Scientists at the European Space Agency( ESA) announced on November 6, 2012 that they had developed a new aircraft grade alloy that it twice as light as conventional nickel superalloys while offering equally good properties It will help aeroplanes save fuel by cutting down on weight without sacrificing safety. It is worth mentioning here that cutting weight by 1 percent will save up to 1.5 percent of fuel. For years, engineers have known that titanium aluminide alloys offer great weight benefits over the nickel superalloys used today in conventional engines.
Since the newer alloy can withstand extreme temperatures up to 800 deg C, it has generated ample interest among jet engine manufactures. However, although it is possible to make the alloy in a laboratory, casting it is the shapes required by industry, such as a turbine blade, is not simple. ESA scientists working in the "Impress" project looked into the problem. They needed to switch off as many external variables as possible It this case, they chose gravity.
Aluminium samples were heated in a small furnace carried in a sounding rocket into space. During six minutes of free fall, they were heated to over 700 deg C, and then monitored by X-rays as they cooled. Looking at the results, the scientists released that casting titanium aluminides might require looking in the opposite direction: hypergravity. In hypergravity conditions, casting the metals in a centrifuge creating up to 20 times normal gravity helped the liquid metals to fill every part of a mould, producing a perfectly cast alloy. Analyzing metal casting in as many ways as possibles produced building blocks of knowledge that allow the industrial process to be refined and commercialized.
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