DOCSLIB.ORG

Characterization of Laser Peening- Induced Effects on a Biomedical Ti6al4v Alloy by Thermoelectric Means

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Characterization of Laser Peening- Induced Effects on a Biomedical Ti6al4v Alloy by Thermoelectric Means View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Digital.CSIC Characterization of laser peening- induced effects on a biomedical Ti6Al4V alloy by thermoelectric means Hector Carreón Sandra Barriuso Juan Antonio Porro Jose Luis González-Carrasco José Luis Ocaña Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 09/23/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Optical Engineering 53(12), 122502 (December 2014) Characterization of laser peening-induced effects on a biomedical Ti6Al4V alloy by thermoelectric means Hector Carreón,a,* Sandra Barriuso,b Juan Antonio Porro,c Jose Luis González-Carrasco,b,d and José Luis Ocañac aInstituto de Investigaciones Metalúrgicas, UMSNH-IIM, Edif. “U” C.U., 58000-888 Morelia, Mexico bCentro Nacional de Investigaciones Metalúrgicas, CENIM-CSIC, Avenida Gregorio del Amo 8, 28040 Madrid, Spain cUniversidad Politécnica de Madrid, Ctr. Láser UPM, 28040 Madrid, Spain dCentro Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, 28029 Madrid, Spain Abstract. Laser peening has recently emerged as a useful technique to overcome detrimental effects associ- ated with other well-known surface modification processes such as shot peening or grit blasting used in the biomedical field. It is worthwhile to notice that besides the primary residual stress effect, thermally induced effects might also cause subtle surface and subsurface microstructural changes that might influence corrosion resistance and fatigue strength of structural components. In this work, plates of Ti-6Al-4V alloy of 7 mm in thick- ness were modified by laser peening without using a sacrificial outer layer. Irradiation by a Q-switched Nd-YAG laser (9.4-ns pulse length) working at the fundamental 1064-nm wavelength at 2.8 J∕pulse and with water as a confining medium was used. Laser pulses with a 1.5-mm diameter at an equivalent overlapping density of 5000 cm−2 were applied. Attempts to analyze the global-induced effects after laser peening were addressed by using the contacting and noncontacting thermoelectric power techniques. © 2014 Society of Photo-Optical Instrumentation Engineers (SPIE) [DOI: 10.1117/1.OE.53.12.122502] Keywords: laser shock peening; thermoelectric measurements; Ti-6Al-4V; biomaterial. Paper 140177SSP received Jan. 29, 2014; revised manuscript received Mar. 21, 2014; accepted for publication Apr. 8, 2014; pub- lished online Jun. 11, 2014. 1 Introduction including shot size and shape, velocity, coverage, impinge- Titanium and its alloys are extensively used in the aeronau- ment angle, etc. Because each shot impacts the surface at a tics, medical, and engineering industries due to their intrinsic random location, peening for sufficient time to achieve uni- form surface coverage results in many multiple impacts pro- properties, such as light weight, high strength to weight ratio, 1–5 corrosion resistance, biocompatibility, and excellent high- ducing a highly cold worked surface layer. Gravity shot temperature properties. Surface engineering of titanium peening utilizes the same mechanism as conventional air- alloy components, used as biomaterials, provides a means blast but employs fewer impacts by larger shot, resulting by which the desirable bulk properties are retained in con- in a less cold worked surface layer. In conventional roller junction with enhanced fatigue strength. In addition, efforts burnishing, a hard cylindrical roller is pressed into the sur- to improve the osseointegration, fixation, and stability of tita- face of an axisymmetric work piece with sufficient force to nium base implants have been addressed by creating a rough deform the near surface layers. Roller burnishing is per- topography that increases the surface area available for bone/ formed with multiple passes, usually under increasing implant apposition. Various surface processing technologies load for improved surface finish and deliberate cold working are applied in order to achieve this goal of surface treatment of the surface. Fatigue enhancement is attributed to improved finish, increased yield strength due to cold working, and the modification. Almost all existing methods of surface development of a compressive surface layer. In conventional enhancement are currently available to develop a layer of ball burnishing, a fixed (nonrotating) ball is held in contact compressive residual stress following mechanical tensile with the moving work piece surface under a normal force deformation. The methods differ primarily in how the surface sufficient to deform the surface of the work piece. A smooth is deformed (roughness) and in the magnitude and form of surface is achieved, but with extensive cold work and the the resulting residual stress and cold work (plastic deforma- potential for surface damage and residual tensile stress. tion) distributions developed in the surface layers. The high friction and shear forces produced can cause sur- For example, conventional air-blast shot peening is gen- face damage even when lubricants are used. erally applied to steel, titanium, and nickel alloys. High Laser shock processing (also known as laser peening), an velocity impact of each particle of shot produces a dimple alternative surface processing technology, has been success- with