Elevated-Temperature Static and Dynamic Sea-Salt Stress Cracking of Titanium Alloys

2009 ◽  
pp. 1-1-30
2015 ◽  
Vol 48 (4) ◽  
pp. 39-50 ◽  
Author(s):  
K.M. Saad-Allah

AbstractSix varieties of soybean (Glycine max L.) plants were grown for 30 days under three levels of sea salt salinity (0.0, 8.0 and 16.0 mS/cm2) for studying the effect of sea salt on uptake of nitrate and response of the antioxidant system for these salinity doses. Salt treatments resulted in a gradual decline in nitrate uptake by increasing sea salt concentration, which mean that this will bring negative consequences on nitrogen assimilation. However, salt treatments induced the accumulation of hydrogen peroxide and glycinebetaine in the leaves of all soybean verities as an adaptive strategy to cope with salt stress. On the other hand, there was a differential response in phenolic compounds among soybean verities as a function of salt concentration and the studied variety, which means there has a decline in phenolics under salt stress in the varieties Crawford, G21, G22 and G83, but in contrary in G35 and G82, phenolics has accumulated in response to salinity. Isozymes electrophoretic banding showed changes in peroxidase activity with sea salt, however superoxide dismutase showed stability in number and intensity of bands with salt treatments. Esterase enzyme was more sensitive to salinity and showed a gradual decline in activity by increasing salt concentration.


2020 ◽  
Vol 321 ◽  
pp. 04006
Author(s):  
John Mantione ◽  
Matias Garcia-Avila ◽  
Matthew Arnold ◽  
David Bryan ◽  
John Foltz

The attractive combination of strength and low density has resulted in titanium alloys covering 15 to 25% of the weight of a modern jet engine, with titanium currently being used in fan, compressor and nozzle components. Typically, titanium alloys used in jet engine applications are selected from the group of near alpha and alpha-beta titanium alloys, which exhibit superior elevated temperature strength, creep resistance and fatigue life compared to typical titanium alloys such as Ti-6Al-4V. Legacy titanium alloys for elevated temperature jet engine applications include Ti-5Al-2Sn-2Zr-4Mo-4Cr, Ti-6Al-2Sn-4Zr-2Mo-0.1Si and Ti-4Al-4Mo-2Sn-0.5Si. Improving the mechanical behavior of these alloys enables improved component performance, which is crucial to advancing jet engine performance. As a world leader in supplying advanced alloys of titanium, nickel, cobalt, and specialty stainless steels, ATI is developing new titanium alloys with improved elevated temperature properties. These improved properties derive from precipitation of secondary intermetallics in alpha-beta titanium alloys. ATI has developed several new alpha-beta titanium alloy compositions which exhibit significantly improved elevated temperature strength and creep resistance. This paper will focus on the effects of chemistry and heat treat conditions on the microstructure and resulting elevated temperature properties of these new aerospace titanium alloys.


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