The radiation shielding properties of pure Tungsten

The radiation shielding properties of pure Tungsten can not be fully exploited in small and complex shapes because of the cost and difficulty to machine mechanically pure Tungsten. The addition of Copper and Nickel powders to Tungsten powder improves the machinability of Tungsten Heavy Alloy (WHA), that is a fully dense material with unique thermal and mechanical properties associated to sizeable radiation shielding properties, typical of pure Tungsten

Spectra-Mat has over 50 years of experience in using high temperature powder metallurgy of Tungsten powders to manufacture highly homogeneous WHA, where Tungsten grains are uniformly embedded into the Nickel-Copper phase. Spectra-Mat is not using any organic binders so the final material is vacuum compatible and is compliant to ASTM B777.

Material Thermal Expansion
(ppm/K) between 50
and 400 C
Thermal Conductivity
(W/m*K) at 25 C
Density (g/cc) Hardness
(Rockwell C)
Yield Strength at
0.2% offset (PSI)
W/Ni/Cu 90/6/4 wt% 6.2 70 17.0 24 80000
W/Ni/Cu 95/3.5/1.5 wt% 5.2 75 18.2 27 85000
  • Homogeneous material in 3 directions with no voids on the surface.
  • Vacuum compatible because of low outgassing.
  • Not magnetic.
  • Uniform Gold plating.
  • Mechanical tolerances of final parts better than 0.001” (0.025 mm).
  • Engineering support to design the suitable collimators and radiation shields geometry.

Although the density approaches that of tungsten, unlike tungsten WHA is readily machinable and displays superior mechanical properties as well as low thermal expansion:

  • The high density enables WHA’s superior performance compared to lead and other lead replacements in radiation shielding, x-ray and γ-ray collimation. Other uses include gyroscopic components, boring bars and armor piercing projectiles
  • The low expansion coefficient allows WHA to be compatible with certain glasses (pyrex), semiconductors (InP, InSb, Ge, GaP), metals (Kovar) and ceramics (alumina, sapphire and aluminum nitride)


  • X-ray and γ-ray radiation shielding/ attenuation
    components such as collimators for medical,
    industrial and security applications
  • Low thermal expansion coefficient materials for optoelectronics and fiber optics applications
  • Low thermal expansion coefficient materials for silicon power electronics
  • Kinetic energy penetrators
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