a region of compression in the treated zone. Typical fully applied for surface enhancement of titanium alloys.6,7 compressive residual stress distributions reach a maximum Irradiation by a Q-switched high-power laser pulse induces approaching the alloy yield strength, and extend to a high pressure plasma (several gigapascals), which produces depth of 0.05 to 0.5 mm. The magnitude of compression high amplitude shock waves.8 To protect irradiated surfaces achieved depends primarily upon the mechanical properties from thermal rise, sacrificial layers can be used. Irradiating of the alloy. The depth of the compressive layer and the water-immersed surfaces (1 to 10-mm water thickness) en- degree of cold working depend upon the peening parameters, able a factor 5 to 10 intensification of the shock amplitude by *Address all correspondence to: Hector Carreon, E-mail: [email protected] 0091-3286/2014/$25.00 © 2014 SPIE Optical Engineering 122502-1 December 2014 • Vol. 53(12) Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 09/23/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Carreón et al.: Characterization of laser peening-induced effects on a biomedical Ti6Al4V alloy. a trapping-like effect on the plasma, although this method along the sample. The Seebeck coefficient, S, is defined as has the practical disadvantage of possible premature water the ratio between the voltage, ΔV, developed along the dielectric breakdown and is normally substituted by a sample and the temperature difference, ΔT, given by water jet curtain method.9 Laser shock processing produces S ¼ ΔV∕ΔT as shown in Fig. 1(a). a layer of compression of comparable magnitude to shot Recently, this method was used in a noncontacting way peening, but much deeper with less cold works without com- by detecting the magnetic field produced by thermoelectric promising the surface roughness. Moreover, this process is currents in metals; this is the called noncontacting thermo- not restricted by component geometry, as is the case with electric technique.16–22 Let us assume that we have a defect or deep rolling. imperfection in an otherwise homogeneous material and a Recently, experimental results reported by Carreon temperature gradient is established throughout the specimen. et al.10–12 indicate that the stress-dependence of the thermo- Because of this temperature gradient, different points at the electric power (TEP) in metals produces sufficient contrast to boundary between the defect or imperfection and the host detect and quantitatively characterize regions under com- material will be at different temperatures, therefore at differ- pressive residual stress based on their thermoelectric contrast ent thermoelectric potentials. These minor thermoelectric with respect to the surrounding intact material. Also, it was potential differences will drive local thermoelectric currents demonstrated that the thermoelectric method is entirely around the affected area producing a flux magnetic density insensitive to surface topography while it is uniquely sensi- given by B, which can be detected in a noncontacting way by tive to subtle variations in thermoelectric properties, which a high sensitive magnetometer as shown in Fig. 1(b). This are associated with the different material effects induced by technique was originally suggested for the detection of met- different surface modification treatments. The goal of this allic inclusions in the material but was subsequently shown research work is to use two nondestructive thermoelectric to be sensitive enough to sense subtle changes in the TEP of techniques, the noncontacting and contacting TEP measure- metals due to plastic deformation and the presence of ments, to sense the subsurface changes induced by laser residual stresses.21,22 peening in a metallic biomedical Ti-6Al-4V alloy. 3 Material and Thermoelectric Methods 2 TEP Phenomena In this section, the experimental setup and the procedure Thermoelectricity is caused by coupled transport of heat and used to detect and quantify subsurface changes on Ti-6Al- electricity in metals, which leads to a number of interesting 4V alloy by thermoelectric means will be described. A sur- phenomena,
Load more

Recommended publications
  • High-Power Solid-State Lasers from a Laser Glass Perspective
    LLNL-JRNL-464385 High-Power Solid-State Lasers from a Laser Glass Perspective J. H. Campbell, J. S. Hayden, A. J. Marker December 22, 2010 Internationakl Journal of Applied Glass Science Disclaimer This document was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor Lawrence Livermore National Security, LLC, nor any of their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or Lawrence Livermore National Security, LLC. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or Lawrence Livermore National Security, LLC, and shall not be used for advertising or product endorsement purposes. High-Power Solid-State Lasers from a Laser Glass Perspective John H. Campbell, Lawrence Livermore National Laboratory, Livermore, CA Joseph S. Hayden and Alex Marker, Schott North America, Inc., Duryea, PA Abstract Advances in laser glass compositions and manufacturing have enabled a new class of high-energy/high- power (HEHP), petawatt (PW) and high-average-power (HAP) laser systems that are being used for fusion energy ignition demonstration, fundamental physics research and materials processing, respectively. The requirements for these three laser systems are different necessitating different glasses or groups of glasses.
