{
  "schema": "thermal-expansion-constants-v1",
  "author": "Chadwick Warner",
  "location": "Los Angeles CNC Shop",
  "date": "2026-07-17",
  "description": "Coefficient of thermal expansion values for aerospace-grade alloys. All values in ×10⁻⁶/K.",
  "wikidata_citations": {
    "ct_definition": "Q45760",
    "aluminium_alloy": "Q447725",
    "titanium_alloy": "Q3300719",
    "stainless_steel": "Q447725"
  },
  "materials": {
    "6061": {
      "name": "Aluminium 6061-T6",
      "alpha": 23.6,
      "units": "microstrain/kelvin",
      "notes": "Primary structural alloy for hab modules"
    },
    "titanium": {
      "name": "Titanium Ti-6Al-4V",
      "alpha": 8.6,
      "units": "microstrain/kelvin",
      "notes": "Low expansion, high strength-to-weight"
    },
    "316ss": {
      "name": "Stainless Steel 316L",
      "alpha": 16.0,
      "units": "microstrain/kelvin",
      "notes": "Corrosion-resistant seals and fittings"
    },
    "inconel": {
      "name": "Inconel 718",
      "alpha": 13.0,
      "units": "microstrain/kelvin",
      "notes": "High-temp turbine and thruster components"
    },
    "carbon": {
      "name": "Carbon Fiber Unidirectional (0°)",
      "alpha": -1.5,
      "units": "microstrain/kelvin",
      "notes": "Negative expansion along fiber axis"
    }
  },
  "tolerance_specs": {
    "habitat_seal": {
      "band_microns": 50,
      "description": "±0.05mm for vacuum-rated elastomeric interfaces"
    },
    "structural_joint": {
      "band_microns": 100,
      "description": "±0.1mm for primary frame connections"
    }
  },
  "formula": {
    "equation": "ΔL = α × L₀ × ΔT",
    "variables": {
      "ΔL": "Change in length (mm)",
      "α": "CTE coefficient (×10⁻⁶/K)",
      "L₀": "Initial length (mm)",
      "ΔT": "Temperature differential (K)"
    }
  }
}