Effect of laser shock peening on wear behaviors of TC11 alloy at elevated temperature

Surface, Subsurface and Tribological Properties of Ti6Al4V Alloy Shot Peened under Different Parameters

“…This contrasting result is possibly because of the formation of undesirable microstructural defects such as micro-cracks and porosities due to the intensity of the plastic deformation caused by peening with S60 shots. It is known that the amount of plastic deformation during shot peening is closely related to the kinetic energy of particles [ 80 ] as a function of particle size and particle velocity/impingement pressure [ 78 , 79 ]. That being said, further characterisation may be needed to validate this explanation.…”

“…An increasing shot size largely affected the microstructural features as well as the hardness ( Figure 3 and Figure 4 ); however, the effect of peening time (5 min vs. 15 min for S60) was less important on changing the microstructural features and was insignificant in hardness improvement ( Figure 4 ). As the amount of plastic deformation caused by shot peening is strongly dependent on the kinetic energy of particles [ 80 ], some studies report that higher kinetic energy can be achieved with large shots compared to that of the small shots [ 79 , 83 ]. To sum up, in the present study, the kinetic energy of the shots may not have been sufficient to deform the layers below approximately 120 µm depth for S10 shots and approximately 550 µm depth for S60 shots ( Figure 4 ).…”

“…All wear tracks consisted of a material pile-up with smearing, formation, and breakdown of oxide layers ( Figure 11 ); and, local grooves have been formed by micro-ploughing ( Figure 10 ). The material pile-up via smearing (as in Figure 10 ) usually occurs with the plastic deformation due to the sliding contact of the ball [ 80 ]. The fragmentation of both the worn material and the oxide layers can occur during the dry sliding [ 105 , 106 , 107 ], which could behave like hard debris particles during the contact.…”

“…As adhesion, abrasion, and oxide wear mechanisms have been generally reported in the literature on the tribological behavior of Ti and its alloys [ 3 , 80 , 105 , 108 ], it has been stated that the dominant wear mechanism changes with different mechanical surface treatments. These dominant wear mechanisms can be evaluated depending on two factors: (1) the modification of surface microstructure and mechanical properties; and, (2) tailored surface topography.…”

“…The cross-sectional image of the wear tracks of shot peened sample with S10 ( Figure 13 b), similar to the reference sample ( Figure 13 a) showed the formation of wear marks, the presence of the oxide layer, and microstructural change occurring in the wear affected area. A slight material pile up on the edges of the wear track can be seen in the worn surface topography of the reference sample [ 76 ] ( Figure 14 a), which highlights the plastic deformation taken place during the dry sliding conditions [ 3 , 7 , 80 ]. This agreed well with the cross-sectional SEM results of the wear tracks since even the subsurface microstructure of the reference sample was modified due to contact during dry sliding tests ( Figure 13 a) [ 7 ].…”