    [Show full text]
  • MECA SENS 2017 Programme& Abstracts
    9th International Conference on Mechanical Stress Evaluation by Neutron and Synchrotron Radiation Hosted by the South African Nuclear Energy Corporation (Necsa) SOC Limited in cooperation with the International Atomic Energy Agency (IAEA) & ABSTRACTS PROGRAMME MECA SENS 2017 Programme & Abstracts MECA SENS 2017 Local Organising Committee Contents Committees 2 Foreword 2 Local Organising Committee 3 Programme Advisory Committee 3 International Scientific Committee 4 Sponsors 5 Event Information 6 Location 6 Registration 9 Internet 9 Catering 9 Presentations 10 Poster session 10 Certificate of attendance 10 Community outreach 10 Programme 11 Spring School - Monday 18 Sept 11 Day 1 – Tuesday 19 Sept 12 Day 2 – Wednesday 20 Sept 13 Day 3 – Thursday 21 Sept 14 List of Abstracts 15 Alain Lodini Plenary Lecture 23 Keynote Presentations 24 Invited Presentations 26 Oral Presentations 42 Poster Presentations 91 School lectures 114 List of Attendees 122 Author Index 126 1 | MECA SENS 2017, Skukuza, South Africa Committees Foreword Dear colleagues On behalf of the Organising Committee, it is a great privilege to welcome and receive you at the Nombolo Mdhluli Conference Centre in the Skukuza Rest Camp, capital of the UNESCO Biosphere Kruger National Park for the proceedings of MECA SENS 2017. This conference continues the tradition of providing a vibrant interactive forum for scientists, students and engineers interested in the most recent developments and capabilities of diffraction based techniques, complemented by mechanical and image-based methods towards rendering information on the prevailing stress conditions and material performance. We thank all participants for submitting excellent contributions. This has enabled the assembly of an exciting scientific program for the next three days.
    [Show full text]
  • Laser Peening Without Coating: Process, Effects and Applications
    LASER PEENING WITHOUT COATING: PROCESS, EFFECTS AND APPLICATIONS Y. Sano 1, N. Mukai 1, M. Obata 1 1 Toshiba Corporation, 8 Shinsugita-cho Isogo-ku Yokohama 235-8523, Japan ABSTRACT This paper reviews the current status of research, development and application on laser peening without coating (LPwC). LPwC imparts compressive residual stress on material by irradiating laser pulses under aqueous environment without any surface preparation. LPwC can be operated without restriction on absorption by water, using water-penetrable green lasers. The effect penetrates 1mm or more, much deeper than that of conventional surface treatment such as shot peening. Accelerating stress corrosion cracking (SCC) tests showed that LPwC effectively prevented the initiation of SCC in sensitized austenitic stainless steels, nickel-based alloys and their weld metals. LPwC remarkably improved high-cycle fatigue properties of steels, aluminum alloys, titanium alloys. Retardation of crack propagation due to stress corrosion and fatigue was also confirmed. LPwC has been utilized to prevent SCC in Japanese nuclear power plants (NPPs) since 1999. KEY WORDS Laser peening, Residual stress, Stress corrosion cracking, Fatigue INTRODUCTION Recent advances in laser material processing have yielded a multitude of innovative processes and applications in various fields. Laser peening without coating (LPwC) is a typical example and blazed a trail in preventive maintenance for SCC in operating nuclear power plants (NPPs), taking full advantage of the inertia-less process over mechanical treatment (Sano, 2000a). LPwC was invented about a decade ago as a surface enhancement technology to introduce compressive residual stress on materials, while exploring new applications of copper vapor lasers (Konagai, 1995).
