The whiskers added to the cemented carbide material can absorb the energy of crack propagation, and the amount of absorbed energy is determined by the bonding state between the whiskers and the matrix. The toughening mechanism of whiskers is mainly manifested as follows: (1) Whisker pull-out toughening: When the whiskers are pulled out of the matrix under external load, part of the external load energy is consumed due to interfacial friction, so as to achieve the purpose of toughening, and its toughening effect is affected by the sliding resistance of the whiskers and the interface. There must be sufficient bonding force between the whisker and the matrix interface to effectively transfer the external load to the whiskers, but not too large to maintain sufficient pull-out length. (2) Crack deflection toughening: When the crack tip encounters the second phase with an elastic modulus greater than the matrix, the crack will deviate from its original forward direction and expand along the interface between the two phases or within the matrix. Because the non-planar fracture of the crack has a larger fracture surface than the planar fracture, it can absorb more external energy, thereby acting as a toughening effect. The addition of whiskers or particles with high elastic modulus to the matrix can cause crack deflection toughening mechanisms. (3) Whisker bridging toughening: When the matrix is broken, the whiskers can withstand external loads and play a role in bridging between the broken crack surfaces. The bridged whiskers can generate a force on the matrix to close the cracks, consume external loads to do work, and thus improve the toughness of the material.