Aluminum_Applications_in_the_Rail_Industry

14 while previous studies showed that scandium

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Unformatted text preview: on stir welding, to improve the performance of aluminum alloys for rail applications.14 While previous studies showed that scandium additions improved weldability of 6061 alloy, this study demonstrated that scandium additions reduced the strength of 6061 and did not refine the grain size. In the case of the 5456 alloy, the addition of scandium did refine the grain structure and improve mechanical properties; however, the intergranular corrosion performance was adversely impacted. In the case of the 7xxx alloy, however, scandium additions did significantly improve mechanical properties, weldability, and corrosion resistance. Because of higher  LIGHT METAL AGE, OCTOBER 2007 mechanical properties, however, the extrusion rate of this alloy is somewhat slower, and hence production costs can be expected to be higher. So the trade-off is whether the improvements in mechanical properties, weldability, and corrosion resistance from the scandium addition to the 7xxx alloy are sufficient to overcome some increase in material cost. To date, scandium has only been used in relatively small quantities in high performance sporting goods such as baseball bats and arc...
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This note was uploaded on 01/27/2014 for the course CM 312 taught by Professor Mariowriedt during the Spring '10 term at Clarkson University .

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