What is the Difference Between Tungsten Carbide and Boron Carbide?

🆚 Go to Comparative Table 🆚

The key difference between tungsten carbide and boron carbide lies in their hardness, stiffness, and density. Here are the main differences between the two materials:

  • Hardness: Boron carbide is harder and stiffer than tungsten carbide. It has a Knoop hardness of 2600 to 3200, while tungsten carbide has a Knoop hardness of 1670.
  • Density: Boron carbide has a density of 2.1 to 2.7 g/cm³, while tungsten carbide has a density of 15 g/cm³.
  • Mechanical Properties: Boron carbide has a higher compressive strength (1710 to 2200 MPa) and flexural strength (170 to 410 MPa) compared to tungsten carbide (4780 MPa and 1830 MPa, respectively). However, tungsten carbide has a higher ultimate tensile strength (350 MPa) than boron carbide (350 MPa).
  • Thermal Properties: Boron carbide has a higher thermal conductivity (31 to 90 W/m-K) and thermal diffusivity (16 to 38 mm²/s) than tungsten carbide (85 W/m-K and 21 mm²/s, respectively). Both materials have similar specific heat capacities, with boron carbide ranging from 950 to 280 J/kg-K and tungsten carbide having a value of 280 J/kg-K.
  • Electrical Properties: Boron carbide has a lower electrical resistivity (0 to 11 Ω-m) than tungsten carbide (0.75 Ω-m).

Both tungsten carbide and boron carbide are non-oxide engineering ceramics with high hardness, making them suitable for use in heavy machinery and applications where strong impacts are applied. However, due to its higher hardness and stiffness, boron carbide is more wear-resistant than tungsten carbide.

Comparative Table: Tungsten Carbide vs Boron Carbide

Here is a table comparing the differences between tungsten carbide and boron carbide:

Property Tungsten Carbide (WC) Boron Carbide (B4C)
Chemical Formula WC B4C
Compressive Strength (MPa) 4780 1710 to 2200
Elastic Modulus (GPa) 630 240 to 460
Flexural Strength (MPa) 1830 170 to 410
Fracture Toughness (MPa-m1/2) 12 2.5 to 3.5
Knoop Hardness 1670 2600 to 3200
Poisson's Ratio 0.24 0.17 to 0.19
Tensile Strength: Ultimate (MPa) 350 350
Maximum Temperature (°C) 1000 1000 to 2500
Specific Heat Capacity (J/kg-K) 280 950
Thermal Conductivity (W/m-K) 85 31 to 90
Thermal Expansion (µm/m-K) 5.4 4.5 to 5.6
Electrical Resistivity (Order of Magnitude, 10x Ω-m) 0.75 0 to 11
Density (g/cm³) 15 2.1 to 2.7

Boron carbide is harder and stiffer than tungsten carbide. While both materials have similar tensile strengths, boron carbide has a lower compressive strength, flexural strength, and fracture toughness compared to tungsten carbide. Additionally, boron carbide has a higher thermal conductivity, specific heat capacity, and density than tungsten carbide.