Download or read book The Effect of Laser Welding Process Parameters on the Mechanical and Microstructural Properties of V 4CR 4TI Structural Materials written by and published by . This book was released on 1999 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: V-Cr-Ti alloys are among the leading candidate materials for the frost wall and other structural materials applications in fusion power reactors because of several important advantages including inherently low irradiation-induced activity, good mechanical properties, good compatibility with lithium, high thermal conductivity and good resistance to irradiation-induced swelling and damage [1]. However, weldability of these alloys in general must be demonstrated, and laser welding, specifically, must be developed. Laser welding is considered to be an attractive process for construction of a reactor due to its high penetrating power and potential flexibility. This paper reports on a systematic study which was conducted to examine the use of a pulsed Nd:YAG laser to weld sheet materials of V-Cr-Ti alloys and to characterize the microstructural and mechanical properties of the resulting joints. Deep penetration and defect-free welds were achieved under an optimal combination of laser parameters including focal length of lens, pulse energy, pulse repetition rate, beam travel speed, and shielding gas arrangement. The key for defect-free welds was found to be the stabilization of the keyhole and providing an escape path for the gas trapped in the weld. An innovative method was developed to obtain deep penetration and oxygen contamination free welds. Oxygen and nitrogen uptake were reduced to levels only a few ppm higher than the base metal by design and development of an environmental control box. The effort directed at developing an acceptable postwelding heat treatment showed that five passes of a diffuse laser beam over the welded region softened the weld material, especially in the root region of the weld.
Download or read book Next Generation Materials and Processing Technologies written by Swarup Bag and published by Springer Nature. This book was released on 2021-06-13 with total page 581 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the select proceedings of Conference on Research and Developments in Material Processing, Modelling and Characterization (RDMPMC 2020). It highlights the new technologies developed in the generation of rational materials for various applications with tailored properties. It covers fundamental research in emerging materials which includes biomaterials, composites, ceramics, functionally graded materials, energy materials, thin film materials, nanomaterials, nuclear materials, intermetallic, high strength materials, structural materials, super alloys, shape memory alloys and thermally enhanced materials. It includes the numerical modeling and computer simulation to investigate the properties and structure of materials. Few of the most relevant manufacturing techniques highlighted in this book are welding, coating, additive manufacturing, laser-based manufacturing, advanced machining processes, casting, forming and micro and nanoscale manufacturing processes. Given its contents, this book is beneficial to students, researchers and industry professionals.
Download or read book Mechanical Properties and Microstructural Characteristics of Laser and Electron beam Welds in V 4Cr 4Ti written by and published by . This book was released on 1998 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanical properties and microstructural characteristics of laser and electron-beam welds of a 500-kg heat of V4Cr4Ti were investigated in as-welded condition and after postwelding heat treatment by impact testing, microhardness measurement, optical microscopy, X-ray diffraction, and transmission electron microscopy (TEM). Ductile-brittle transition temperatures of the laser and electron-beam welds were significantly higher than that of the base metal. However, excellent impact properties could be restored in both types of welds by postwelding annealing at 1000 C for 1 h in vacuum. Analysis by TEM revealed that annealed weld zones were characterized by extensive networks of fine V(C, O, N) precipitates, which clean away O, C, and N interstitial from the grain matrices. This process is accompanied by simultaneous annealing-out of the dense dislocations present in the weld zone. This finding could be useful in identifying an optimal welding procedure by controlling and adjusting the cooling rate of the weld zone by an innovative method to maximize the precipitation of V(C, O, N).
Download or read book Advanced Joining Technologies written by Manjaiah M and published by CRC Press. This book was released on 2024-03-13 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers advances in fusion and solid-state welding processes including basics, welding metallurgy, defect formation, and the effect of process parameters on mechanical properties. Details of the microstructural and mechanical behaviors of weldments are included. This book covers challenges encountered during dissimilar welding of metal by fusion and solid-state welding processes, including remedial solutions and hybrid processes to counter the same. Numerical and statistical simulation approaches used in the welding process for parameter optimization and material flow studies are described as well. Features: Provides details related to the microstructural and mechanical behaviors of welded joints developed by different welding processes. Covers recent research content, metallurgical analysis, and simulation aspects. Discusses the joining of plastics and ceramics. Includes a dedicated chapter on machine learning and digital twin in welding. Explores difficulties associated with the joining of dissimilar metals and alloys. This book is aimed at researchers and graduate students in material joining and characterization and welding.
