Comparison of SP, SMAT, SMRT, LSP, and UNSM Based on Treatment Effects on the Fatigue Properties of Metals in the HCF and VHCF Regimes

Abstract

This paper aims to provide a better understanding regarding the effects of shot peening (SP), surface mechanical attrition treatment (SMAT), laser shock peening (LSP), surface mechanical rolling treatment (SMRT), and ultrasonic nanocrystal surface modification (UNSM) on the fatigue properties of metals in high-cycle fatigue (HCF) and very-high-cycle fatigue (VHCF) regimes. The work in this paper finds that SMRT and UNSM generally improve the high-cycle and very-high-cycle fatigue properties of metals, while SP, SMAT, and LSP can have mixed effects. The differences are discussed and analyzed with respect to the aspects of surface finish, microstructure and microhardness, and residual stress. SMRT and UNSM generally produce a smooth surface finish, while SP and SMAT tend to worsen the surface finish on metals, which is harmful to their fatigue properties. In addition to inducing a plastic deformation zone and increasing microhardness, surface treatments can also generate a nanograin layer and gradient microstructure to enhance the fatigue properties of metals. The distribution of treatment-induced residual stress and residual stress relaxation can cause mixed effects on the fatigue properties of metals. Furthermore, increasing residual stress through SP and SMAT can cause further deterioration of the surface finish, which is detrimental to the fatigue properties of metals.

Surface Severe Plastic Deformation for Improved Mechanical/Corrosion Properties and Further Applications in the Bio-Medical and Hydrogen Sectors

“…Several review papers dealing with the fatigue behaviour of metals subjected to different types of SSPD treatments have been published recently. 89,90) Factors affecting the fatigue life of a component can be roughly divided into two main categories. First, the surface roughness or the presence of stress raisers, influence essentially the initiation stage of crack growth.…”

A Study on Surface Hardening and Wear Resistance of AISI 52100 Steel by Ultrasonic Nanocrystal Surface Modification and Electrolytic Plasma Surface Modification Technologies

“…In turn, this layer protects the surface from being worn out and damaged [7]. Moreover, the UNSM technology refines the coarse grains into nano-grains, increases the dislocation density, and segregates surface carbides [8,9].…”

Enhancing the mechanical properties of ceramics by high‐temperature rolling: A first demonstration using alumina

“…Surface treatments, such as shot peening, laser shock peening, and quenching, are universal techniques that have been widely used to enhance the strength, hardness, and fatigue performance of metals. [1][2][3][4] These techniques, developed based on the plastic deformation ability of metals, however, normally cannot be used to ceramics as ceramics are intrinsically brittle, for example, previous attempts on ceramics with shot peening demonstrated that after treating, microcracks appeared on the surface of the treated ceramics. 5 The previously reported methods, such as bioinspired microstructural design, phase transformation toughening, composite toughening, and heat treatment, however, are usually only applicable to specific ceramic systems.…”