Comparative Study on Compaction and Sintering Behavior
of Spray and Freeze Granulated Magnesium Aluminate
Spinel Powder |
Swathi Manivannan,1 Papiya Biswas,1,* Prasenjit Barick,1 Sweety Kumari,2 Bhaskar Prasad Saha1
and Roy Johnson1
Pages : 110-117
DOI : 10.1080/0371750X.2021.1887765 |
Abstract |
Commercially procured magnesium aluminate (MgAl2O4) spinel powder with average
particle size of 300 nm and irregular morphology were spray and freeze granulated.
The granules were characterized for the texture, strength, granule size and its
distribution. In order to evaluate the flowability of granules, rheological parameters,
such as Carr index and Hausner ratio were measured. The granules were further
subjected to quasi-static compaction under loading, unloading conditions and
compaction curves were constructed. Compaction coefficients thus obtained were
correlated with granulation conditions and other parameters including green densities.
Compacted green samples were also subjected to flexural strength measurements
following ASTM standards and fractographs were observed under FESEM. A Carr
index of 13.7 and Hausner ratio of 1.16 were obtained for freeze dried granules
indicating the superiority in flow behavior as compared to its spray granulated
counterpart, thereby showing a better compaction behavior: compaction coefficient
of 5.9 in combination with higher true and predicted green density values and lower
granule strength of 1.22 MPa. The green samples exhibited a flexural strength of
11 and 12.5 MPa and compressive strength of 2.44 and 1.22 MPa for spray and freeze
granulated sample, respectively. The above observations were also complemented
by the fractographs.
[Keywords: Spray granulation, Freeze granulation, Spinel, Compaction curve] |
Full text : Subscribe to Download Full Text |
[Go Back] |
|