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Low‐plasticity burnishing (LPB) has been widely used in various industries. In the LPB process, when the ball moves on the material surface, plastic deformation or cold working occurs in the burnished region. Through this process, not only can LPB improve the surface integrity of metallic material components by replacing polishing in some situations, but it can also improve fatigue performance thanks to the low work hardening and the beneficial compressive residual stress (CRS). So far, extensive research has demonstrated the influence of the LPB process on surface integrity and service performance of different metallic materials, such as titanium alloys, aluminum alloys, magnesium alloys, nickel‐based superalloys, stainless steels, and carbon steels. Recent years have witnessed many innovative LPB processes and novel applications. Herein, the working principle of the LPB process is first restated. Following that, how LPB strengthens the material surface and thereby influences the mechanical performance, including the surface quality, residual stress, microstructure, microhardness, fatigue, and wear performance, is reviewed. Furthermore, the difference of surface‐strengthening effect among LPB and other surface mechanical strengthening processes is compared. Finally, the current challenges to LPB are discussed and some suggestions on its development directions are put forward. [ABSTRACT FROM AUTHOR]

[Display omitted] • Severe plastic deformation behavior of AM repaired Ti-6Al-4V alloy samples subjected to LA-UNSM treatment was thoroughly investigated. • Sufficient grain refinement, with a mix of elongated and ultra-fine grains, was produced on the surface of the LA-UNSM sample, eliminating larger columnar grains. • Improved roughness, hardness, compressive stress, and fatigue life were achieved after LA-UNSM treatment. • Fatigue life was enhanced by LA-UNSM's work hardening and dynamic precipitation effects. Ultrasonic nanocrystal surface modification (UNSM) combined with localized laser heating (LA) were implemented to enhance the surface fatigue life of additively repaired Ti-6Al-4V alloy parts in this study. The effect of induced surface severe plastic deformation on microstructure development and grain refinement is analyzed. The results showed that surface metallurgical defects, hardness, residual stress, and roughness were significantly improved after LA-UNSM treatment. As a result of the improved surface textures and higher grain refinement, the fatigue life of the LA-UNSM treated samples was an order of magnitude longer. Surface free of pores and displaying a healthy topography provides evidence. [ABSTRACT FROM AUTHOR]

Microstructure inhomogeneity is imparted into the surface of a Vit1b Zr-based bulk metallic glass (BMG) using ultrasonic nanocrystal surface modification (UNSM). As a result, compressive residual stresses with a maximum magnitude of 1130 MPa were induced in the near-surface region. Substantial improvements in both fracture strain and strength were observed for the treated specimen in three-point bending tests. The microstructure inhomogeneity and free volume generated by severe plastic deformation resulted in increased shear band density during three-point bending tests, which is evidenced by the vein-like pattern observed on the fracture surface of the treated specimen. Moreover, the enrichment of shear bands can cause the interaction between shear bands and can thus obstruct their propagation, leading to work-hardening behavior. High magnitude compressive residual stresses are also believed to impede and slow down the propagation of the shear bands. The synergistic effect of induced inhomogeneity, increased free volume and compressive residual stresses improves the fracture stress and strain of the UNSM-treated BMG. [ABSTRACT FROM AUTHOR]

[Display omitted] • UNSM refined the martensite laths and formed a plastically deformed layer on A100 steel. • Higher surface hardness and higher fretting wear resistance were observed. • High magnitude compressive residual stresses were generated in the near surface region. • Both the plain fatigue and fretting fatigue resistance of A100 steel were improved. In this study, ultrasonic nanocrystal surface modification (UNSM) was used to improve plain and fretting fatigue properties of A100 steel. Results showed that an obvious plastic deformation layer was induced in A100 steel, and the martensite microstructure was remarkably refined. In addition, surface compressive residual stress after UNSM treatment was enhanced to 1700 MPa due to the severe lattice distortion. The increased surface hardness and the presence of beneficial compressive residual stresses after UNSM treatment significantly enhanced the plain/fretting fatigue resistance of A100 steel by retarding fatigue crack nucleation and propagation. [ABSTRACT FROM AUTHOR]

• A refined and distorted lath martensite structure was generated on the surface of 300M steels through UNSM. • UNSM significantly induced high surface hardness and compressive residual stresses. • UNSM treated 300M steels exhibited higher wear resistance by forming a surface plastic deformation layer. In this study, the effects of ultrasonic nanocrystal surface modification (UNSM) treatment on the surface integrity, microstructures and wear resistance of 300M ultra-high strength steel (300M steel) were investigated. The results showed that surface roughness of 300M steels after UNSM processing was significantly decreased with a lower scanning speed even though the surface roughness values were higher than that of mechanically polished control samples. In addition, the surface hardness of 300M steel was significantly enhanced as the static load increased. It was found that using a static load of 50 N and a scanning speed of 250 mm/min in the UNSM process can significantly improve surface hardness (797 HV) while slightly increasing the surface roughness. With these parameters, the resulting microstructure of UNSM-processed samples have three layers: the layer of severe plastic deformation, the layer with gradual plastic deformation, and the unaffected layer. Due to the plastic deformation, greater and deeper compressive residual stresses were induced in the UNSM-processed samples. In addition, the wear resistance of UNSM-processed samples was significantly improved, which was attributed to the refined martensite laths, work hardening and compressive residual stress. [ABSTRACT FROM AUTHOR]