ForMatter/Materials/metal/Tantalum (Pure)
mat_tantalum_pure

Tantalum (Pure)

refractory metal, anodizable, biocompatible · Ta
highlast updated 2026-04-28

Tantalum sits between platinum and titanium in the cultural memory of jewelry — heavier, denser, and grayer than titanium, grayer and cheaper than platinum. Anodizes to color the way niobium does. Resistant to nearly every acid except hydrofluoric. The metal capacitor electrolytes are made of, repurposed for wedding bands when somebody wanted something other than tungsten without the platinum cost.

BCC structure, density 16.65 g/cm³ — denser than steel and approaching gold. Melting point 3017 °C, fourth-highest among metals (after tungsten, rhenium, osmium); among all elements only carbon also exceeds it. Hypoallergenic and biocompatible (used in surgical implants since the 1940s), corrosion-immune to all common reagents except HF and SO₃. Vickers ~100 HV annealed. Anodizes electrolytically to structurally-colored Ta₂O₅ films across 0–150 V.

Mechanical

  • tensile strength (annealed) · MPa220
  • yield strength (annealed) · MPa180
  • hardness Vickers (annealed)100
  • density · kg/m³16650
source: ASM Handbook Vol. 2; H.C. Starck datasheet

Thermal

  • melting point · °C3017
  • thermal conductivity · W/m·K57
source: CRC Handbook

Sustainability

  • embodied carbon · kg CO₂e/kg360
  • recyclabilitymoderate — specialty-refiner recoverable; supply-chain ethics complicated by conflict-mineral history (3T-tantalum)
  • biodegradableFalse
  • certificationsASTM F560 (medical implant grade), RMI conflict-free smelter program
  • localityprimary mining concentrated in DRC, Rwanda, Brazil, Australia
source: Editorial estimate from ICE / Granta CES EduPack class databases — industry mean, with cradle-to-gate boundary unless otherwise noted. Embodied carbon for any specific product depends on supplier mix, recycled content, and energy grid; verify against a primary source before using these numbers in a sustainability claim.
visual
blue-gray as polished, distinctly cooler-toned than titanium
tactile
noticeably heavy for its volume
weight perception
heavy

PBR starter values

finish · iridescent — open for table, JSON, host snippets, downloads

Principled BSDF defaults derived from the sphere iridescent finish. Reasonable seed for Blender, Substance, Keyshot, Rhino — tune per material. Or grab the whole library at once: ForMaterials library →

# finish:                   iridescent
albedo                      #5a6878
metallic                    0.30
roughness                   0.20
ior                         1.45
transmission                0.00
clearcoat                   0.60
sheen                       0.00
anisotropic                 0.00
iridescence                 1.00
iridescence_ior             1.30
iridescence_thickness_min   100
iridescence_thickness_max   800
thickness                   0.60
attenuation_distance        0.40
emissive_intensity          0.07
copy as JSON 
{
  "albedo": "#5a6878",
  "metallic": 0.3,
  "roughness": 0.2,
  "ior": 1.45,
  "transmission": 0.0,
  "clearcoat": 0.6,
  "sheen": 0.0,
  "anisotropic": 0.0,
  "iridescence": 1.0,
  "iridescence_ior": 1.3,
  "iridescence_thickness_min": 100,
  "iridescence_thickness_max": 800,
  "thickness": 0.6,
  "attenuation_distance": 0.4,
  "emissive_intensity": 0.07
}
Blender 4.x Python 
# Blender 4.x — Principled BSDF
# Tantalum (Pure) · finish: iridescent
import bpy
mat = bpy.data.materials.new(name="mat_tantalum_pure")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.1022, 0.1384, 0.1878, 1.0)
bsdf.inputs["Metallic"].default_value           = 0.300
bsdf.inputs["Roughness"].default_value          = 0.200
bsdf.inputs["IOR"].default_value                = 1.450
bsdf.inputs["Transmission Weight"].default_value = 0.000
bsdf.inputs["Coat Weight"].default_value        = 0.600
bsdf.inputs["Sheen Weight"].default_value       = 0.000
bsdf.inputs["Anisotropic"].default_value        = 0.000
KeyShot Python (lux) 
# KeyShot 11+ — lux Python API, Generic material
# Tantalum (Pure) · finish: iridescent
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_tantalum_pure", materialType="Generic")
mat.setProperty("diffuse",      (90, 104, 120))   # 8-bit sRGB
mat.setProperty("metallic",     0.300)
mat.setProperty("roughness",    0.200)
mat.setProperty("indexOfRefraction", 1.450)
mat.setProperty("transparency", 0.000)
mat.setProperty("coatingWeight", 0.600)
Substance pbrMetalRough 
{
  "_format": "Substance Designer / Painter \u2014 pbrMetalRough constants",
  "_about": "Tantalum (Pure) \u00b7 finish: iridescent",
  "baseColor": {
    "r": 0.1022,
    "g": 0.1384,
    "b": 0.1878
  },
  "metallic": 0.3,
  "roughness": 0.2,
  "ior": 1.45,
  "opacity": 1.0,
  "anisotropyLevel": 0.0,
  "_notes": "Channels listed are the standard Substance pbrMetalRough output. Drop into a Uniform Color node per channel, or as the constant input on a layered stack."
}
glTF 2.0 Metallic-Roughness 
{
  "asset": {
    "version": "2.0",
    "generator": "ForMatter"
  },
  "materials": [
    {
      "name": "mat_tantalum_pure",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.1022,
          0.1384,
          0.1878,
          1.0
        ],
        "metallicFactor": 0.3,
        "roughnessFactor": 0.2
      },
      "extensions": {
        "KHR_materials_ior": {
          "ior": 1.45
        },
        "KHR_materials_clearcoat": {
          "clearcoatFactor": 0.6
        },
        "KHR_materials_iridescence": {
          "iridescenceFactor": 1.0,
          "iridescenceIor": 1.3,
          "iridescenceThicknessMinimum": 100,
          "iridescenceThicknessMaximum": 800
        }
      }
    }
  ]
}
USD Preview Surface 
# USD Preview Surface — UsdShade.MaterialLook prim attributes
# Tantalum (Pure) · finish: iridescent
def Material "mat_tantalum_pure" {
    token outputs:surface.connect = </mat_tantalum_pure/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.1022, 0.1384, 0.1878)
        float   inputs:metallic     = 0.300
        float   inputs:roughness    = 0.200
        float   inputs:ior          = 1.450
        float   inputs:opacity      = 1.000
        float   inputs:clearcoat    = 0.600
        token   outputs:surface
    }
}
↓ download glTF material
ProcessAnodizing · Laser Cutting · CNC Milling
Substitutes
Niobium (Pure)
Platinum 950 (Pt950)
Finishes that suit this material
Titanium / niobium color anodize · iridescent

Second life

repairabilitymoderate — tantalum welds in inert atmosphere; specialty bench operation outside major-shop equipment.
recyclabilityhigh — tantalum scrap is high-value; small specialty recyclers (Cabot, Global Advanced Metals) recover for capacitor and aerospace re-use.
disposal pathspecialty refractory-metals recycler.
typical longevity300 years (typical)
failure modes
  • hydrogen embrittlement at sustained stress + atomic-hydrogen
  • gallium-attack contamination from contact with gallium alloys (the canonical specialty failure)
  • oxidation at sustained 250+ °C

ASM Handbook Vol. 2: Refractory Metals; Cabot tantalum technical literature.

Citations

Further reading