{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T16:08:02Z","timestamp":1773763682176,"version":"3.50.1"},"reference-count":56,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,2,27]],"date-time":"2022-02-27T00:00:00Z","timestamp":1645920000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Processes"],"abstract":"<jats:p>Metal matrix syntactic foams (MMSFs) are advanced lightweight materials constituted by a metallic matrix and a dispersion of hollow\/porous fillers. Physical and mechanical properties can be fitted regarding matrix and filler properties and processing parameters. Their properties make them potential materials for sectors where density is a limiting parameter, such as transport, marine, defense, aerospace, and engineering applications. MMSFs are mainly manufactured by powder metallurgy, infiltration, and stir casting techniques. This study focuses on the current stir casting approaches and on the advances and deficiencies, providing processing parameters and comparative analyses on porosity and mechanical properties. PRISMA approaches were followed to favor traceability and reproducibility of the study. Stir casting techniques are low-cost, industrially scalable approaches, but they exhibit critical limitations: buoyancy of fillers, corrosion of processing equipment, premature solidification of molten metal during mixing, cracking of fillers, heterogeneous distribution, and limited incorporation of fillers. Six different approaches were identified; four focus on limiting buoyancy, cracking, heterogeneous distribution of fillers, and excessive oxidation of sensitive matrix alloys to oxygen. These improvements favor reaching the maximum porosity of 54%, increasing the fillers\u2019 size from a few microns to 4\u20135 mm, reducing residual porosity by \u00b14%, synthesizing bimodal MMSFs, and reaching maximum incorporation of 74 vol%.<\/jats:p>","DOI":"10.3390\/pr10030478","type":"journal-article","created":{"date-parts":[[2022,2,27]],"date-time":"2022-02-27T20:48:33Z","timestamp":1645994913000},"page":"478","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Stir Casting Routes for Processing Metal Matrix Syntactic Foams: A Scoping Review"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2232-4439","authenticated-orcid":false,"given":"Alejandro Miguel","family":"S\u00e1nchez de la Muela","sequence":"first","affiliation":[{"name":"Department of Geologic and Mining Engineering, Escuela T\u00e9cnica Superior de Ingenieros de Minas y Energ\u00eda, Universidad Polit\u00e9cnica de Madrid, 28003 Madrid, Spain"},{"name":"Associated Laboratory for Energy, Transport and Aeronautics, LAETA (PROA), Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5856-5317","authenticated-orcid":false,"given":"Joana","family":"Duarte","sequence":"additional","affiliation":[{"name":"Associated Laboratory for Energy, Transport and Aeronautics, LAETA (PROA), Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8524-5503","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Santos Baptista","sequence":"additional","affiliation":[{"name":"Associated Laboratory for Energy, Transport and Aeronautics, LAETA (PROA), Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal"}]},{"given":"Luis Enrique","family":"Garc\u00eda Cambronero","sequence":"additional","affiliation":[{"name":"Department of Geologic and Mining Engineering, Escuela T\u00e9cnica Superior de Ingenieros de Minas y Energ\u00eda, Universidad Polit\u00e9cnica de Madrid, 28003 Madrid, Spain"}]},{"given":"Jos\u00e9 Manuel","family":"Ruiz-Rom\u00e1n","sequence":"additional","affiliation":[{"name":"Department of Geologic and Mining Engineering, Escuela T\u00e9cnica Superior de Ingenieros de Minas y Energ\u00eda, Universidad Polit\u00e9cnica de Madrid, 28003 Madrid, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4566-333X","authenticated-orcid":false,"given":"Francisco Javier","family":"Elorza","sequence":"additional","affiliation":[{"name":"Department of Geologic and Mining Engineering, Escuela T\u00e9cnica Superior de Ingenieros de Minas y Energ\u00eda, Universidad Polit\u00e9cnica de Madrid, 28003 Madrid, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"962","DOI":"10.1016\/j.jallcom.2018.07.215","article-title":"Quasi Static and Dynamic Compression of Zinc Syntactic Foams","volume":"768","author":"Broxtermann","year":"2018","journal-title":"J. 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