feat(schema): thermal sub-table additions (#152)

src/pymat/properties.py

@@ -157,6 +157,23 @@ class ThermalProperties:
     min_service_temp_unit: str = "degC"
     thermal_shock_resistance: Optional[str] = None  # "excellent", "good", "fair", "poor"
 
+    # Cryogenic radiation-shielding budgets (#152) — polished Al ≈ 0.04, anodized ≈ 0.8
+    emissivity: Optional[float] = None  # 0–1, dimensionless
+    # Heat-pulse propagation (#152)
+    thermal_diffusivity: Optional[float] = None  # mm²/s
+    thermal_diffusivity_unit: str = "mm^2/s"
+    # Cryogenic embrittlement boundary (#152) — Delrin/PEEK get brittle below ~-50 °C
+    min_use_temp_K: Optional[float] = None
+    cryogenic_compatible: Optional[bool] = None
+    # NIST-style ∫k dT for cryogenic heat-leak (#152)
+    integrated_thermal_conductivity: Optional[float] = None  # W/m
+    integrated_thermal_conductivity_unit: str = "W/m"
+    # Phase-change enthalpies for liquids/coolants (#152)
+    latent_heat_fusion: Optional[float] = None  # kJ/kg
+    latent_heat_fusion_unit: str = "kJ/kg"
+    latent_heat_vaporization: Optional[float] = None  # kJ/kg
+    latent_heat_vaporization_unit: str = "kJ/kg"
+
     # T-dependent curves (#148). Sibling fields parallel to scalars.
     thermal_conductivity_curve: Optional[TempCurve] = None
     specific_heat_curve: Optional[TempCurve] = None
@@ -223,6 +240,32 @@ def min_service_temp_qty(self) -> Optional[Quantity]:
             return (self.min_service_temp + 273.15) * ureg.kelvin
         return self.min_service_temp * ureg(self.min_service_temp_unit)
 
+    @property
+    def thermal_diffusivity_qty(self) -> Optional[Quantity]:
+        if self.thermal_diffusivity is None:
+            return None
+        return self.thermal_diffusivity * ureg(self.thermal_diffusivity_unit)
+
+    @property
+    def integrated_thermal_conductivity_qty(self) -> Optional[Quantity]:
+        if self.integrated_thermal_conductivity is None:
+            return None
+        return self.integrated_thermal_conductivity * ureg(
+            self.integrated_thermal_conductivity_unit
+        )
+
+    @property
+    def latent_heat_fusion_qty(self) -> Optional[Quantity]:
+        if self.latent_heat_fusion is None:
+            return None
+        return self.latent_heat_fusion * ureg(self.latent_heat_fusion_unit)
+
+    @property
+    def latent_heat_vaporization_qty(self) -> Optional[Quantity]:
+        if self.latent_heat_vaporization is None:
+            return None
+        return self.latent_heat_vaporization * ureg(self.latent_heat_vaporization_unit)
+
     def thermal_conductivity_at(self, temp: Quantity) -> Optional[Quantity]:
         """
         Calculate thermal conductivity at given temperature.

