TY - JOUR
T1 - Oxynitride dendritic strengthening in pre-melted aluminium flakes through controlled in situ nitridation
AU - Chernousov, Andrey A.
AU - Chan, Ben Y.B.
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/10/25
Y1 - 2019/10/25
N2 - In situ nitridation of pre-compacted aluminium flakes is shown to be a key to lightweight composites for many engineering applications such as more efficient and cost-effective construction vehicles. This new composite has the mechanical properties of high-strength streels while being ∼3.4 times lighter. This composite was produced by: (i) compaction of micrometric Al flakes into porous blanks, (ii) partial melting through rapid heating to 870 K in N2 and (iii) annealing of the pre-melted blanks at 750 K in N2, where different Al flake deoxidisers were used to control a sufficiently low level of H2O/O2 activating in situ nitridation. The nitrided composites contained stellar dendrites composed of Al, AlN and γ-Al2O3, in which the ceramic fraction increases over the nitridation stage. The traces of H2O in the N2 atmosphere were found to be beneficial for strengthening, due to oxidation and suppression of the composite dendrites from overgrowing and segregation.
AB - In situ nitridation of pre-compacted aluminium flakes is shown to be a key to lightweight composites for many engineering applications such as more efficient and cost-effective construction vehicles. This new composite has the mechanical properties of high-strength streels while being ∼3.4 times lighter. This composite was produced by: (i) compaction of micrometric Al flakes into porous blanks, (ii) partial melting through rapid heating to 870 K in N2 and (iii) annealing of the pre-melted blanks at 750 K in N2, where different Al flake deoxidisers were used to control a sufficiently low level of H2O/O2 activating in situ nitridation. The nitrided composites contained stellar dendrites composed of Al, AlN and γ-Al2O3, in which the ceramic fraction increases over the nitridation stage. The traces of H2O in the N2 atmosphere were found to be beneficial for strengthening, due to oxidation and suppression of the composite dendrites from overgrowing and segregation.
KW - Aluminium flake powder
KW - Aluminium nitride dendrites
KW - In situ nitridation
KW - Porous AlN AlO compounds
KW - Syntactic aluminium foam
UR - https://www.webofscience.com/wos/woscc/full-record/WOS:000485039800093
UR - https://openalex.org/W2961108184
UR - https://www.scopus.com/pages/publications/85069963461
U2 - 10.1016/j.jallcom.2019.07.201
DO - 10.1016/j.jallcom.2019.07.201
M3 - Journal Article
SN - 0925-8388
VL - 806
SP - 841
EP - 851
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
ER -