Editing Syntactic foam (section)

{{short description|Composite material filled with low-density spheres}}

{{use dmy dates|date=May 2018}}

{{redirect-synonym|composite foam|[[foamcore]]<!--foam concrete-->}}

[[file:syntacticfoam.JPG|upright=1.3|thumb|Syntactic foam, shown by [[scanning electron microscope|scanning electron microscopy]], consisting of [[glass microsphere]]s within a matrix of [[epoxy]] resin.]]

'''Syntactic foams''' are [[composite material]]s synthesized by filling a [[metal]], [[polymer]],<ref>{{cite journal|last=Shutov|first=F.A.|title=Syntactic polymer foams|journal=Advances in Polymer Science|year=1986|volume=73-74|pages=63–123|doi=10.1007/3-540-15786-7_7|isbn=978-3-540-15786-1}}</ref> [[cement]]itious or [[ceramic]] matrix with
spheres as [[Aggregate (composite)|aggregates]].<ref name="lm2">{{Cite web|url=http://www.crgrp.com/technology/portfolio/syntactics.html|title=What is Syntactic Foam?|access-date=2009-08-07|publisher=Cornerstone Research Group|url-status=dead|archive-url=https://web.archive.org/web/20120720033636/http://www.crgrp.com/technology/portfolio/syntactics.html|archive-date=20 July 2012|df=dmy-all}}</ref> The spheres may be hollow, called [[microballoon]]s<ref>{{cite journal |first1=Ho Sung |last1=Kim |first2=Pakorn |last2=Plubrai |title=Manufacturing and failure mechanisms of syntactic foam under compression |journal=Composites Part A: Applied Science and Manufacturing |volume=35 |issue=9 |date=September 2004 |pages=1009–1015 |doi=10.1016/j.compositesa.2004.03.013}}</ref> or [[cenosphere]]s, or non-hollow, for example [[perlite]].<ref>{{cite journal |first1=Dipendra |last1=Shastri |first2=Ho Sung |last2=Kim |title=A new consolidation process for expanded perlite particles |journal=Construction and Building Materials |volume=60 |date=16 June 2014 |pages=1–7 |doi=10.1016/j.conbuildmat.2014.02.041|hdl=1959.13/1052767 |hdl-access=free }}</ref> In this context, "syntactic" means "put together."<ref name="Merriam-Webster">{{cite Merriam-Webster|syntactic foam|accessdate=2023-06-22}}</ref> The presence of hollow particles results in lower [[density]], higher [[specific strength]] (strength divided by density), lower [[coefficient of thermal expansion]], and, in some cases, [[radar]] or [[sonar]] [[stealth technology|transparency]].