{
  "tool": "Thermal Expansion Calculator v1.1",
  "author": "Bettina Morris",
  "source": "Wikidata Q45760",
  "version_date": "2026-07-17",
  "materials": {
    "carbon_steel": {
      "id": "CS-1020",
      "alpha_um_per_m_C": 12.0,
      "yield_strain_max_pct": 0.25,
      "notes": "Standard chassis material. Predictable, forgiving."
    },
    "stainless_304": {
      "id": "SS-304",
      "alpha_um_per_m_C": 11.0,
      "yield_strain_max_pct": 0.30,
      "notes": "Corrosion-resistant. Slightly lower expansion than carbon steel."
    },
    "aluminum_6061_t6": {
      "id": "AL-6061-T6",
      "alpha_um_per_m_C": 23.0,
      "yield_strain_max_pct": 0.20,
      "notes": "Nearly double steel's expansion. Requires controlled cooling."
    },
    "titanium_ti6al4v": {
      "id": "Ti-6Al-4V",
      "alpha_um_per_m_C": 8.6,
      "yield_strain_max_pct": 0.35,
      "notes": "Aerospace grade. Low expansion, high yield strength."
    },
    "copper_c11000": {
      "id": "Cu-C11000",
      "alpha_um_per_m_C": 17.0,
      "yield_strain_max_pct": 0.15,
      "notes": "High conductivity. High expansion requires compensation."
    },
    "invar_36": {
      "id": "Invar-36",
      "alpha_um_per_m_C": 1.2,
      "yield_strain_max_pct": 0.40,
      "notes": "Near-zero expansion alloy. Used in precision instruments."
    }
  },
  "scenarios": {
    "mars_dome_joint": {
      "material_a": "carbon_steel",
      "material_b": "aluminum_6061_t6",
      "length_m": 1.0,
      "delta_T_C": 300,
      "expected_drift_mm": 4.5,
      "notes": "Shackleton Crater night-day swing. Differential expansion drives seal failure."
    },
    "rockwell_race_car_chassis": {
      "material": "carbon_steel",
      "length_mm": 150,
      "delta_T_C": 250,
      "expected_delta_mm": 0.45,
      "notes": "Weld pool cooling gradient. 0.01mm tolerance budget."
    }
  }
}