    [Show full text]
  • 2014 Year in Review
    NEWSLINE 2014 YEAR IN REVIEW LAWRENCE LIVERMORE NATIONAL LABORATORY NOTE NEWSLINE: LOOKING BACK AT 2014 CONTENTS Top 10 science and technology stories of 2014 Top 10 science stories . 2 n 2014, Lawrence Livermore National Laboratory (LLNL) built on a 62-year tradition January . 4 of translating basic science into technologies that ensure national security, address February . 7 I pressing real world problems and expand the boundaries of fundamental science. TOP March . 10 April . 13 The top stories of the year are a reflection of the Laboratory’s ability to apply its core May . 16 national security competencies to a broad set of rapidly evolving national and global 10 June . 19 challenges, including: energy, climate change, biodefense and detection, forensic July . 23 science, high performance computing and materials science. August . 26 September . 29 The capabilities developed and applied to this research, such as high performance computing (HPC) and additive October . 32 manufacturing, also serve to enhance the nation’s economic vitality and global competitiveness. November . 36 December . 41 Because evaluating the long-term impact of recent scientific developments on a field of study or science Recognition and Awards . 44 in general is difficult at best, the following advances are not listed in order of scientific importance. These This issue of Newsline was produced by the Public represent only a sampling of the science and technology produced at Lawrence Livermore during the 2014 Affairs Office. It represents a sample of the science and technology, people and operations highlights of calendar year. the year. It is available on the LLNL website. On the cover: Top stories of the year.
    [Show full text]
  • Effective Simulation and Optimization of a Laser Peening Process BE ACCEPTED in PARTIAL FULFILLMENT of the REQUIREMENTS for the DEGREE of Doctor of Philosophy
    Effective Simulation and Optimization of a Laser Peening Process A dissertation submitted in partial fulfillment of the requirements for the degree of the Doctor of Philosophy By GULSHAN SINGH B.S., Jai Narain Vyas University, Jodhpur, India, 2001 M.Tech., Indian Institute of Technology, Kanpur, India, 2003 2009 Wright State University Wright State University SCHOOL OF GRADUATE STUDIES August 10, 2009 I HEREBY RECOMMEND THAT THE DISSERTATION PREPARED UN- DER MY SUPERVISION BY GULSHAN SINGH ENTITLED Effective Simulation and Optimization of a Laser Peening Process BE ACCEPTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Doctor of Philosophy . Ramana V. Grandhi, Ph.D. Dissertation Director Ramana V. Grandhi, Ph.D. Director, Engineering Ph.D. Program Joseph F. Thomas, Jr., Ph.D. Dean, School of Graduate Studies Committee on Final Examination Ramana V. Grandhi, Ph.D. Nathan Klingbeil, Ph.D. Ravi Penmetsa, Ph.D. Allan H. Clauer, Ph.D. Robert Brockman, Ph.D. ii Abstract Singh, Gulshan, Ph.D. in Engineering Program, Wright State University, 2009. Effective Simulation and Optimization of a Laser Peening Process. Laser peening (LP) is a surface enhancement technique that has been applied to improve fatigue and corrosion properties of metals. The ability to use a high energy laser pulse to generate shock waves, inducing a compressive residual stress field in metallic materials, has applications in multiple fields such as turbomachinery, airframe structures, and medical appliances. In the past, researchers have investigated the effects of LP parameters experimentally and performed a limited number of simulations on simple geometries. However, monitoring the dynamic, intricate relationships of peened materials experimentally is time consuming, expensive, and challenging.
