Evaluation and Characterization of Iron- and Nickel-Based Alloys for Microturbine Recuperators

2005 ◽  
Author(s):  
Edgar Lara-Curzio ◽  
R. Trejo ◽  
K. L. More ◽  
P. J. Maziasz ◽  
B. A. Pint
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Corrosion Resistance ◽  
Ultimate Tensile Strength ◽  
Exhaust Gases ◽  
Exposure Temperature ◽  
Mechanical Properties And Corrosion ◽  
Strength And Ductility ◽  
Turbine Exhaust

The effects of stress, temperature and time of exposure to microturbine exhaust gases on the mechanical properties and corrosion resistance of alloys HR-120® and 230® was investigated at turbine exhaust temperatures between 620°C and 760°C. It was found that the ultimate tensile strength and ductility of alloy 230® decreased by 30% and 60%, respectively, after 500 hours exposure at 752°C. At the lowest exposure temperature of 679°C the ultimate tensile strength and ductility decreased by 10% and 25%, respectively. The ultimate tensile strength and ductility of HR-120® alloy decreased by 15% and 50%, respectively, after 500 hours exposure at 745°C. At the lowest exposure temperature of 632°C the ultimate tensile strength and ductility decreased by 10% and 23%, respectively. The microstructural changes associated with exposure to microturbine exhaust gases are analyzed and discussed.

scholarly journals Microstructures, Mechanical Properties, and Corrosion Behavior of As-Cast Mg–2.0Zn–0.5Zr–xGd (wt %) Biodegradable Alloys

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1564 ◽  
Author(s):  
Huai Yao ◽  
Jiuba Wen ◽  
Yi Xiong ◽  
Ya Liu ◽  
Yan Lu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Corrosion Resistance ◽  
Ultimate Tensile Strength ◽  
Uniform Corrosion ◽  
Moderate Amount ◽  
Long Period ◽  
Lpso Structure ◽  
Mechanical Properties And Corrosion ◽  
Corrosion Mode

The Mg–Zn–Zr–Gd alloys belong to a group of biometallic alloys suitable for bone substitution. While biocompatibility arises from the harmlessness of the metals, the biocorrosion behavior and its origins remain elusive. Here, aiming for the tailored biodegradability, we prepared the Mg–2.0Zn–0.5Zr–xGd (wt %) alloys with different Gd percentages (x = 0, 1, 2, 3, 4, 5), and studied their microstructures and biocorrosion behavior. Results showed that adding a moderate amount of Gd into Mg–2.0Zn–0.5Zr alloys will refine and homogenize α-Mg grains, change the morphology and distribution of (Mg, Zn)3Gd, and lead to enhancement of mechanical properties and anticorrosive performance. At the optimized content of 3.0%, the fishbone-shaped network, ellipsoidal, and rod-like (Mg, Zn)3Gd phase turns up, along with the 14H-type long period stacking ordered (14H-LPSO) structures decorated with nanoscale rod-like (Mg, Zn)3Gd phases. The 14H-LPSO structure only exists when x ≥ 3.0, and its content increases with the Gd content. The Mg–2.0Zn–0.5Zr–3.0Gd alloy possesses a better ultimate tensile strength of 204 ± 3 MPa, yield strength of 155 ± 3 MPa, and elongation of 10.6 ± 0.6%. Corrosion tests verified that the Mg–2.0Zn–0.5Zr–3.0Gd alloy possesses the best corrosion resistance and uniform corrosion mode. The microstructure impacts on the corrosion resistance were also studied.

Screening and Evaluation of Materials for Microturbine Recuperators

2004 ◽  
Author(s):  
Edgar Lara-Curzio ◽  
R. Trejo ◽  
K. L. More ◽  
P. A. Maziasz ◽  
B. A. Pint
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Tensile Stress ◽  
Mixed Oxides ◽  
Test Facility ◽  
Mechanical Properties And Corrosion ◽  
Metallic Foils ◽  
Strength And Ductility

The effects of stress, temperature and exposure to microturbine exhaust gases on the mechanical properties and corrosion resistance of candidate materials for microturbine recuperators were investigated. Results are presented for 347 stainless steel metallic foils after 500-hr exposure to temperatures between 620°C and 760°C at a tensile stress of 50 MPa. It was found that the material experienced accelerated attack at the highest temperature and that the corrosion products consisted of mixed oxides of iron and chromium. It was also found that exposure at the highest temperatures resulted in significant decrease in both tensile strength and ductility. ORNL’s microturbine recuperator test facility, where the exposures were carried out, is also described.

scholarly journals Mechanical properties and corrosion resistance of Mg-RE cast alloys and their plasma electrolytic oxidation

2021 ◽  
Vol 2144 (1) ◽  
pp. 012010
Author(s):  
S V Zasypkin ◽  
A O Cheretaeva ◽  
M R Shafeev ◽  
D L Merson ◽  
M M Krishtal
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Electrolytic Oxidation ◽  
Cast Alloys ◽  
Mechanical Properties And Corrosion ◽  
Plasma Electrolytic ◽  
Cast Magnesium

Abstract The effect of heat treatment on the mechanical properties (hardness, plasticity, yield and tensile strength) and corrosion resistance of several cast magnesium alloys with additions of rare earth metals (Y, Nd and Gd), and their surface modification by plasma electrolytic oxidation (PEO) were investigated. It was found that the heat treatment of the alloys results information of Mg12YZn, Mg3Zn3Y2 and Mg24Y5 based LPSO-phases and causes an increase in hardness and tensile strength by 5-7 and 20-25%, respectively, but at the same time, corrosion resistance of the alloysdrops by 10-20 times. PEO of the alloys after heat treatment reduced the corrosion currents by 1-3 orders of magnitude without changing the corrosion potential.

