The idea is based on the formation of secondary fine heat-resistant [Al.sub.3]M
dispersoids, where "M" is a transition element such as Zr, Ni, and Mn [10, 12].
* The 224 alloys with added
dispersoids resulted in superior creep strength to similar 319 alloys under comparable loading and temperature.
The average diameter of gloomy sphere was similar to the volume mean particle diameter of the
dispersoid present in natural rubber latex, which is about 0.7 jam in diameter.
In precipitation-hardened aluminum alloys, the key manifestation of this phenomenon is the development of
dispersoids, tiny clumps of metal oxides called Guinier-Preston zones.
High-magnification photo (Figure 1(d)) clearly exhibits the fine
dispersoid particles precipitated during the solutionizing course of the Al-Cu-Mn alloys.
However, here one has to consider the retarding effect due to the presence of
dispersoid particles.
After polymerization, the resulting
dispersoid of polymerized beads was poured into 600 ml of boiling water; the water temperature was maintained for 15 min while stirring at 150 rpm, and then filtrated to obtain the polymer beads.
Dispersoid colonies typically result from oxidation of localized concentrations of magnesium that form during alloying malpractice.
The melting points of Al[B.sub.2] and Al[B.sub.12] are 1665 [+ or -] 50[degrees]C and 2163 [+ or -] 50[degrees]C, respectively, resulting in the formation of solid
dispersoid particles in the molten liquid [6].
Sommer, "
Dispersoid stability in a Cu-[Al.sub.2][O.sub.3] alloy under energetic cascade damage conditions," Journal of Nuclear Materials, vol.
McCormack, "
Dispersoid additions to a Pb-free solder for suppression of microstructural coarsening," Journal of Electronic Materials, vol.
The XRD plots in Figure 7(b) show that the alloy "A" sample after T6 temper exhibits
dispersoid compound phases ([Mg.sub.2][Zn.sub.11], Mg[Zn.sub.2], [Al.sub.75][Ni.sub.10][Fe.sub.15], and [Al.sub.4][Ni.sub.3]) in addition to the compounds already existing in the as quenched sample of alloy A.