    [Show full text]
  • Thursday, May 10, 2007
    ROOM 318-320 ROOM 321-323 ROOM 324-326 ROOM 314 ROOM 315 ROOM 316 ROOM 317 ROOM 336 CLEO JOINT C LEO QELS 8:00 a.m. – 9:45 a.m. 8:00 a.m. – 9:45 a.m. 8:00 a.m. – 9:45 a.m. 8:00 a.m. – 9:45 a.m. 8:00 a.m. – 9:45 a.m. 8:00 a.m. – 9:45 a.m. 8:00 a.m. – 9:45 a.m. 8:00 a.m. – 9:45 a.m. CThA • Fundamentals of CThB • Novel JThA • Attosecond CThC • χ2/Cascaded χ2 CThD • Optical Polymers CThE • Spectral Control of QThA • Novel Dynamic QThB • Plasmonics I Femtosecond Laser/ Semiconductor Laser Dynamics Devices Warren N. Herman; Lab Solid-State Lasers Measurements in Metals Mikhail Noginov; Norfolk Material Interactions Cavities Presider to Be Announced Robert Fisher; R. A. Fisher for Physical Sciences, Hajime Nishioka; Inst. for Michael Woerner; Max- State Univ., USA, Presider Donald Harter; IMRA Richard Jones; Intel Corp., Associates, USA, Presider Univ. of Maryland, USA, Laser Science, Japan, Born-Inst., Germany, America Inc, USA, USA, Presider Presider Presider Presider Presider Tutorial Invited Invited Tutorial Invited CThA1 • 8:00 a.m. CThB1 • 8:00 a.m. JThA1 • 8:00 a.m. CThC1 • 8:00 a.m. CThD1 • 8:00 a.m. CThE1 • 8:00 a.m. QThA1 • 8:00 a.m. QThB1 • 8:00 a.m. Ultrafast Micro and Nanomachining, Nanoscale Semiconductor Plasmon La- Probing Proton Dynamics in Molecules Parametric Generation in AlGaAs/AlOx Biomimetic Optical Polymers, James Widely Tunable Yb:KYW Laser Locked Ultrafast Spectroscopy on Photonic Nano-Particle Ions and Atoms, Nabil Gerard Mourou; Ecole Polytechnique de sers, Farhan Rana1, Christina Manolatou1, on an Attosecond Time Scale, Sarah Waveguides: Performances and Perspec- Shirk1, Guy Beadie1, Richard S.
    [Show full text]
  • Laser Peening Fact Sheet
    Hepburn and Sons LLC “Trusted advisors to the American Maritime Industry” TECHNOLOGY FACT SHEET – Laser Shock Peening TECHNICAL CHALLENGE 10X Compressive residual stress • Aluminum shipbuilding on the rise in the Navy, leading to benefits over other peening materials problems like stress corrosion cracking (SCC) and methods and treatments sensitization • Repair yards tasked with these substantial repairs • Aluminum repair has significant rework, as it is difficult to work with • Welding repairs impart large stresses on and deform the 48X aluminum SCC on aluminum ship Lifetime extension of • Flame straightening not permitted on marine grade aluminum superstructure sensitized aluminum when laser shock peened versus • Common aluminum forming methods are laborious, costly, and no treatment time-consuming TECHNOLOGY OVERVIEW • High-energy pulsed laser directed at material surface to generate pressure pulses • Shock wave plastically yields and cold works the 1-5 mm material to generate deep compressive stresses Range of compressive residual stress depth as a • Residual stress layers are orders of magnitude result of laser shock peening deeper than that achievable with shot peening • Highly predictive and deterministic stress Laser peening a metal surface profiles • Used successfully in the aerospace industry for nearly 20 years • Significantly improves aluminum lifespan • 20 years Arrests crack growth and mitigates stress Length of time that laser corrosion cracking shock peening has been successfully used in the • Mitigates aluminum sensitization
    [Show full text]
  • Laser Peening for Prevention of Fatigue Failures
    LASER PEENING FOR PREVENTION OF FATIGUE FAILURES David F. Lahrman Peter A. Gaydos LSP Technologies, Inc. United States ABSTRACT Laser peening is an innovative commercially-available surface enhancement process for increasing the fatigue life of metal components. The process produces deep residual compressive stress into treated surfaces, typically five to ten times deeper than conventional metal shot peening. These deep compressive residual stresses inhibit the initiation and propagation of fatigue cracks. Laser peening has been particularly effective in increasing the resistance to fatigue crack propagation initiated from foreign object damage in titanium alloy fan and compressor blades of aircraft gas turbine engines. [1,2,3,4] However, the potential application of this process is much broader, encompassing automotive parts, orthopedic implants, tooling and dies, and others. Significant progress has been made to lower the cost and increase the throughput of the process, making it affordable for numerous applications. This paper reviews the status of laser peening