it is anticipated that the material observes within cracks in the current study has developed as a consequence of crack face movement and internal friction. Surface RCF cracks and branches appeared to contain fine wear debris. The main cracks of the RCF cluster had a more distinct multilayers appearance of flake-like metallic material. Crack within the RCF clusters were also several millimeters long, which allow for a larger relative movement between crack faces. Hardness of the sheared layers was higher than the bulk material, and often after an indent was made small cracks initiated around the indent, along the sheared layer. This may be caused by the lamellar buildup of metal flakes and wear debris, with lower adherence between metal flakes, or the metal flakes due to high shear deformation initially having an aligned microstructure, giving anisotropic critical stress intensity in mode 1(K1c), which can facilitate cracks to propagate within them.