scholarly journals Effect of Silicon Addition on Oxidation Resistance and Mechanical Properties of Fe-Al-Cr-Ti Alloys

1974 ◽  
Vol 38 (6) ◽  
pp. 533-538
Author(s):  
Seiichi Ikeda ◽  
Goro Ito
Keyword(s):  
Mechanical Properties ◽  
Oxidation Resistance ◽  
Ti Alloys ◽  
Silicon Addition

scholarly journals Effect of Silicon Addition on Microstructure and Mechanical Properties of Chromium and Titanium Based Coatings

2014 ◽  
Vol 23 (37) ◽  
pp. 9 ◽  
Author(s):  
Luis Carlos Ardila-Téllez ◽  
José Manuel Sánchez-Moreno ◽  
Carlos Mauricio Moreno-Téllez
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Crystallite Size ◽  
Oxidation Resistance ◽  
Columnar Structure ◽  
Size Refinement ◽  
Silicon Addition ◽  
Transmission Electron ◽  
Before And After ◽  
Size Growth

<p>The changes in the microstructure, mechanical properties and residual stresses of AlTiN, AlTiSiN, AlCrN and AlCrSiN coatings, has been studied before and after annealing at 900 ºC and 1100 ºC, using scanning and transmission electron microscopy, along with nano-indentation and X-ray diffraction techniques. The As-deposited coatings show a columnar structure, with a crystallite size between 18 nm and 28 nm. Despite the silicon addition, no effect on the crystallite size refinement was observed.<br />However, the addition of silicon increases hardness, elastic modulus and compressive residual stresses. After annealing at 900 ºC, the crystallite size growth and the residual stress relaxes; therefore, the coating hardness decreases. At 1100 ºC, the oxide layers formed in AlTiN and AlTiSiN, which act as protective layers enhancing oxidation resistance; meanwhile, a complete oxidation of AlCrN and AlCrSiN coatings take place. The Titanium based coatings present some superior mechanical properties and oxidation resistance than the chromium based coatings at 900 ºC and 1100 ºC.</p>

scholarly journals Chromium-Based Alloys Strengthened by Ordered Phase Precipitation for Gas Turbine Applications

2011 ◽  
Vol 278 ◽  
pp. 569-574 ◽  
Author(s):  
Didier Locq ◽  
Pierre Caron ◽  
Catherine Ramusat ◽  
Rémy Mévrel
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Gas Turbine ◽  
Oxidation Resistance ◽  
Alumina Scale ◽  
High Melting ◽  
Phase Precipitation ◽  
High Melting Point ◽  
Ti Alloys ◽  
Aero Engine

Chromium-based alloys are considered as potential candidates for applications in hot sections of aero engine turbines due to their high melting point and their moderate density. Some ternary (Cr-Ni-Al) and quaternary (Cr-Ni-Al-Ti) alloys have been designed with the aim to induce precipitation of ordered strengthening precipitates and to promote the formation of a protective alumina scale. These alloys were cast using various techniques in order to assess their microstructural and mechanical properties and their oxidation resistance.

scholarly journals First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Salloom ◽  
S. A. Mantri ◽  
R. Banerjee ◽  
S. G. Srinivasan
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
First Principles ◽  
Young's Modulus ◽  
Group Vi ◽  
Group V ◽  
Β Phase ◽  
Ti Alloys ◽  
Ω Phase ◽  
Stabilizer Concentration

AbstractFor decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experiments. We show that the elastic properties of the ω-phase can be systematically varied as a function of its composition to enhance both the ductility and strength of the Ti-alloy. Studies with five prototypical β-stabilizer solutes (Nb, Ta, V, Mo, and W) show that increasing β-stabilizer concentration destabilizes the ω-phase, in agreement with experiments. The Young’s modulus of ω-phase also decreased at larger concentration of β-stabilizers. Within the region of ω-phase stability, addition of Nb, Ta, and V (Group-V elements) decreased Young’s modulus more steeply compared to Mo and W (Group-VI elements) additions. The higher values of Young’s modulus of Ti–W and Ti–Mo binaries is related to the stronger stabilization of ω-phase due to the higher number of valence electrons. Density of states (DOS) calculations also revealed a stronger covalent bonding in the ω-phase compared to a metallic bonding in β-phase, and indicate that alloying is a promising route to enhance the ω-phase’s ductility. Overall, the mechanical properties of ω-phase predicted by our calculations agree well with the available experiments. Importantly, our study reveals that ω precipitates are not intrinsically embrittling and detrimental, and that we can create Ti-alloys with both good ductility and strength by tailoring ω precipitates' composition instead of completely eliminating them.

Mechanical properties and oxidation resistance of Mo-Si-B and Mo-Hf-Si-B coatings obtained by magnetron sputtering in DC and pulsed DC modes

2020 ◽  
Vol 403 ◽  
pp. 126373 ◽  
Author(s):  
Ph.V. Kiryukhantsev-Korneev ◽  
A.D. Sytchenko ◽  
A.Yu. Potanin ◽  
S.A. Vorotilo ◽  
E.A. Levashov
Keyword(s):  
Mechanical Properties ◽  
Magnetron Sputtering ◽  
Oxidation Resistance ◽  
Pulsed Dc
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