technology, material property enhancements, and potential applications. KEYWORDS Laser shock peening, fatigue, life, residual stress, surface, enhancement HOW LASER PEENING WORKS Laser peening drives a high amplitude shock wave into a material surface using a high energy pulsed laser. The effect on the material being processed is achieved through the mechanical “cold working” effect produced by the shock wave, not a thermal effect from heating of the surface by the laser beam. The laser system is a high-energy, pulsed neodymium-glass laser system having a wavelength of 1.054 µm. The laser peening system produces very short laser pulses, selectable from 8 to 40 nanoseconds, with a pulse energy of up to 50 joules.
    [Show full text]
  • Effects of Laser and Shot Peening on Fatigue Life in Friction Stir Welds
    Effects of Different R ratios on Fatigue Crack Growth in Laser peened Friction Stir Welds Omar Hatamleh1,a, Lloyd Hackel2,b , Scott Forth3,c 1) Structures & Dynamics Branch, NASA-Johnson Space Center, Houston, Texas 77058 2) Metal Improvement Company, 7655 Longard Rd, Livermore, California 94551 3) Materials & Processes Branch, NASA-Johnson Space Center, Houston, Texas 77058 [email protected], [email protected], [email protected] Keywords: friction stir welding, laser peening, shot peening, fatigue crack growth Abstract. The influence of laser peening on the fatigue crack growth behavior of friction stir welded (FSW) Aluminum Alloy (AA) 7075-T7351 sheets was investigated. The surface modification resulting from the peening process on the fatigue crack growth of FSW was assessed for two different R ratios. The investigation indicated a significant decrease in fatigue crack growth rates resulting from using laser shock peening compared with unpeened, welded and unwelded specimens. The slower fatigue crack growth rate was attributed to the compressive residual stresses induced by the peening. 1. Introduction Friction stir welding (FSW) was invented by the Welding Institute in England in 1991 [1]. Since then, FSW has emerged as a promising solid state process with encouraging results, particularly when used on high strength aerospace aluminum alloys that are generally difficult to weld [2]. FSW transforms metals into a plastic state at a temperature below the melting temperature of the material, and then mechanically stirs the materials together, under pressure to produce high strength bonds. Residual stresses developed during welding [3,4] can have a significant effect on the service performance of welded material with respect to fatigue properties, and fatigue crack growth process.
    [Show full text]
  • Laser Peening Process and Its Impact on Materials Properties in Comparison with Shot Peening and Ultrasonic Impact Peening
    Materials 2014, 7, 7925-7974; doi:10.3390/ma7127925 OPEN ACCESS materials ISSN 1996-1944 www.mdpi.com/journal/materials Review Laser Peening Process and Its Impact on Materials Properties in Comparison with Shot Peening and Ultrasonic Impact Peening Abdullahi K. Gujba 1 and Mamoun Medraj 1,2,* 1 Department of Mechanical and Industrial Engineering, Concordia University, 1455 De Maisonneuve Blvd. W., Montreal, QC H3G 1M8, Canada; E-Mail: [email protected] 2 Department of Mechanical and Materials Engineering, Masdar Institute, Masdar City, P.O. Box 54224, Abu Dhabi, UAE * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +1-514-848-2424 (ext. 3146); Fax: +1-514-848-3175. External Editor: Douglas Ivey Received: 17 October 2014; in revised form: 18 November 2014 / Accepted: 27 November 2014 / Published: 10 December 2014 Abstract: The laser shock peening (LSP) process using a Q-switched pulsed laser beam for surface modification has been reviewed. The development of the LSP technique and its numerous advantages over the conventional shot peening (SP) such as better surface finish, higher depths of residual stress and uniform distribution of intensity were discussed. Similar comparison with ultrasonic impact peening (UIP)/ultrasonic shot peening (USP) was incorporated, when possible. The generation of shock waves, processing parameters, and characterization of LSP treated specimens were described. Special attention was given to the influence of LSP process parameters on residual stress profiles, material properties and structures. Based on the studies so far, more fundamental understanding is still needed when selecting optimized LSP processing parameters and substrate conditions.
