Type: Addithive Constraint Brief
Related tools: AM Cost Calculator, Bottleneck Map (Gates 4 & 5)
Core Observation
As-built surface roughness increases both the machining or finishing allowance required and the difficulty of CT/NDT. Empirical comparisons of multiple finishing routes on LPBF specimens (across aluminum, titanium, stainless, and nickel alloys) show that the lowest-cost finishing step is rarely the one that minimizes total accepted-part cost once inspection yield and scrap risk are considered.
Why It Matters
Treating surface finish and inspection as separate decisions underestimates total cost and lead time. A finishing route that leaves residual roughness can raise CT false-call rates or force additional machining, offsetting any initial savings.
Practical Screening Steps
- Define the required final surface and internal inspection criteria before selecting the finishing route.
- In the Cost Calculator, vary post-process surface cost and estimated scrap rate together.
- Review Gate 5 (Inspection) in parallel with Gate 4 when internal features are present.
- Prefer finishing approaches that simultaneously improve inspectability where CT or other NDT is mandatory.
Limitations
Screening insight only. Achievable roughness, inspection detectability, and cost vary significantly by alloy, geometry, and specific finishing process. Not a substitute for application-specific testing.
Research screening aid only. Not a certified process recommendation. Not investment advice.
Leave a Reply