Download or read book Microstructural Characteristics and Mechanism of Toughness Improvement of Laser and Electron beam Welds of V 4Cr 4Ti Following Postwelding Heat treatment written by and published by . This book was released on 1996 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors are conducting a program to develop an optimal laser welding procedure for large-scale fusion-reactor structural components to be fabricated from vanadium-base alloys. Microstructural characteristics were investigated by optical microscopy, X-ray diffraction, transmission electron microscopy, and chemical analysis to provide an understanding of the mechanism of the drastic improvement of impact toughness of laser and electron-beam (EB) welds of V-4Cr-4Ti following postwelding annealing at 1000°C. Transmission electron microscopy (TEM) revealed that annealed weld zones were characterized by extensive networks of fine V(C, O, N) precipitates, which appear to clean away O, C, and N from grain matrices. This process is accompanied by simultaneous annealing-out of the dense dislocations present in the weld fusion zone. It seems possible to produce high-quality welds under practical conditions by controlling and adjusting the cooling rate of the weld zone by some innovative method to maximize the precipitation of V(C, O, N).
Download or read book Laser Welding written by João Pedro Oliveira and published by MDPI. This book was released on 2020-05-13 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser welding is a high-energy process used in a wide range of advanced materials to obtain micro- to macro-sized joints in both similar and dissimilar combinations. Moreover, this technique is widely used in several industries, such as automotive, aerospace, and medical industries, as well as in electrical devices. Although laser welding has been used for several decades, significant and exciting innovations often arise from both the process and/or advanced materials side.
Download or read book Science Characterization and Technology of Joining and Welding written by Meysam Haghshenas and published by MDPI. This book was released on 2020-05-22 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the Guest Editor of this Special Issue entitled "Science, Characterization, and Technology of Joining and Welding" of Metals, I am pleased to have this book published by MDPI. Joining, including welding, soldering, brazing, and assembly, is an essential requirement in manufacturing processes and is classified as a secondary manufacturing process. This Special Issue of Metals includes technical and review papers on, but not limited to, different aspects of joining and welding, including welding technologies (i.e., fusion-based welding and solid-state welding), characterization, metallurgy and materials science, quality control, and design and numerical simulation. This Special Issue also includes the joining of different materials, including metal and non-metals (polymers and composites), including 17 peer-reviewed papers from several researchers all around the globe (China, Germany, Brazil, South Koria, Slovakia, USA, Taiwan, Canada, and India). As of this date (April 2020), the papers in this Special Issue have been cited 47 times by other researchers, which I think is an eminent number and shows the high quality of the published papers in this Issue. This Special Issue includes a large diversity of various subjects in the field of joining: laser welding, friction stir welding, diffusion bonding, multipass welding, rotary friction-welding, friction bit joining, adhesive bonding, weldbonding, simulation and experimentation, metal/FRP joints, welding simulation, plasma–TIG coupled arc welding, liquation cracking, soldering, resin bonding, microstructural characteristics, brazing, and friction stir butt and scarf welding. I would like to sincerely thank all the researchers who contributed to this Special Issue for their high-quality research. I also would like to acknowledge Mr. Toliver Guo, Senior Assistant Editor at MDPI, who continuously and tirelessly contributed toward this Special Issue by assisting me with inviting the authors and the follow ups. I think this Special Issue will enhance our knowledge and understanding in the field of joining and assembly. I would like to dedicate this book to my wife, Mehrnoosh, for her continued support and encouragement.
Download or read book The Effect of Direct Laser Deposition Process Parameters on Microstructure and Mechanical Properties of Ti 6Al 2Sn 4Zr 6Mo written by Emily S. Davison and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impact Properties and Hardening Behavior of Laser and Electron beam Welds of V 4Cr 4Ti written by and published by . This book was released on 1996 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors are conducting a program to develop an optimal laser welding procedure that can be applied to large-scale fusion-reactor structural components to be fabricated from vanadium-base alloys. Results of initial investigation of mechanical properties and hardening behavior of laser and electron-beam (EB) welds of the production-scale heat of V-4Cr-4Ti (500-kg Heat 832665) in as-welded and postwelding heat-treated (PWHT) conditions are presented in this paper. The laser weld was produced in air using a 6-kW continuous CO2 laser at a welding speed of H"5 mm/s. Microhardness of the laser welds was somewhat higher than that of the base metal, which was annealed at a nominal temperature of H"050°C for 2 h in the factory. In spite of the moderate hardening, ductile-brittle transition temperatures (DBTTs) of the initial laser (H"0°C) and EB (H"0°C) welds were significantly higher than that of the base metal (H"170°C). However, excellent impact properties, with DBTT
Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Welding of Duplex Stainless Steels written by Thoria Sharef and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The duplex stainless steels have been developed to provide a combination of tensile properties and resistance to pitting and stress corrosion cracking in comparison with the 300--series austenitic stainless steels. The optimum properties of duplex stainless steels are achieved when nearly equal proportions of aus-tenite and ferrite are present in the microstructure. Control of the ferrite/austenite balance in welds is not as straightforward as in the base metals since it depends on different welding parameters as well as type of welding process. This book is concerned with laser beam welding and its effect on size and microstructure of fusion zone then, on mechanical and corrosion properties of welded joints of the widely used 2205 duplex stainless steel plates. Results of laser welding process have been compared with that of tungsten inert gas (TIG) welding process. The results achieved in this investigation disclosed that laser welding parameters including laser power, welding speed, defocusing distance and type of shielding gas combinations play an important role in obtaining laser welded joint with acceptable fusion zone size and weld profile.
