Study of microstructure and ageing characteristic of aluminium alloy reinforced with glass particulates
Study on microstructure and ageing characteristics has been done on the aluminium alloy reinforced with glass particulates. Aluminium - 4 wt. % copper composites were produced by powder metallurgy technique. Composition of 0, 5, 10, 15, 20 and 25 wt. % glass particulates was mixed into aluminium...
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| Format: | Thesis |
| Language: | English |
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| Online Access: | http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/9885/1/Page%201-24.pdf http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/9885/2/Full%20Text.pdf |
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| Summary: | Study on microstructure and ageing characteristics has been done on the aluminium
alloy reinforced with glass particulates. Aluminium - 4 wt. % copper composites were
produced by powder metallurgy technique. Composition of 0, 5, 10, 15, 20 and 25 wt.
% glass particulates was mixed into aluminium - 4 wt. % copper alloy. All composites
were fabricated by mixing, pressing and sintering. The sintering was performed at 548º
C. Ageing of the composites was done by solution heat treatment at 510º C followed by
quenched rapidly into cool water and artificial aged for 10 hours at 160º C.
XRD and DSC analysis showed the precipitation formation in unreinforced and
reinforced Al - 4 wt. % Cu alloy. Unreinforced Al – 4 wt. % Cu alloy showed the
precipitation of Al2Cu during sintering, but after solution treatment Al2Cu detected as
small peak by XRD. It is indicated that Al2Cu did not completely dissolved. In addition,
reinforced Al - 4 wt. % Cu alloy with glass particulates showed precipitation of Al2Cu
during sintering but after solution treatment, undissolved precipitates were observed at
the interface between glass particulates and the aluminium matrix. It showed
incomplete dissolution. Ageing has influenced the precipitation formation in the
composite because Al2Cu indicated higher intensity of XRD pattern as compared to the
composite without ageing.
The microstructures of the composites showed that the glass particulates were
homogenously distributed in the matrix. However, glass particulates with the
composition of 10, 15, 20 and 25 wt. % were found segregated near copper. The
formation of AlCu and Al2Cu phases was interfered by the presence of glass
particulates. The aluminium oxide layer in the matrix is produced between aluminium,
copper and glass particulate. It is harder than matrix that indicated by micro cracks in
aluminium oxide layer and at interface between aluminium oxide layer and aluminium.
Furthermore, it was found an increase in the hardness of matrix and that is found
responsible for hardening mechanism.
After sintering, hardness value indicated that the composite with 25 wt. % glass had
highest hardness i.e. 34.87 HV than unreinforced aluminum alloy i.e. 15.83 HV. The
hardness value increased with increasing the glass composition in the aluminium alloy.
Ageing kinetic of the composites was slower than unreinfoced aluminium alloy. The
slow ageing kinetic was expected due to the presence of glass particulates which
disturbed precipitate formation of aluminium-copper and delay the G.P. zone formation. |
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