Evidence
Vacuum equipment
| Red flag | Technical risk | Correct record |
|---|---|---|
| Ultimate pressure without pump-down curve | no separation between pumping capability, leaks, conductance and outgassing | pressure-time curve with chamber volume and pumping configuration |
| Nominal pump speed only | effective speed at chamber may be much lower due to duct conductance | Seff estimate or gas-load test at chamber |
| No pressure-rise test | real leak, virtual leak and outgassing are not separated | isolated chamber pressure-rise curve |
| No helium leak-test report | leak-tightness is not verified | helium leak detector record with acceptance criterion |
| FAT without raw logs | acceptance depends on undocumented snapshots | time-stamped pressure, gas, temperature and alarm logs |
PVD / CVD coatings
| Red flag | Technical risk | Correct record |
|---|---|---|
| Coating photo without cross-section | appearance does not confirm thickness, architecture or adhesion | cross-section, thickness and interface record |
| Hardness stated without load/method | value cannot be compared or reproduced | test method, load, substrate, coating thickness |
| Tribology result without counterbody and environment | friction/wear result is not transferable | load, speed, counterbody, lubrication/medium, temperature |
| Route name instead of process window | PVD/CVD label hides critical plasma, temperature and source conditions | process parameters and acceptance coupons |
| No adhesion or interface data | functional failure may occur even when coating looks uniform | scratch/indentation/adhesion data and microscopy |
Plasma nitriding / duplex treatment
| Red flag | Technical risk | Correct record |
|---|---|---|
| Nitriding claim without hardness/profile data | treated layer depth and uniformity are unknown | hardness profile, microstructure, diffusion depth |
| No part temperature record | dimension, phase state and surface quality may be affected | temperature log and fixture/load description |
| Duplex route without support-layer data | coating may fail under load despite good adhesion test | support-layer depth + coating cross-section |
| No surface roughness before/after | tribology and sealing performance may change | Ra/Rz before and after process |
LPC / vacuum heat treatment
| Red flag | Technical risk | Correct record |
|---|---|---|
| LPC recipe without carbon profile | case depth and surface carbon are not demonstrated | carbon profile and hardness profile |
| HPGQ claim without cooling data | microstructure and distortion risk are not controlled | cooling curve, gas pressure, hardness and distortion records |
| No TUS / temperature uniformity discussion | load temperature may differ from controller temperature | thermal uniformity data or load thermocouple record |
| Material certificate absent | steel response and hardenability cannot be assessed | steel grade, heat, chemistry and prior heat treatment |
Cathode / TVAC / EP test
| Red flag | Technical risk | Correct record |
|---|---|---|
| Single cathode ignition presented as validation | no stability, restart or drift information | I-V curves, restart cycles and emission drift |
| Empty-chamber base pressure used for EP test readiness | operating pressure under xenon/gas load may be too high | gas-load test and effective pumping estimate |
| No contamination-control record | optical surfaces, cathode and thruster can be affected | cleaning, witness samples and post-test inspection |
| No diagnostic layout | test may be impossible to interpret after assembly | ports, line-of-sight, feedthroughs, OES/electrical layout |
Application link
Scientific interpretation of red flags
Red flag assessment: a weak record does not prove failure. It marks where the physical mechanism, boundary condition or measurement record is insufficient for a technical decision.
| Missing record | Scientific ambiguity | Next record |
|---|---|---|
| No pressure-rise curve | Leak, virtual leak and outgassing cannot be separated. | Q = V · dP/dt with chamber state. |
| No coating cross-section | Layer thickness, interface and defect state remain unknown. | Cross-section and thickness map. |
| No hardness / concentration profile | Diffusion case cannot be tied to process route. | Depth profile and thermal record. |
| No drift / restart data | Cathode start is not separated from stable operation. | Fixed-point drift and restart cycle record. |
Basis
- Record
- Missing or weak checks: no cross-section, no pressure-rise test, no raw logs, no profile, no stability data.
- Interpretation
- Red flags identify where a claim is under-supported or technically ambiguous.
- Project use
- A red flag does not prove failure; it marks where further records are needed.