A calorimetric investigation of fiber/matrix reactions in fiber-reinforced aluminum alloy 339

Synthesis of an Al/MgAl2O4In situMetal Matrix Composite from Silica Gel

“…The crystallization energy or lattice energy ( E ) of Al 2 O 3 (−14910 KJ/mol) is three to fourfold higher than that of MgO and MgAl 2 O 4 . The heat‐treatment studies of 339 Al/silica bound Kaowool (47%Al 2 O 3 /53%SiO 2 ) composites by Smith et al 31 have revealed that the higher activation energy required compared with others has resulted in the absence of Al 2 O 3 at the interface. Moreover, Lee et al 32 have modeled the MgO–MgAl 2 O 4 –Al 2 O 3 stability with various Mg contents by using oxidized SiC‐reinforced Al– X Mg alloys ( X =0.5, 1, 2, 4 wt%) and found that only MgAl 2 O 4 is stable in the alloy having a 0.002–6 wt% Mg content.…”

A study on the formation of MgAl2O4 and MgO crystals in Al–Mg/quartz composite by differential thermal analysis

“…Similarly, the total heat flow calculated by the addition of different peak temperature values separately at the same heating rate of composite samples shows much lower values compared to the alloy. The lower enthalpy of reactions (3) and (4) (−146 and −23 kJ/mol) [34] than that of Mg oxidation (6) (−602 kJ/mol) is a clear indication of reactions. The heat flow corresponding to the Si dissolution in Al-5Mg/quartz samples (Table 1) increases with the increasing heating rates.…”

“…Generally, any oxygen source is sufficient to produce MgAl 2 O 4 or MgO as a reaction product in Al-Mg alloy. The materials such as SiO 2 , Al 2 O 3 , CuO, oxidized SiC, alumino silicate, flyash, and mullite, etc., are recognized as the solid oxygen sources [5][6][7][8][9][10][11]. In addition, they are largely used as reinforcements in Al MMCs.…”

Thermodynamics and Kinetics of the Formation of Al2O3/ MgAl2O4/MgO in Al-Silica Metal Matrix Composite

“…are recognized as simpler and cheaper ceramic oxides amenable for the in-situ generation of Al 2 O 3 , MgAl 2 O 4 , and MgO in Al alloy. [23][24][25][26][27][28][29][30][31][32] The different important displacement reactions possible during the reduction of SiO 2 in Al-Mg alloy are given subsequently: [33] SiO 2 s ð Þ þ 2Mg ðlÞ ! 2MgO ðsÞ þ Si ðlÞ DG 1023K ¼ À268: 22 (Table I).…”