# 02 - Process Flow Diagrams

## Context / Goal
Generate the comprehensive Mermaid documentation of the laboratory workflow (reconstructed from the 10 Miro slides) as standalone `.md` / `.mermaid` artifacts for the final report and for human review.

## Dependencies
01 (uses volumes/terminology from lab_config.yaml).

## Task
Produce `./out/report/process_flow.md` containing the following diagrams, each also saved as a separate `.mermaid` file in `./out/report/diagrams/`.

### D1 - Coupon Assembly
```mermaid
flowchart LR
    A([Ti-6Al-4V Base 10x10x3 mm]) --> B[Cleaning]
    B --> B1([Rinsed in deionized water])
    B1 --> B2([Sonicated in cleaning solution])
    B --> C[Smearing Adhesive]
    C --> C1([Cr adhesive coating])
    C --> D[Vapor Deposition System<br/>Kurt J. Lesker PVD 200]
    D --> D1([PtAu sputter coating, gradient])
    D --> E([Test Coupon])
```

### D2 - Characterization & Batch Assembly
Test Coupon → SIMTRA (composition / atom energies) → Optical profilometry (film thickness 0.3-1.1 µm) → assemble Test Wafer (×49 coupons) → assemble Test Batch (×3 wafers) → batches 721-724 with the deposition parameter table.

### D3 - Testing tree
Friction (RAPID; Lab Air → µ_normal; Dry N2 → µ_dry_nit), Nanoindentation (TI980 → hardness, reduced modulus), AFM (topography → Ra), XRF (M4 Tornado → Pt/Au map).

### D4 - Tribometer session sequence (sequenceDiagram)
Request test → Get samples → Load samples → Load ball holders (3 counterfaces/holder) → Create Excel test plan (Sample Plate, Plate Location, Sample ID, Save Location, Folder Name, X/Y/Z Offset, Load, Iterations) → Transfer to tribometer → Set up platter → Activate software → Load plan → Activate tribometer → ... → Software stop → Save avg files → Remove plates/platters → Close software → Pull equipment out.

### D5 - Execution loop (flowchart)
```
Load all counter-faces
  FOR EACH of 5 plates
    FOR EACH of 6 probes (parallel)
      FOR EACH of 4 coupons on coupon square
        3x per coupon: draw track -> rotate counter-face
```

### D6 - Data hierarchy ERD-style
batch → wafer → coupon → {xrf_map, nanoindentation, afm, profilometry} and coupon → track → {cycles, loops, wear}; deposition → simtra_profile.

## Output
- `./out/report/process_flow.md`, `./out/report/diagrams/D1..D6.mermaid`
- Marker `./out/.done/02.ok`.
