High-pressure strength of nanocrystalline tantalum carbide (TaC) studied at a non-hydrostatic compression

High-pressure strength and plastic properties of nanocrystalline tantalum carbide (nano-TaC) have been investigated by using synchrotron radiation up to 65.5   GPa. Nano-TaC shows a bulk modulus of K 0   =   433   ±   7   GPa with K ′ 0 fixed at 4.0. It is close to that of diamond and is higher than the results from micron-TaC. In its plastic deformation behavior, nano-TaC starts to yield a plastic deformation at around 20   GPa, and the yield strength of nano-TaC increases with pressures and reaches a value of ~   22   GPa at the highest pressure in our test. The high-pressure strength of nano-TaC is comparable to that of other superhard metals such as B 6 O, c-BC 2 N and γ -Si 3 N 4 . The first-principle DFT calculations confirm a lower bulk modulus for micron-TaC.