The Role of Additive Manufacturing in the Era of Industry 4.0

Revisiting fundamental welding concepts to improve additive manufacturing: From theory to practice

Residual Stress in Metal Additive Manufacturing

Assessing Industry 4.0 readiness in manufacturing: Evidence for the European Union

The directed energy deposition (DED) process can be employed to build net shape components or prototypes starting from powder or wires, through a layer-by-layer process. This process provides an opportunity to fabricate complex shaped and functionally graded parts that can be utilized in different engineering applications. DED uses a laser as a focused heat source to melt the in-situ delivered powder or wire-shaped raw materials. In the past years extensive studies on DED have shown that this process has great potential in order to be used for (i) rapid prototyping of metallic parts, (ii) fabrication of complex and customized parts, (iii) repairing/cladding valuable components which cannot be repaired by other traditional techniques. However, the industrial adoption of this process is still challenging owing to the lack of knowledge on the mechanical performances of the constructed components and also on the trustworthiness/durability of engineering parts produced by DED. This manuscript provides an overview of the additive manufacturing (AM) of titanium alloys and focuses in particular on the mechanical properties and microstructure of components fabricated by DED.

An Overview of Additive Manufacturing of Titanium Components by Directed Energy Deposition: Microstructure and Mechanical Properties

Wire Arc Additive Manufacturing (WAAM) is attracting significant attention in industry and academia due to its ability to capture the benefits of additive manufacturing for production of large components of medium geometric complexity. Uniquely, WAAM combines the use of wire and electric arc as a fusion source to build components in a layer-by-layer approach, both of which can offer significant cost savings compared to powder and alternative fusion sources, such as laser and electron beam, respectively. Meanwhile, a high deposition rate, key for producing such components, is provided, whilst also allowing significant material savings compared to conventional manufacturing processes. However, high quality production in a wide range of materials is limited by the elevated levels of heat input which causes a number of materials processing challenges in WAAM. The materials processing challenges are fully identified in this paper to include the development of high residual stresses, undesirable microstructures, and solute segregation and phase transformations at solidification. The thermal profile during the build poses another challenge leading to heterogeneous and anisotropic material properties. This paper outlines how the materials processing challenges may be addressed in WAAM by implementation of quality improving ancillary processes. The primary WAAM process selections and ancillary processes are classified by the authors and a comprehensive review of their application conducted. Strategies by which the ancillary processes can enhance the quality of WAAM parts are presented. The efficacy and suitability of these strategies for versatile and cost effective WAAM production are discussed and a future vision of WAAM process developments provided.

https://purehost.bath.ac.uk/ws/files/183236429/StrategiesAndProcessesForHighQualityWireArcAdditiveManufacturing_Manuscript.pdf

Invited review article: Strategies and processes for high quality wire arc additive manufacturing

By synergistically combining additive and subtractive processes within a single workstation, the relative merits of each process may be harnessed. This facilitates the manufacture of internal, overhanging and high aspect ratio features with desirable geometric accuracy and surface characteristics. The ability to work, measure and then rework material enables the reincarnation and repair of damaged, high-value components. These techniques present significant opportunities to improve material utilisation, part complexity and quality management in functional parts. The number of single platform workstations for hybrid additive and subtractive processes (WHASPs) is increasing. Many of these integrate additive directed energy deposition (DED) with subtractive CNC machining within a highly mobile multi-axis machine tool. Advanced numerical control (NC), and computer aided design (CAD), manufacture (CAM) and inspection (CAI) help to govern the process. This research reviews and critically discusses salient published literature relating to the development of WHASPs, and identifies future avenues for research and development. It reports on state-of-the-art WHASP systems, identifying key traits and research gaps. Finally, a future vision for WHASPs and other hybrid machine tools is presented based upon emerging trends and future opportunities within this research area.

/pdf/hybrid-additive-and-subtractive-machine-tools-research-and-9u0kvlu492.pdf

Hybrid additive and subtractive machine tools – Research and industrial developments

Since 2011, the manufacturing sector has been subject to a paradigm shift referred to as Industry 4.0, or the 4 Industrial Revolution. Industry 4.0 is concerned with cyber-physical systems for production engineering that enable the interconnected smart factories of the future. Its associated emerging technologies will bring along significant changes with respect to manufacturing processes and supply chains, allowing manufacturers to maintain their competitive edge in a rapidly changing globalized world. A recent study revealed that in 2016 only 8% of the UK manufacturers had a significant understanding of the term Industry 4.0, and that 56% had little or no understanding of it. However, 59% believed Industry 4.0 would have a big impact on the manufacturing sector. Most of the ongoing research on Industry 4.0 is concerned with the actual development of cyber-physical systems, cloud manufacturing, cybersecurity, and big data analytics. This study investigates the potential impact of Industry 4.0 on future unemployment, and the need for a highly responsive education system to develop the Industry 4.0 workforce of near tomorrow. At present, educational systems appear not to be adapting fast enough to respond to future labour demands imposed by Industry 4.0. If not addressed, this challenge may result in the required skills being undersupplied, thereby fuelling disparities between labour supply and demand, which consequently may cause unemployment levels to rise. This highlights the need to further investigate this situation and to identify and fulfil the educational requirements underlying future employment in a post Industry 4.0 era.

/pdf/industry-4-0-and-its-potential-impact-on-employment-54k59oog6x.pdf

Industry 4.0 and its Potential Impact on Employment Demographics in the UK

Guidelines when considering pre & post processing of large metal additive manufactured parts

https://purehost.bath.ac.uk/ws/files/155978093/A_generative_multi_agent_design_methodology_for_additively_manufactured_parts_inspired_by_termite_nest_building.pdf

Joseph Flynn

Papers

Invited review article: Strategies and processes for high quality wire arc additive manufacturing

Hybrid additive and subtractive machine tools – Research and industrial developments

Industry 4.0 and its Potential Impact on Employment Demographics in the UK

Guidelines when considering pre & post processing of large metal additive manufactured parts

A generative multi-agent design methodology for additively manufactured parts inspired by termite nest building