Fabrication and Characterization of Micro Dent Arrays by Laser Shock Peening on Ti-6Al-4V Surfaces

Abstract

Surface micro dents may act as lubricant reservoirs to reduce friction and wear in sliding and rolling contact applications. Surface patterning has become a valuable technique for fabricating micro dents. Alternative methods such as micromachining present obvious limitations in comparison with laser shock peening (LSP). In this paper, the use of LSP along with an automatic X-Y table proves to be an attractive and reliable method for producing micro dent arrays with enhanced surface integrity and free of cracks. Surface topography, residual stress, and microhardness of the fabricated micro dent arrays on polished Ti-6A1-4V have been characterized. It has shown that LSP is capable of efficiently fabricating mass micro dent arrays with controllable size. The center area of the peened dents has highest hardness. In addition, high compressive residual stress can also be created.

Investigation of the crater-like microdefects induced by laser shock processing with aluminum foil as absorbent layer

“…Macropits were found at laser-impacted points. This phenomenon has been observed by many researchers [13][14][15][16]. However, more importantly, another extraordinary phenomenon was observed.…”

“…Although we ideally hope that the mechanical performances of a laser-shock-processed (LSP'd) target will be improved without deteriorating its surface quality, the status of the surface do will be changed. As is well known, laser shock processing will create macropits on target surfaces, just as shot peening [13][14][15][16]. In recent years, some researchers have even used LSP to fabricate functional microdents on metal surfaces to improve the lubrication between friction pairs.…”

State-Of-Art, Challenges, and Outlook on Manufacturing of Cooling Holes for Turbine Blades

“…Tensile residual stress cannot be avoided due to the thermal nature of the LD process. Warren et al (2008) and Caslaru et al (2009) have used laser shock peening (LSP) to introduce deep subsurface compressive residual stress. Compressive residual stress is beneficial in improving fatigue life of metallic components and preventing stress corrosion cracking (Peyre et al, 2000).…”

Improving friction performance of cast iron by laser shock peening

“…It is demonstrated that LSP process utilizes the laser-shock-induced mechanical effect to improve both mechanical and physical properties of materials [10] . Caslaru et al [11] fabricated micro-dent arrays on Al6061-T6 surface by LSP and studied the effect of dent geometry on surface tribological performance. Guo et al [12] produced micro-dent arrays on the surface of Ti-6Al-4V via LSP.…”