Hot Work Tool Steel In Laser Powder Bed Fusion From Parameter Optimization To Quality Monitoring In Industrial Application

This dissertation thesis focuses on applying the powder bed fusion with laser beam (PBF-LB) technology on hot work steel. It aims at achieving comparable properties with the products from the traditional manufacturing route. Using the reference powder H13, the influence of various factors, i.e., laser settings (such as laser power and scan speed) and machine settings (such as preheating) on the melting pool morphology and printing defects, is intensively investigated to check the feasibility of printing H13 components through PBF-LB technology and finally optimize the fabrication parameters for high-quality printing in lab-scale size. Furthermore, the consecutive research on the impact of the post-treatment, machine sensitivity, and powder condition provides a basis for scaling up the process and offers industrially usable products with adequate properties. Furthermore, after assessing the defects during the investigation, the classification of the defects deepens the understanding of the material-laser interaction. The mechanism for stress-lead cracks can guide the development of new types of material applied to the PBF-LB process, especially carbon-bearing steel. Finally, based on the mechanism of defect generation, the principle of the real-time defect-based monitoring system is proposed. After recognizing defects and assembling discrete points, the digital twin is established from various monitoring signals, which can be applied for on-time quality assurance without destructive testing.

Additive manufacturing (AM) is the process in which a three-dimensional object is built by adding subsequent layers of materials. AM enables novel material compositions and shapes, often without the need for specialized tooling. This technology has the potential to revolutionize how mechanical parts are created, tested, and certified. However, successful real-time AM design requires the integration of complex systems and often necessitates expertise across domains. Simulation-based design approaches, such as those applied in engineering product design and material design, have the potential to improve AM predictive modeling capabilities, particularly when combined with existing knowledge of the underlying mechanics. These predictive models have the potential to reduce the cost of and time for concept-to-final-product development and can be used to supplement experimental tests. The National Academies convened a workshop on October 24-26, 2018 to discuss the frontiers of mechanistic data-driven modeling for AM of metals. Topics of discussion included measuring and modeling process monitoring and control, developing models to represent microstructure evolution, alloy design, and part suitability, modeling phases of process and machine design, and accelerating product and process qualification and certification. These topics then led to the assessment of short-, immediate-, and long-term challenges in AM. This publication summarizes the presentations and discussions from the workshop.

Additive Manufacturing (AM), more popularly known as 3D printing, is transforming the industry. AM of metal components with virtually no geometric limitations has enabled new product design options and opportunities, increased product performance, shorter cycle time in part production, total cost reduction, shortened lead time, improved material efficiency, more sustainable products and processes, full circularity in the economy, and new revenue streams. This Special Issue of Metals gives an up-to-date account of the state of the art in AM.

This book entitled “Laser Additive Manufacturing of High-Performance Materials” covers the specific aspects of laser additive manufacturing of high-performance new materials components based on an unconventional materials incremental manufacturing philosophy, in terms of materials design and preparation, process control and optimization and theories of physical and chemical metallurgy. This book describes the capabilities and characteristics of the development of new metallic materials components by laser additive manufacturing process, including nanostructured materials, in situ composite materials, particle reinforced metal matrix composites, etc. The topics presented in this book, similar as laser additive manufacturing technology itself, show a significant interdisciplinary feature, integrating laser technology, materials science, metallurgical engineering and mechanical engineering. This is a book for researchers, students, practicing engineers and manufacturing industry professionals interested in laser additive manufacturing and laser materials processing. Dongdong Gu is a Professor at College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics (NUAA), PR China.

This book covers in detail the various aspects of joining materials to form parts. A conceptual overview of rapid prototyping and layered manufacturing is given, beginning with the fundamentals so that readers can get up to speed quickly. Unusual and emerging applications such as micro-scale manufacturing, medical applications, aerospace, and rapid manufacturing are also discussed. This book provides a comprehensive overview of rapid prototyping technologies as well as support technologies such as software systems, vacuum casting, investment casting, plating, infiltration and other systems. This book also: Reflects recent developments and trends and adheres to the ASTM, SI, and other standards Includes chapters on automotive technology, aerospace technology and low-cost AM technologies Provides a broad range of technical questions to ensure comprehensive understanding of the concepts covered

New chapters on bending and cleaning reflect the changes in the field since the last edition, completing the range of practical knowledge about the processes possible with lasers already familiar to users of this well-known text. Professor Steen's lively presentation is supported by a number of original cartoons by Patrick Wright and Noel Ford, which will bring a smile to your face and ease the learning process. From the reviews: "...well organized, and the text is very practical...The engineering community will find this book informative and useful." (OPTICS AND PHOTONICS NEWS, July/August 2005)

METAL ADDITIVE MANUFACTURING A comprehensive review of additive manufacturing processes for metallic structures Additive Manufacturing (AM)—also commonly referred to as 3D printing—builds three-dimensional objects by adding materials layer by layer. Recent years have seen unprecedented investment in additive manufacturing research and development by governments and corporations worldwide. This technology has the potential to replace many conventional manufacturing processes, enable the development of new industry practices, and transform the entire manufacturing enterprise. Metal Additive Manufacturing provides an up-to-date review of all essential physics of metal additive manufacturing techniques with emphasis on both laser-based and non-laser-based additive manufacturing processes. This comprehensive volume covers fundamental processes and equipment, governing physics and modelling, design and topology optimization, and more. The text adresses introductory, intermediate, and advanced topics ranging from basic additive manufacturing process classification to practical and material design aspects of additive manufacturability. Written by a panel of expert authors in the field, this authoritative resource: Provides a thorough analysis of AM processes and their theoretical foundations Explains the classification, advantages, and applications of AM processes Describes the equipment required for different AM processes for metallic structures, including laser technologies, positioning devices, feeder and spreader mechanisms, and CAD software Discusses the opportunities, challenges, and current and emerging trends within the field Covers practical considerations, including design for AM, safety, quality assurance, automation, and real-time control of AM processes Includes illustrative cases studies and numerous figures and tables Featuring material drawn from the lead author’s research and professional experience on laser additive manufacturing, Metal Additive Manufacturing is an important source for manufacturing professionals, research and development engineers in the additive industry, and students and researchers involved in mechanical, mechatronics, automatic control, and materials engineering and science.

Titanium Powder Metallurgy contains the most comprehensive and authoritative information for, and understanding of, all key issues of titanium powder metallurgy (Ti PM). It summarizes the past, reviews the present and discusses the future of the science and technology of Ti PM while providing the world titanium community with a unique and comprehensive book covering all important aspects of titanium powder metallurgy, including powder production, powder processing, green shape formation, consolidation, property evaluation, current industrial applications and future developments. It documents the fundamental understanding and technological developments achieved since 1937 and demonstrates why powder metallurgy now offers a cost-effective approach to the near net or net shape fabrication of titanium, titanium alloys and titanium metal matrix composites for a wide variety of industrial applications. Provides a comprehensive and in-depth treatment of the science, technology and industrial practice of titanium powder metallurgy Each chapter is delivered by the most knowledgeable expert on the topic, half from industry and half from academia, including several pioneers in the field, representing our current knowledge base of Ti PM. Includes a critical review of the current key fundamental and technical issues of Ti PM. Fills a critical knowledge gap in powder metal science and engineering and in the manufacture of titanium metal and alloys