Is Tungsten Carbide Stronger Than Tungsten?

Yes, tungsten carbide is generally stronger than pure tungsten. Tungsten carbide is a compound made by combining tungsten with carbon to form a very hard and durable material. This compound exhibits exceptional hardness, wear resistance, and strength, making it suitable for various industrial applications, including cutting tools, abrasives, and jewelry.

Tungsten already has a large elastic modulus, one larger than most steels; tungsten carbide has an even greater elastic modulus, showing its impressive rigidity. Generally, materials stiffness correlates with a large elastic modulus, and the values shown in Table 1 prove why tungsten carbide is second only to diamond in elastic resilience. Its elastic modulus is almost 700 GPa, which is on the heels of diamond (elastic modulus of 1000 GPa), which shows both its resistance to deformation as well as its tendency to shatter when worked.

The shear modulus is the ratio of shear stress to shear strain within a test specimen and is often referred to as the modulus of rigidity. It is inexorably connected to elastic modulus, as they are derived from the same equations and are both measures of rigidity (one is in response to elastic, or linear stresses, versus shear, or cross-sectional stresses). The values in Table 1 are yet more evidence to show the impressive resistance tungsten provides. For reference, most steels have a shear modulus around 80 GPa, which is only half that of tungsten and a third that of tungsten carbide’s shear modulus.

Most designers select materials based on their strength, naturally. Both tungsten and tungsten carbide are known to be rugged, extremely tough metals – so why are their tensile strengths so low? The answer is due to these materials being brittle by nature and shows an interesting material science phenomenon. Due to their molecular rigidity, brittle materials are much, much stronger in compression than they are in tension (think brick walls: they can bear thousands of pounds in compression but have you ever seen a brick truss before?). This principle becomes clear when examining the compressive strength of these materials, especially the less metallic tungsten carbide: it has a compressive strength of 2683 MPa at room temperature and retains its strength through extreme temperature changes. This same characteristic cannot be said for steel, where its compressive strength is first of all much lower and secondly, fluctuates based on temperature. Knowing this fact, it is abundantly clear that tungsten should never be used in tensile applications but is a top contender in compressive applications.