No abstract

No abstract

No abstract

The potential opportunities promised by nanotechnology for enabling advances in defence technologies are staggering. Although these opportunities are likely to be realised over a few decades, many advantages are currently being explored, particularly for defence applications. This review provides an insight into the capabilities offered by nanocomposites which include smart materials, harder/lighter platforms, new fuel sources and storage as well as novel medical applications. It discusses polymer-based nanocomposite materials, nanoscale fillers and provides examples of the actual and potential uses of nanocomposite materials in defence with practical examples.

Grain refinement in Al-Si alloys with silicon contents in the range of 0•2-30 wt-% has been studied in detail with conventional as well as higher level additions of a Al-5T i-1B master alloy. A poisoning eVect was observed with Al-Si alloys containing Á7 wt-%Si and the extent of poisoning increased with an increase in the silicon content. Silicon improves the grain refining behaviour of aluminium when added in small quantities (0•2%). Magnesium can counteract the poisoning eVect of silicon. T he optimum level of magnesium required to overcome the poisoning eVect depends on the silicon content of the alloy. Higher level additions of a grain refiner could overcome the poisoning eVect of silicon and the level required to achieve good grain refinement is a function of the silicon and magnesium contents of the alloy. T he present paper also reports the influence of degasser and melt temperature on the grain refining response of Al-Si alloys.MST /4231

No abstract

No abstract

No abstract