tests/test_thermal_fields.py

@@ -0,0 +1,130 @@
+"""Tests for #152 — thermal sub-table additions.
+
+Pure additive: 7 new optional fields on `ThermalProperties` for
+cryogenic + coolant work.
+"""
+
+from __future__ import annotations
+
+from textwrap import dedent
+
+from pymat.loader import load_toml
+
+
+class TestNewThermalFields:
+    def test_emissivity_loads(self, tmp_path):
+        """Critical for cryogenic radiation shielding budgets."""
+        p = tmp_path / "m.toml"
+        p.write_text(
+            dedent("""
+            [polished_al]
+            name = "Polished Al"
+            [polished_al.thermal]
+            emissivity = 0.04
+            """)
+        )
+        m = load_toml(p)["polished_al"]
+        assert m.properties.thermal.emissivity == 0.04
+
+    def test_thermal_diffusivity_loads(self, tmp_path):
+        p = tmp_path / "m.toml"
+        p.write_text(
+            dedent("""
+            [m]
+            name = "M"
+            [m.thermal]
+            thermal_diffusivity_value = 97
+            thermal_diffusivity_unit = "mm^2/s"
+            """)
+        )
+        m = load_toml(p)["m"]
+        assert m.properties.thermal.thermal_diffusivity == 97
+
+    def test_min_use_temp_K_and_cryogenic_compat(self, tmp_path):
+        """Delrin/PEEK get brittle below ~-50 °C; track that explicitly."""
+        p = tmp_path / "m.toml"
+        p.write_text(
+            dedent("""
+            [delrin]
+            name = "Delrin"
+            [delrin.thermal]
+            min_use_temp_K = 223
+            cryogenic_compatible = false
+
+            [peek]
+            name = "PEEK"
+            [peek.thermal]
+            min_use_temp_K = 4
+            cryogenic_compatible = true
+            """)
+        )
+        mats = load_toml(p)
+        assert mats["delrin"].properties.thermal.min_use_temp_K == 223
+        assert mats["delrin"].properties.thermal.cryogenic_compatible is False
+        assert mats["peek"].properties.thermal.cryogenic_compatible is True
+
+    def test_integrated_thermal_conductivity_loads(self, tmp_path):
+        """NIST-style ∫k dT for cryogenic heat-leak calculations."""
+        p = tmp_path / "m.toml"
+        p.write_text(
+            dedent("""
+            [m]
+            name = "M"
+            [m.thermal]
+            integrated_thermal_conductivity_value = 1430
+            integrated_thermal_conductivity_unit = "W/m"
+            """)
+        )
+        m = load_toml(p)["m"]
+        assert m.properties.thermal.integrated_thermal_conductivity == 1430
+
+    def test_latent_heats_load(self, tmp_path):
+        p = tmp_path / "m.toml"
+        p.write_text(
+            dedent("""
+            [ln2]
+            name = "Liquid N2"
+            [ln2.thermal]
+            latent_heat_fusion_value = 25.7
+            latent_heat_fusion_unit = "kJ/kg"
+            latent_heat_vaporization_value = 199
+            latent_heat_vaporization_unit = "kJ/kg"
+            """)
+        )
+        m = load_toml(p)["ln2"]
+        assert m.properties.thermal.latent_heat_fusion == 25.7
+        assert m.properties.thermal.latent_heat_vaporization == 199
+
+    def test_pint_qty_for_new_dimensional_fields(self, tmp_path):
+        p = tmp_path / "m.toml"
+        p.write_text(
+            dedent("""
+            [m]
+            name = "M"
+            [m.thermal]
+            thermal_diffusivity_value = 97
+            thermal_diffusivity_unit = "mm^2/s"
+            integrated_thermal_conductivity_value = 1430
+            integrated_thermal_conductivity_unit = "W/m"
+            latent_heat_fusion_value = 25.7
+            latent_heat_fusion_unit = "kJ/kg"
+            latent_heat_vaporization_value = 199
+            latent_heat_vaporization_unit = "kJ/kg"
+            """)
+        )
+        m = load_toml(p)["m"]
+        t = m.properties.thermal
+        assert t.thermal_diffusivity_qty.to("mm^2/s").magnitude == 97
+        assert t.integrated_thermal_conductivity_qty.to("W/m").magnitude == 1430
+        assert t.latent_heat_fusion_qty.to("kJ/kg").magnitude == 25.7
+        assert t.latent_heat_vaporization_qty.to("kJ/kg").magnitude == 199
+
+
+class TestRegression:
+    def test_full_corpus_loads(self):
+        from pymat import _CATEGORY_BASES
+        from pymat.loader import load_category
+
+        for cat in _CATEGORY_BASES:
+            mats = load_category(cat)
+            assert mats, f"category {cat} loaded empty"