Download or read book Effects of the Laser Beam Powder Welding Process on the Hardenability of Superalloy IN 738LC Deposition Welds written by José Humberto García Buitrago and published by . This book was released on 1995 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts Index written by and published by . This book was released on 1995 with total page 1390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Materials Science and Welding Technologies written by Nicușor Alin Sîrbu and published by Trans Tech Publications Ltd. This book was released on 2023-08-18 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Special topic volume with invited peer-reviewed papers only
Download or read book Laser Cladding of Metals written by Pasquale Cavaliere and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser cladding is an additive manufacturing technology capable of producing coatings due to the surface fusion of metals. The selected powder is fed into a focused laser beam to be melted and deposited as coating. This allows to apply material in a selected way onto those required sections of complex components. The process main properties are the production of a perfect metallurgically bonded and fully dense coatings; the minimal heat affected zone and low dilution between the substrate and filler material resulting in functional coatings that perform at reduced thickness, so fewer layers are applied; fine, homogeneous microstructure resulting from the rapid solidification rate that promotes wear resistance of carbide coatings; near net-shape weld build-up requires little finishing effort; extended weldability of sensitive materials like carbon-rich steels or nickel-based superalloys that are difficult or even impossible to weld using conventional welding processes; post-weld heat treatment is often eliminated as the small heat affected zone minimizes component stress; excellent process stability and reproducibility because it is numerical controlled welding process. The typical applications are the dimensional restoration; the wear and corrosion protection; additive manufacturing. The wide range of materials that can be deposited and its suitability for treating small areas make laser cladding particularly appropriate to tailor surface properties to local service requirements and it opens up a new perspective for surface engineered materials. The main key aspect to be scientifically and technologically explored are the type of laser; the powders properties; the processing parameters; the consequent microstructural and mechanical properties of the processed material; the capability of fabrication of prototypes to rapid tooling and rapid manufacturing. Distills critical concepts, methods, and applications from leading full-length chapters, along with the authors's own deep understanding of the material taught, into a concise yet rigorous graduate and advanced undergraduate text; Reinforces concepts covered with detailed solutions to illuminating and challenging industrial applications; Discusses current and future applications of laser cladding in additive manufacturing.
Download or read book High Strength Impact Welding of Structural and Functional Materials written by Jianxiong Li (Ph. D. in materials science) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissimilar material welding has grown in popularity in the lightweight design of biomedical, automotive, and aerospace products. However, welding of two or more different materials presents difficulties due to their notable mismatch in chemical, physical and mechanical properties. Some traditional joining methods are undesirable due to the formation of intermetallic compounds and thermally induced defects. These defects make the dissimilar welds unable to reliably serve in actual applications. Vaporizing Foil Actuator Welding (VFAW), an impact welding method, can minimize the abovementioned defects and join various dissimilar metals in solid state with reliable properties. This dissertation focuses on developing VFAW to join three metal pairs including Ti/stainless steel (SS), NiTi/SS, and NiTi/brass alloy. The process, microstructure, and properties of these dissimilar impact welds were explored through advanced techniques and compared with traditional welding methods. This work also introduces a new additive manufacturing method based on impact welding, called Ballistic Additive Manufacturing (BAM). The potential applications and overall long term vision of BAM were demonstrated. The results show that VFAW was effective in joining Ti and stainless steel. Ti/SS impact welds have reproducible macro- and micro-structure and show spatial heterogeneities at large and small length scales. Simulation shows that strength and failure modes are not affected adversely by the size of the central unbonded zone. Since mufflers in automobile could encounter thermal exposure ranging from 300 to 800 °C, a Nb interlayer was introduced to improve the thermal resistance. Both types of bonds give base metal failure in lap shear tests in as-welded condition. Guidelines for the production, properties and applications of these classes of welds are provided. High strength and fatigue resistant impact welds were produced between a NiTi shape memory alloy and dissimilar metals including SS and brass alloy for the first time. Good retention of the superelastic property and strength in the VFAW nitinol welds could be ascribed to the lack of heat affected zone formation, the solid-state bonding interfaces and the grain refinement near the interfaces. The unparalleled performance of these high-strength solid-state similar and dissimilar welds is a solution to the increasing demands of applications in various industrial fields including the medical, automotive, aerospace and electronic sectors. BAM is a new class of additive manufacturing processes achieved by the sequential solid-state impact welding of elements. In this work, BAM was found to be a promising technology that can be used to carry out crack repair and groove filling by either combined shearing and welding method or directly welding of thin flyer sheets to a pre-machined part. The overall long-term vision for BAM is to automate the manufacturing system so that quick and efficient repairment of damaged parts, impact fill welding of dissimilar metals, and fabrication of arbitrary shapes with graded compositions can be achieved at low process energies.
Download or read book Microstructure and Mechanical Properties of Laser Welds in Structural Steels written by Im Norris Bmet and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
