AM parts: build file traceability, machine id, parameter set match, coupon results, dimensional report, and any required non-destructive examination.
• AS9100 link: AM process qualification sits under production control and quality management; AS9100 is referenced, not reproduced.

Workflow

1. Define the AM parameter set: layer height, laser power, scan speed, hatch spacing. build_parameter_set() records the four parameters and computes the volumetric energy density.
2. Size the witness coupon sample plan: witness_coupon_count() returns the coupon count from the material property sample plan (total samples plus one spare coupon per test type).
3. Verify material properties: record coupon test results against the parameter set.
4. Run the first article checks for the AM part: build file, machine, parameter set match, coupon results, dimensional report, and NDT.
5. Assemble the qualification record and check completeness: build_qualification_record() and validate_record() flag any missing field (parameter_set, witness_coupon_plan, material_property_verification, first_article_inspection).
6. Validate inputs first: non-numeric or non-positive build parameters, malformed sample plans, and malformed records raise ValueError instead of returning a silent result.

Pitfalls

• Confusion with special-process-qualification: the general special process qualification record (PQR) governs welding, heat treatment, and NDT processes with a validity interval; this leaf qualifies AM parameter sets with energy density and coupon evidence. An AM build is qualified by parameters and coupons, not by a PQR-style interval.
• Confusion with as9102/first-article-inspection: the AS9102 FAI forms remain the general first article inspection program. The AM first article checks here are build-specific (build file, machine, parameter set match, coupon results) and feed the FAI; they do not replace it.
• Unit mixing: VED in J/mm^3 needs W, mm/s, mm, mm. Converting the scan speed to m/s or the hatch spacing to cm changes the result by orders of magnitude.
• Missing hatch spacing: energy density computed from three of the four parameters is undefined, not approximate.
• Coupon count vs specimen count: the sample plan maps tests to coupons; the count includes the spare coupon per test type so a re-test does not require a new build.
• Energy density outside the qualified envelope: a parameter change can keep parts dimensionally acceptable while pushing VED outside the qualified window; re-verify before production runs.

Behavior contract (gate 3)

The qualification logic is exercised by the gate 3 contract test: scripts/test_additive_manufacturing_qualification.py against scripts/additive_manufacturing_qualification_logic.py (stdlib unittest, offline). Run: python3 scripts/test_additive_manufacturing_qualification.py

Compliance

• Standards referenced, not reproduced: AS9100 frames AM process qualification within production control; summary-only per standards-map.yaml.
• compliance: STANDARDS-REF, gated: false.