materials Review Powder Bed Fusion Additive Manufacturing Using Critical Raw Materials: A Review Vladimir V. Popov 1,* , Maria Luisa Grilli 2 , Andrey Koptyug 3 , Lucyna Jaworska 4 , Alexander Katz-Demyanetz 1 , Damjan Klobˇcar 5 , Sebastian Balos 6 , Bogdan O. Postolnyi 7,8 and Saurav Goel 9,10,11 1 Israel Institute of Metals, Technion R&D Foundation, Haifa 3200003, Israel; [email protected] 2 ENEA–Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Energy Technologies and Renewable Sources Department, Casaccia Research Centre, Via Anguillarese 301, 00123 Rome, Italy; [email protected] 3 SportsTech Research Center, Mid Sweden University, Akademigatan 1, SE-83125 Östersund, Sweden; [email protected] 4 Faculty of Non-Ferrous Metals, AGH University of Science and Technology, 30-059 Krakow, Poland; [email protected] 5 Faculty of Mechanical Engineering, University of Ljubljana, Aškerˇcevac. 6, 1000 Ljubljana, Slovenia; [email protected] 6 Department of Production Engineering, Faculty of Technical Science, University of Novi Sad, Novi Sad, Trg Dositeja Obradovica 6, 21000 Novi Sad, Serbia; [email protected] 7 IFIMUP—Institute of Physics for Advanced Materials, Nanotechnology and Photonics, Department of Physics and Astronomy, Faculty of Sciences, University of Porto, 687 Rua do Campo Alegre, Citation: Popov, V.V.; Grilli, M.L.; 4169-007 Porto, Portugal; [email protected] 8 Department of Nanoelectronics and Surface Modification, Sumy State University, 2 Rymskogo-Korsakova St., Koptyug, A.; Jaworska, L.; 40007 Sumy, Ukraine Katz-Demyanetz, A.; Klobˇcar, D.; 9 School of Engineering, London South Bank University, London SE1 0AA, UK; [email protected] Balos, S.; Postolnyi, B.O.; Goel, S. 10 School of Aerospace, Transport and Manufacturing, Cranfield University, Cranfield MK4 30AL, UK Powder Bed Fusion Additive 11 Department of Mechanical Engineering, Shiv Nadar University, Gautam Budh Nagar 201314, India Manufacturing Using Critical Raw * Correspondence: [email protected] Materials: A Review. Materials 2021, 14, 909. https://doi.org/10.3390/ Abstract: The term “critical raw materials” (CRMs) refers to various metals and nonmetals that are ma14040909 crucial to Europe’s economic progress. Modern technologies enabling effective use and recyclability of CRMs are in critical demand for the EU industries. The use of CRMs, especially in the fields of Academic Editors: biomedicine, aerospace, electric vehicles, and energy applications, is almost irreplaceable. Additive Antonino Squillace and Maria manufacturing (also referred to as 3D printing) is one of the key enabling technologies in the field of Letizia Ruello manufacturing which underpins the Fourth Industrial Revolution. 3D printing not only suppresses Received: 9 January 2021 waste but also provides an efficient buy-to-fly ratio and possesses the potential to entirely change Accepted: 5 February 2021 supply and distribution chains, significantly reducing costs and revolutionizing all logistics. This Published: 14 February 2021 review provides comprehensive new insights into CRM-containing materials processed by modern additive manufacturing techniques and outlines the potential for increasing the efficiency of CRMs Publisher’s Note: MDPI stays neutral utilization and reducing the dependence on CRMs through wider industrial incorporation of AM with regard to jurisdictional claims in and specifics of powder bed AM methods making them prime candidates for such developments. published maps and institutional affil- iations. Keywords: additive manufacturing; critical raw materials; CRM; recyclability; powders for additive manufacturing; powder bed fusion Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. 1. Introduction This article is an open access article There is a growing global concern about securing access to metals and minerals distributed under the terms and needed for developing economic production. The dependence of industrial sectors on conditions of the Creative Commons scarce materials, in many cases almost entirely dependent on remote sources, represents a Attribution (CC BY) license (https:// threat to the future competitiveness of highly import-dependent industrialized countries creativecommons.org/licenses/by/ such as the European Union (EU) member states, Japan, and the United States. It is also 4.0/). Materials 2021, 14, 909. https://doi.org/10.3390/ma14040909 https://www.mdpi.com/journal/materials Materials 2021, 14, 909 2 of 37 Materials 2021, 14, 909 2 of 37 a threat to the future competitiveness of highly import-dependent industrialized countries such as the European Union (EU) member states, Japan, and the United States. It is also complementedcomplemented by bythe theadditional additional challenge challenge of