The influence of low energy laser peening on fatigue lives of Ti-6Al-4V was investigated. Laser peening was carried out on Ti-6Al-4V samples. Laser peened samples were characterized by residual stress analysis, surface roughness measurements, X-ray diffraction, optical microscopy, nanoindentation hardness tests, scanning and transmission electron microscopy and fatigue testing. Laser peening resulted in the formation of nanocrystallites on the surface and near surface regions with associated increase in hardness and introduction of compressive residual stress. Owing to positive influence of nanostructured surface and compressive residual stress, fatigue lives of the laser peened samples were significantly increased compared to the unpeened samples.

S. Ganesh Sundara Raman

Department of Metallurgical and Materials Engineering

S. Anand Kumar

R. Sundar

H. Kumar

R. Kaul

K. Ranganathan

S. M. Oak

L. M. Kukreja

K. S. Bindra

Fatigue of materials

Fatigue testing

Hardness

Nanostructured materials

Residual stresses

Scanning electron microscopy

Stress analysis

Surface roughness

Titanium alloys

Transmission electron microscopy

X ray diffraction

Compressive residual stress

LASER PEENING

Low energy laser

Nano-indentation hardness

NANOSTRUCTURED SURFACE

NEAR SURFACE REGIONS

Scanning and transmission electron microscopy

TI-6 AL-4 V

Aluminum

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Influence of laser peening on microstructure and fatigue lives of Ti–6Al–4V

Transactions of Nonferrous Metals Society of China (English Edition)

The paper presents a study of the surface and subsurface characteristics induced by laser peening without coating (LPwC) and dual shot peening (DSP) on the duplex aged Ti-15 V-3Al-3Cr-3Sn alloy. In 3D-optical topography analysis, DSP resulted in a six-fold enhancement in the surface roughness (Sa). Whereas, LPwC resulted in unaltered surface roughness (Sa) compared to the polished/unpeened sample. In cross-sectional microstructure studies, deformed grains and heat affected zones were observed in the near surface region of shot peened, and laser peened samples respectively. Moreover, compared to bulk hardness, shot peening and laser peening has resulted in maximum increment of ~28% and ~12% in microhardness of the near peened surface region respectively. © 2020, Springer Nature Singapore Pte Ltd.

Lecture Notes in Mechanical Engineering Advanced Surface Enhancement

A Comparison of Surface and Sub-surface Features Induced by Shot Peening vs. Laser Peening on a Duplex Aged Beta Ti Alloy

The titanium alloy Ti-6Al-4V was subjected to laser peening (without coating) at power densities of 3, 6 and 9 GW cm−2. The cross sectional profiles of microhardness and residual stress indicated softening in the bulk (away from the surface) at power density of 9 GW cm−2. This behavior was analyzed using a combination of Zerilli-Armstrong phenomenological model in conjunction with the concept of adiabatic heating. The implications of this analysis was supported by structural changes in terms of α → β transition (analyzed through synchrotron radiation) and microstructural changes in terms of primary α (equiaxed) to secondary α (lamellar) transformation, which is observed for the first time here. Based on this, optimum levels of peening to improve fatigue lives are suggested through relevant experiments. © 2019 Elsevier Ltd

Optics & Laser Technology

Mechanical properties of a laser peened Ti-6Al-4V

This work deals with the influence of laser peening on the fretting wear behavior of Ti-6Al-4V. Laser peening was carried out on Ti-6Al-4V. The laser-peened surface was characterized by transmission electron microscopy. Surface roughness, nanoindentation hardness, residual stress, and tensile properties of the material in both laser-peened and unpeened conditions were determined. Fretting wear tests were conducted at different normal loads using a ball-on-flat contact geometry. Laser peening resulted in the formation of nanocrystallites on the surface and near-surface regions, increased hardness, and compressive residual stress. Laser peening did not affect the tensile properties and surface roughness significantly. There was no considerable difference between the values of the tangential force coefficient of laser-peened and unpeened samples. The fretting scar size, wear volume, and wear rate of laser-peened specimens were lower than those of unpeened samples. This may be attributed to an increase in surface hardness due to strain hardening and grain refinement at the surface and near-surface regions, higher compressive residual stress, and higher resistance to plastic deformation of laser-peened samples. © 2012 Copyright Taylor and Francis Group, LLC.

Tribology Transactions

Fretting Wear Behavior of Laser Peened Ti-6Al-4V

Acta Materialia

Self-toughening crystalline Cu/amorphous Cu–Zr nanolaminates: Deformation-induced devitrification

Surface Engineering

Studies on laser peening using different sacrificial coatings

Optics and Lasers in Engineering

Studies on laser peening of spring steel for automotive applications

Bimodal nanocrystallization of NiTi shape memory alloy by laser shock peening and post-deformation annealing

Influence of laser peening on microstructure and fatigue lives of Ti-6Al-4V

Journal	Transactions of Nonferrous Metals Society of China (English Edition)
Publisher	Nonferrous Metals Society of China
ISSN	10036326
Open Access	No