Laser Shocking Nano Crystallization And High Temperature Modification Technology

The aim of this book is to present foundational research on the nano-crystallization, high-temperature modification, micro-structure evolution and plastic deformation induced by laser shock processing. In this regard, the focus is on heat-resistant steel, aluminum alloy, Ti alloys and Ni-based alloys, offering valuable scientific insights into the industrial applications of laser shock processing (LSP) technology. The book addresses various topics, i.e., the formation mechanism and productivity improvement of nano-crystalline diamond by laser processing, the surface integrity and fatigue lives of heat-resistant steels, Ti alloys and Ni-based alloys after LSP with different processing parameters, tensile properties and fractural morphology after LSP at different temperatures, strain-rates and grain refinement mechanisms based on the micro-structure evolution. Moreover, the effect of heating temperature and exposure time on stress thermal relaxation and the influence of compressive stress on the stress intensity factor of hole-edge cracks by high strain rate laser shock processing are also analyzed. A new type of statistical data model to describe the fatigue cracking growth with limited data is proposed based on the consideration of the effects of fracture growth on the reliability and confidence level. This book is intended for researchers, engineers and postgraduates in the fields of nanotechnology and micro-engineering who are interested in the partial or overall strengthening of materials, especially those with a focus on surface integrity and fatigue life.

This book provides a comprehensive overview of the latest advances in laser techniques for micro-nano-manufacturing and an in-depth analysis of applications, such as 3D printing and nanojoining. Lasers have gained increasing significance as a precise tool for advanced manufacturing. Written by world leading scientists, the first part of the book presents the fundamentals of laser interaction with materials at the micro- and nanoscale, including multiphoton excitation and nonthermal melting, and allows readers to better understand advanced processing. In the second part, the authors focus on various advanced fabrications, such as laser peening, surface nanoengineering, and plasmonic heating. Finally, case studies are devoted to special applications, such as 3D printing, microfluidics devices, energy devices, and plasmonic and photonic waveguides. This book integrates both theoretical and experimental analysis. The combination of tutorial chapters and concentrated case studies will be critically attractive to undergraduate and graduate students, researchers, and engineers in the relevant fields. Readers will grasp the full picture of the application of laser for micro-nanomanufacturing and 3D printing.

This thematic issue on advanced simulation tools applied to materials development and design predictions gathers selected extended papers related to power generation systems, presented at the XIX International Colloquium on Mechanical Fatigue of Metals (ICMFM XIX), organized at University of Porto, Portugal, in 2018. In this issue, the limits of the current generation of materials are explored, which are continuously being reached according to the frontier of hostile environments, whether in the aerospace, nuclear, or petrochemistry industry, or in the design of gas turbines where efficiency of energy production and transformation demands increased temperatures and pressures. Thus, advanced methods and applications for theoretical, numerical, and experimental contributions that address these issues on failure mechanism modeling and simulation of materials are covered. As the Guest Editors, we would like to thank all the authors who submitted papers to this Special Issue. All the papers published were peer-reviewed by experts in the field whose comments helped to improve the quality of the edition. We also would like to thank the Editorial Board of Materials for their assistance in managing this Special Issue.

Laser shock processing (LSP) is a new and promising surface treatment technique for improving the fatigue durability, corrosion, wear resistance and other mechanical properties of metals and alloys. During LSP, the generated shock wave can introduce a deep compressive residual stress into the material, due to its high-pressure (GPa-TPa), ultra-fast (several tens nanoseconds), ultra-high strain-rate and high-energy. The overall properties and behavior of metal materials subjected to LSP were significantly improved because a refined surface layer was successfully obtained. Nevertheless, up to now, a clear scenery between micro-structure and macro-property of the refined surface layer, especially formation of sub-micrometer grains from coarse grains during severe plastic deformation, is still pending. Therefore, the basic studies of the underlying mechanism for grain refinement by ultra-high strain-rate presented in this book becomes more and more crucial.

Severe plastic deformation (SPD) is a very attractive research field for metallic materials because it provides new possibilities for manufacturing nanostructured materials in large quantities and allows microstructural design on different hierarchical levels. The papers included in this issue address the following topics: novel SPD processes as well as recent advancements in established processing methods, microstructure evolution and grain refinement in single- and multi-phase alloys as well as composites, strategies to enhance the microstructure stability at elevated temperatures, mechanically driven phase transformations, surface nanostructuring, gradient and multilayered materials, and mechanical and physical properties of SPD-processed materials.

Nanomaterials contain some unique properties due to their nanometric size and surface functionalization. Nanomaterial functionalization also affects their compatibility to biocompatibility and toxicity behaviors. environment and living organism. This makes functionalized nanomaterials a material with huge scope and few challenges. This book provides detailed information about the nanomaterial functionalization and their application. Recent advancements, challenges and opportunities in the preparation and applications of functionalized nanomaterials are also highlighted. This book can serve as a reference book for scientific investigators, doctoral and post-doctoral scholars; undergrad and grad. This book is very useful for multidisciplinary researchers, industry personnel’s, journalists, and policy makers. Features: Covers all aspects of Nanomaterial functionalization and its applications Describes and methods of functionalized nanomaterials synthesis for different applications Discusses the challenges, recent findings, and cutting-edge global research trends on functionalization of nanomaterials and its applications It discusses the regulatory frameworks for the safe use of functionalized nanomaterials. It contains contributions from international experts from multiple disciplines.

New, significant scientific discoveries in laser and photonic technologies, systems perspectives, and integrated design approaches can improve even further the impact in critical areas of challenge. Yet this knowledge is dispersed across several disciplines and research arenas. Laser and Photonic Systems: Design and Integration brings together a mu

Ultrasonic Nano-Crystal Surface Modification (UNSM) is a relatively new material processing technology to enhance the operating service lives, or fatigue life, of engineering components. There is an increasing interest in extending this technology to metal parts such as aircraft engine turbine blades, compressor blades and medical implants such as spinal rods. In this process a ball made with tungsten carbide generates 20 - 40 KHz strikes of a few hundred Newton on the specimen surface. It works as a cold forging process; however the small ball that works itself across the specimen surface has a dynamic load added to the normal static load. The total striking force, feed, ball radius, amplitude of dynamic load and speed can vary to yield different results. UNSM induces severe plastic deformation and deep compressive residual stresses to increase surface hardness, improve surface roughness, and introduce nano-crystallization near the specimen surface. Currently there is no systematic approach to predict the material response under UNSM. Therefore the objective of this thesis is to develop a process model for predicting the material response as a result of the UNSM process. Before developing the model, experimental data is extracted from two UNSM treated coupons, one of Ti-6Al-4V and the other IN718 SPF. First a MATLAB code is developed to define the displacement history of the carbide ball on the surface of the specimen during the UNSM process. For titanium alloy (Ti-6Al-4V) a temperature, pressure, and rate dependent constitutive material model for is established to account for the high strain rates associated with UNSM. A semi-implicit forward tangent modulus algorithm is developed to implement the material and damage model, and this is linked with the FEM software LS-DYNA through a user-defined material subroutine. We use the Johnson Cook material model already within the LS-DYNA software to simulate IN718 SPF. The residual stress obtained from the simulation is compared and verified with experimental results. To further understand the UNSM process, the residual stress results are compared with Laser Shock Peening (LSP) to note the differences.

A selection of papers that examine various aspects of high-power lasers in manufacturing.