Wear resistance of 20Cr2Ni4A alloy steel treated by laser shock peening and implantation of diamond nanoparticles

Abstract To reduce the wear of 20Cr2Ni4A alloy steel, a new method to implant diamond nanoparticles onto the surface by employing laser shock peening was presented. Studies demonstrated that with implanted diamond nanoparticles, the crater depth induced by laser shock peening was reduced by 23.7 μm. A lower surface roughness of 2.25 μm was obtained, which is 44.6% of the sample treated by laser shock peening only. The nano-hardness was as high as 4.93 GPa, which is 31% higher than the original samples. The coefficient of friction of 20Cr2Ni4A steel was reduced to 0.31 and the wear loss was reduced to 4 mg, which is only 50% of that of the original samples. The wear mechanism of the samples with implanted diamond nanoparticles was analyzed and provided new concepts and methods for solving the problem of wear failure.