sustainable of sustainable management management of all of resources all resources startingstarting from from raw raw materials materials through through manufacturing manufacturing and andlogistics logistics to waste to waste treatment treatment and and end-of-lifeend-of-life product product recycling. recycling. CriticalCritical raw raw materials materials (CRMs) (CRMs) are areraw rawmaterials materials of high of highimportance importance to the to global the global economy.economy. Their Their supply supply is at is risk, at risk, as defined as defined in the in curren the currentt methodology methodology for raw for materials raw materials assessmentassessment published published by the by theEuropean European Commission Commission (EC) (EC) in 2017 in2017 [1]. European [1]. European legislators legislators werewere already already pointing pointing out outthe thecriticality criticality of the of raw the rawmaterial material for quite for quite a while, a while, indicating indicating thatthat this this issue issue is economic is economic as well as well as political. as political. In 2007, In 2007, the EU the Council EU Council declared declared the Con- the Con- clusionsclusions on onIndustrial Industrial Policy, Policy, requesting requesting the Commission the Commission to develop to develop a coherent a coherent approach approach forfor raw raw material material supply supply to EU to EUindustries. industries. The Thecorresponding corresponding approach approach needed needed to cover to cover all allrelevant relevant areas areas of policy of policy (foreign (foreign affairs, affairs, trade, trade, environmental, environmental, development, development, and re- and re- searchsearch and and innovation innovation policy) policy) and and identify identify appropriate appropriate measures measures for forcost-effective, cost-effective, relia- reliable, ble,and and environmentally environmentally friendlyfriendly access to to an andd exploitation exploitation of of natural natural resources, resources, second- secondary aryraw raw materials, materials, andand recyclablerecyclable waste, espe especiallycially concerning concerning thir third-countryd-country markets markets [2]. [2 ]. In In response, the the first first European European Raw Raw Materials Materials Initiative Initiative was was launched launched by by the the EC EC in in2008 2008 to to provide a a fair fair and and sustainable sustainable supply supply of ofraw raw materials materials from from international international markets markets and and thethe EU, EU, while while promoting promoting resource resource efficiency efficiency and andcircular circular economy economy [3]. The [3]. first The CRMs first CRMs list list waswas released released in 2011 in 2011 and and contained contained 41 candidates, 41 candidates, of which of which 14 CRMs 14 CRMs were wereselected selected [4] as [4] as supercritical.supercritical. In 2014, In 2014, the CRMs the CRMs list was list upda wasted, updated, and 20 and CRMs 20 CRMswere identified were identified out of 54 out of candidates54 candidates [5]. A third [5]. A CRMs third CRMslist with list 26 with raw 26materials raw materials and groups and of groups raw materials of raw materials out of theout 78 of candidates the 78 candidates was released was released in 2017 [6]. in 2017 The [last6]. TheCRMs last list CRMs was released list was in released 2020 and in 2020 containedand contained 30 elements 30 elements [7]. Bauxite, [7]. Bauxite,lithium, lithium,titanium, titanium, and strontium and strontium were added were toadded the to CRMsthe CRMslist for listthe forfirst the time, first while time, helium, while helium,critical in critical 2017, was in 2017, removed was removedfrom the list from due the list to duea decline to a declinein its economic in its economic importance. importance. The CRMs The list CRMs is updated list is updated every three every years three to years accountto account for the for production, the production, market, market, and technological and technological developments. developments. A summary A summary of the of fourthe CRMs four listed CRMs above listed is above presented is presented in Figure in 1, Figurewhere1 elements, where elementslisted as CRMs listed in as 2011, CRMs in 2013,2011, 2017, 2013, and 2017, 2020 andare marked 2020 are in marked different in co differentlors. From colors. the table, From the evolution table, the of evolution criti- of calitycriticality of each ofelement each element or materi oral materialsince 2011 since is evident. 2011 is It evident. is worth It noting is worth that noting many thatother many rawother materials, raw materials, even when even not classed when not as crit classedical, are as critical,important