Editing Sintering (section)

== Microwave sintering ==
In [[microwave]] sintering, heat is sometimes generated internally within the material, rather than via surface radiative heat transfer from an external heat source. Some materials fail to couple and others exhibit run-away behavior, so it is restricted in usefulness. A benefit of microwave sintering is faster heating for small loads, meaning less time is needed to reach the sintering temperature, less heating energy is required and there are improvements in the product properties.<ref name="OghbaeiMirzaee2010">{{cite journal|last1=Oghbaei|first1=Morteza|last2=Mirzaee|first2=Omid|title=Microwave versus conventional sintering: A review of fundamentals, advantages and applications|journal=Journal of Alloys and Compounds|volume=494|issue=1–2|year=2010|pages=175–189|doi=10.1016/j.jallcom.2010.01.068}}</ref>

A failing of microwave sintering is that it generally sinters only one compact at a time, so overall productivity turns out to be poor except for situations involving one of a kind sintering, such as for artists. As microwaves can only penetrate a short distance in materials with a high [[electrical conductivity|conductivity]] and a high [[permeability (electromagnetism)|permeability]], microwave sintering requires the sample to be delivered in powders with a particle size around the penetration depth of microwaves in the particular material. The sintering process and side-reactions run several times faster during microwave sintering at the same temperature, which results in different properties for the sintered product.<ref name="OghbaeiMirzaee2010"/>

This technique is acknowledged to be quite effective in maintaining fine grains/nano sized grains in sintered [[bioceramic]]s. Magnesium phosphates and calcium phosphates are the examples which have been processed through the microwave sintering technique.<ref>{{cite journal|last1=Babaie|first1=Elham|last2=Ren|first2=Yufu|last3=Bhaduri|first3=Sarit B.|title=Microwave sintering of fine grained MgP and Mg substitutes with amorphous tricalcium phosphate: Structural, and mechanical characterization|journal=Journal of Materials Research|date=23 March 2016|volume=31|issue=8|pages=995–1003|doi=10.1557/jmr.2016.84|bibcode=2016JMatR..31..995B|s2cid=139007302 }}</ref>