The combustion of fossil fuels for energy generation has contributed considerably to the effects of climate change. In order to reduce fossil fuel consumption, designers are increasingly seeking to reduce the energy consumption of products over their life cycle. To achieve a significant reduction in energy consumption, it is essential that energy considerations are incorporated within the design phase of a product, since the majority a product's environmental impact is determined during this phase. This work proposes a new ‘Design for Energy Minimization’ (DfEM) approach, which is intended to provide increased transparency with respect to the energy consumed during manufacture in order to help inform design decisions. An energy simulation model based on this approach is then presented to aid designers during the design phase. The application of this novel design tool is demonstrated in two cases: That of a simple product (designed by a single Original Equipment Manufacturer (OEM) through a centralized approach); and a complex product (designed by a number of designers within a supply chain using a distributed approach). The subsequent benefits to energy minimization are then discussed and conclusions drawn

NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Materials Processing Technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Materials Processing Technology, VOL 220, 2015. DOI: 10.1016/j.jmatprotec.2015.01.023This work investigates the use of holographic optical elements (HOE's) to control the applied heat profile and thermal absorption of a wire used for laser cladding. The two thermal distributions compared were a circular beam with a Gaussian heat profile (Gaussian beam) and a square beam with a flat profile (pedestal beam). Heat absorption calculations between these were carried out to show the potential differences in absorption, with empirical results created to show how the differences in absorption affect the cladding properties. Micrographs of the clad cross-sections were created using optical microscopy and were analysed with respect to wetting angle and clad dilution. These results were compared to an alternative method of applying an even beam profile; enlarging the Gaussian beam relative to the wire diameter. The results showed that the use of a HOE to create a more even beam profile gave superior wetting behaviour and less dilution

Laser cladding is a well-established technique, with the majority of prior numerical modelling work focused on delivery and melt pool behaviour of powder-based processes. This research presents new investigations into optimised laser beam shaping for the unique characteristics of wire-based processes, where direct substrate heating, as well as heat transfer between the wire and substrate, is important. The value of this subject is the improved deposition rates and dense metallic structures that can be achieved by wire-based deposition processes compared to powder-based material delivery. The within-wire temperature distribution (AISI 316 stainless steel), the heat transfer and direct heating of the substrate (mild steel) are modelled via heat transfer simulations, with three laser beam irradiance distributions. This analysis identified the removal of localised high-temperature regions typically associated to standard Gaussian distributions, and the improved substrate heating that a uniform square beam profile can provide. Experiments using pre-placed wire and a 1.2 kW CO₂ laser were analysed using cross-sectional optical microscopy to provide model validation and evidence of improved wire-substrate wetting, while maintaining favourable austenitic metallurgy in the clad material. A key finding of this work is a reduction, from 480 to 190 W/mm², in the required irradiance for effective melt pool formation when changing from a Gaussian distribution to a uniform square distribution. This also provided a 50% reduction in total energy. The potential improvements to energy efficiency, cost reductions and sustainability improvements are recognised and discussed.

In an increasingly technological world, energy efficiency in manufacturing is of great importance. While large manufacturing corporations have the resources to commission energy studies with minimal impact on operations, this is not true for small and medium enterprises (SME’s). These businesses will commonly only have a small number of laser processing cells; thus, to carry out an energy study can be extremely disruptive to normal operations. Since rising global energy costs also have the largest impact on small businesses who lack the benefit of economies of scale, they are simultaneously the most in need of improvements to energy efficiency, while also facing the strongest practical barriers to implementing them. In this study, a laser processing energy analysis methodology was designed to run simultaneously with normal operation and applied to a laser shim-cutting cell in a UK-based SME. This paper demonstrates the methodology for identifying operating states in a production environment and Specific Energy Consumption and Scope 2 CO₂ emissions results are analysed. The Processing state itself was the most impactful on overall energy performance, at 55% for single sheets of material, increasing to 71% when batch processing. Generating idealised data in this production environment is challenging with restrictions to isolating variables, these “real-world” limitations for conducting system energy analysis simultaneously with live production are also discussed to present recommendations for further analysis.