    [Show full text]
  • Laser Peening Vs. Shot Peening: Engineering of Residual Stresses, Surface Roughness and Cold Working
    Laser Peening vs. Shot Peening: engineering of residual stresses, surface roughness and cold working 0. Higounenc1 1 Metal Improvement Company I Curtiss Wright Surface Technologies, Bayonne, France Abstract In Laser Peening (LP), compared to Shot Peening (SP), the magnitude of residual compressive stress at the surface is the same: about 60% of elastic limit; but the depth is much higher. In Low Cycle Fatigue (LCF) depth of residual compressive stress is beneficial because it does not only delay crack initiation, but also crack propagation. Depth of residual stress is also crit­ ical in Foreign Object Damage (FOO) and Crack Grow Rate (CGR) applications. Changes in surface roughness, as soon as cold work, are much more significant in shot SP compared to LP. Those changes can have a positive, or a negative influence depending on application and condition: HCF or LCF, deteriorating or non-deteriorating environment such as corrosion or FOO, fretting, surface contact fatigue. Thus, LP is complementary to SP in some specific applications such as LCF, FOO, CGR. The other advantage is the extremely high process control that allow more easily to take into ac­ count the credit of LP in the design .. Keywords: shot peening, laser peening, fatigue life, crack nucleation, crack propagation Introduction Laser Peening (LP) is a process in which an iintense beam of laser light (irradiance 2 to 1OGW/cm2) is directed on to a sacrificial ablating material placed on the surface of the com­ ponent to be treated. The light rapidly vaporizes a thin portion of the ablative layer, producing a plasma that is confined by the inertia of a thin laminar layer of water (-1 mm thick) flowing over the surface.
    [Show full text]
  • Laser Induced Shock Wave Studies of Para and Ferro Magnetic Materials
    cien al S ce Hamoudi et al., J Material Sci Eng 2017, 6:3 ri s te & a E M n DOI: 10.4172/2169-0022.1000349 f g o i n l e a e n r r i n u g o Journal of Material Sciences & Engineering J ISSN: 2169-0022 Research Article Article Open Access Laser Induced Shock Wave Studies of Para and Ferro Magnetic Materials Walid K Hamoudi, Dayah N Raouf and Narges Zamil* Applied Sciences Department, University of Technology, Baghdad, Iraq Abstract In the present work, laser induced shock wave on different materials was studied, the used materials is [Paramagnetic metal (Stainless steel 304) and Ferro magnetic metals (Iron)]; immersed in some media (air and water) to study the media effect on its properties. These materials are irradiated by using different laser intensities. Laser induced shock wave was achieved by employing Nd-YAG laser at wavelength 1064 nm. X-ray diffraction revealed shifting in diffracted angles of Fe toward higher angles due to phase transformation where in air transition from Austenite to Martensite while in water from Martensite to Martensite has smaller grain size because high generated temperature followed by quenched, the diffracted angle of S.S.304 metal shifted toward very little value due to twining effects where high stress and strain are produced. Keywords: Laser induced shock wave; Hardening; XRD of shocked materials in different media (air, water, and ethanol) was tested. and un-shocked metal The metals were classified into; Paramagnetic metal (S.S. 304), Ferromagnetic metals (Fe). Some of the used materials were thin plates Introduction (Iron, Stainless steel).
    [Show full text]