Towards criteria for sustainable process selection: On the modelling of pure subtractive versus additive/subtractive integrated manufacturing approaches

Additive Manufacturing (AM) processes can be counted among the disruptive technologies that are capable of transforming conventional manufacturing routes. The ability to create complex geometries, the reduction in material scraps during manufacturing, and the light-weighting due to the think-additive redesign of the components represent the main points of strength of AM. However, for some applications (such as the production of metal components for the automotive and aerospace industries), the surface finishing and dimensional/geometrical part tolerancing that can be achieved via AM processes might not be adequate to satisfy the imposed product specifications, and finish machining operations are often required. A machining approach and an integrated production route, based on an additive manufacturing process plus finish machining, have been compared in this paper. The primary energy demand and the CO2 emissions have been modelled for all the life cycle stages within a sustainable development context. The main result of the research work is a criterion for the selection of the most environmentally friendly manufacturing approach, while varying the productive scenario (i.e., the masses of the process scraps, the machined chips, and the support structures). The application of such a tool to the production of metal components made of either Ti-6Al-4V or stainless steel is discussed.

[1]  Wim Dewulf,et al.  Methodology for systematic analysis and improvement of manufacturing unit process life cycle inventory (UPLCI) CO2PE! initiative (cooperative effort on process emissions in manufacturing). Part 2: case studies , 2012, The International Journal of Life Cycle Assessment.

[2]  Iain Todd,et al.  XCT analysis of the influence of melt strategies on defect population in Ti?6Al?4V components manufactured by Selective Electron Beam Melting , 2015 .

[3]  R. Hague,et al.  Shape Complexity and Process Energy Consumption in Electron Beam Melting: A Case of Something for Nothing in Additive Manufacturing? , 2017 .

[4]  Mohammed A. Omar,et al.  Life cycle assessment-based selection for a sustainable lightweight body-in-white design , 2012 .

[5]  O. Edenhofer,et al.  Climate change 2014 : mitigation of climate change , 2014 .

[6]  Eric Coatanéa,et al.  Comparative environmental impacts of additive and subtractive manufacturing technologies , 2016 .

[7]  Michael F. Ashby,et al.  Materials and the Environment: Eco-informed Material Choice , 2009 .

[8]  Giuseppe Ingarao,et al.  On the Impact of Recycling Strategies on Energy Demand and CO2 Emissions When Manufacturing Al-based Components☆ , 2016 .

[9]  Sung-Hoon Ahn,et al.  A comparison of energy consumption in bulk forming, subtractive, and additive processes: Review and case study , 2014 .

[10]  T. Mower,et al.  Mechanical behavior of additive manufactured, powder-bed laser-fused materials , 2016 .

[11]  J. K. Watson,et al.  A decision-support model for selecting additive manufacturing versus subtractive manufacturing based on energy consumption. , 2018, Journal of cleaner production.

[12]  Jeremy Faludi,et al.  Comparing Environmental Impacts of Additive Manufacturing vs. Traditional Machining via Life-Cycle Assessment , 2015 .

[13]  Vojislav Petrovic,et al.  Powder recyclability in electron beam melting for aeronautical use , 2015 .

[14]  Steven J. Skerlos,et al.  Environmental aspects of laser-based and conventional tool and die manufacturing , 2007 .

[15]  Sami Kara,et al.  Towards Energy and Resource Efficient Manufacturing: A Processes and Systems Approach , 2012 .

[16]  Robert L. Bowerman,et al.  Introduction to the Additive Manufacturing Powder Metallurgy Supply Chain , 2015 .

[17]  Ryan B. Wicker,et al.  Microstructures and mechanical properties of electron beam-rapid manufactured Ti–6Al–4V biomedical prototypes compared to wrought Ti–6Al–4V , 2009 .

[18]  Sujit Das,et al.  Energy and emissions saving potential of additive manufacturing: the case of lightweight aircraft components , 2016 .

[19]  Wim Dewulf,et al.  Methodology for systematic analysis and improvement of manufacturing unit process life cycle inventory (UPLCI) Part 1: Methodology Description , 2011 .

[20]  Nicolas Serres,et al.  Environmental comparison of MESO-CLAD® process and conventional machining implementing life cycle assessment , 2011 .

[21]  Hao Tang,et al.  An operation-mode based simulation approach to enhance the energy conservation of machine tools , 2015 .

[22]  Yaoyao Fiona Zhao,et al.  A framework to reduce product environmental impact through design optimization for additive manufacturing , 2016 .

[23]  Ian A. Ashcroft,et al.  ENERGY INPUTS TO ADDITIVE MANUFACTURING: DOES CAPACITY UTILIZATION MATTER? , 2011 .

[24]  Sami Kara,et al.  Carbon emissions and CES™ in manufacturing , 2008 .

[25]  Ryan R. Dehoff,et al.  Recyclability Study on Inconel 718 and Ti-6Al-4V Powders for Use in Electron Beam Melting , 2016, Metallurgical and Materials Transactions B.

[26]  Sangkee Min,et al.  Development of an energy consumption monitoring procedure for machine tools , 2012 .

[27]  Paolo Claudio Priarone,et al.  Modelling of specific energy requirements in machining as a function of tool and lubricoolant usage , 2016 .

[28]  Giuseppe Ingarao,et al.  A methodology for evaluating the influence of batch size and part geometry on the environmental performance of machining and forming processes , 2016 .

[29]  Sami Kara,et al.  Unit process energy consumption models for material removal processes , 2011 .

[30]  Andres F. Clarens,et al.  A Review of Engineering Research in Sustainable Manufacturing , 2013 .

[31]  G. Psacharopoulos Overview and methodology , 1991 .