scholarly journals Effect of Ca Content on the Mechanical Properties and Corrosion Behaviors of Extruded Mg–7Li–3Al Alloys

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1212
Author(s):  
Xiong ◽  
Yang ◽  
Deng ◽  
Li ◽  
Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Corrosion Resistance ◽  
Corrosion Potential ◽  
Tensile Tests ◽  
Extrusion Process ◽  
Ca Addition ◽  
Corrosion Behaviors ◽  
Superior Corrosion Resistance ◽  
Mechanical Properties And Corrosion

The effect of Ca addition on the microstructure, mechanical properties, and corrosion behaviors of the extruded Mg–7Li–3Al alloys was investigated. The results showed that the extruded Mg–7Li–3Al–xCa alloys consisted of α-Mg (hcp) + β-Li (bcc) matrix phases and Al2Ca. With increasing Ca content, the amount and morphology of the Al2Ca phase changed significantly. The grains of the extruded Mg–7Li–3Al–xCa alloys were refined by dynamic recrystallization during the extrusion process. The tensile tests results indicated that the extruded Mg–7Li–3Al–0.4Ca alloy exhibited favorable comprehensive mechanical properties; its ultimate tensile strength was 286 MPa, the yield strength was 249 MPa, and the elongation was 18.7%. The corrosion results showed that this alloy with 0.4 wt.% Ca addition exhibited superior corrosion resistance, with a corrosion potential Ecorr of −1.48742 VVSE, attributed to the formation of protective Al2Ca phases.

Effect of Solution Treatment and Extrusion on the Microstructure and Mechanical Properties of a Mg-2Gd-Nd-0.4Zn-0.3Zr Alloy

2011 ◽  
Vol 197-198 ◽  
pp. 1125-1128 ◽  
Author(s):  
Jing Jiang Nie ◽  
Liang Meng ◽  
Xiu Rong Zhu ◽  
Yong Dong Xu ◽  
Yue Yi Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Treatment Time ◽  
Solution Treatment ◽  
Solution Treated ◽  
Microstructure And Mechanical Properties ◽  
Combined Action ◽  
Strength And Ductility

The effect of the combined action of hot work and heat treatment on the microstructure and mechanical properties of a Mg-2Gd-Nd-0.4Zn-0.3Zr (wt. %) (E21) alloy was investigated. Results showed that the solution treatment time of the ingot played a great effect on the mechanical properties of the extruded alloy. With solution treating time of the ingot increasing, the tensile strength of the extruded alloy decreased gradually, but the elongation increased greatly. The best combination of strength and ductility was achieved for the extruded alloy after the ingot solution treated at 520°C for 3 h, extrusion at 400°C and aging at 200°C for 16 h, namely ultimate tensile strength = 331MPa and elongation = 7.1%.

Characterization of Al-Si-Mg/Al2O3 Nanocomposite Produced by Stir Casting Method

2015 ◽  
Vol 827 ◽  
pp. 294-299 ◽  
Author(s):  
Anne Zulfia ◽  
J. Salahuddin ◽  
Hafeizh E. Ahmad
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Volume Fraction ◽  
Stir Casting ◽  
Nano Particles ◽  
Nano Particle ◽  
Casting Method ◽  
Porosity Level

Al-Si-Mg reinforced with Al2O3 nano particles have been made by stir casting method. The vortex produced by stirrer is to distribute the Al2O3 nano particles in the molten aluminium. The volume fraction of Al2O3 nano particles was varied from 0.5, 1, 2, 3, to 5 Vf%, while the addition of magnesium was 3 Vf% as wetting agent to improve the wettability between Al2O3 nano particle and Al-Si-Mg matrix. The effect of Al2O3 on characteristic of Al-Si-Mg composites was studied. It is found that the presence of Al2O3nano particle led to significant improve in mechanical properties, especially at addition of 0.5 Vf% Al2O3. The ultimate tensile strength reached to 154 MPa with 10.24 % elongation, while the hardness reached to 37.7 HRB followed by decrement in wear rate. The porosity level tend to increase with increasing of Al2O3 and caused decrement in mechanical properties.

Effect of Strontium on Mechanical Properties and Corrosion Resistance of AZ91D

2007 ◽  
Vol 546-549 ◽  
pp. 567-570 ◽  
Author(s):  
Yu Fan ◽  
Guo Hua Wu ◽  
Chun Quan Zhai
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Az91d Alloy ◽  
Nacl Solution ◽  
Strengthening Phase ◽  
Β Phase ◽  
Mg17al12 Phase ◽  
Mechanical Properties And Corrosion

With adding 2% strontium in AZ91D, the ultimate tensile strength and the elongation increased by 10.3% and 55.3%, respectively. This is mainly caused by the refinement of the β phase and the formation of Al4Sr strengthening phase. Furthermore, with adding 2% strontium in AZ91D alloy, the weight loss corrosion rate in 5wt.% NaCl solution decreases to 0.048 mg·cm-2·d-1, which was 33.8 % of the AZ91D corrosion rate. Therefore, the mechanical properties and corrosion resistance of AZ91D could be improved by the addition of 2% strontium, which is due to the refinement of Mg17Al12 phase and the formation of Al4Sr phase.

Improved Heat and Corrosion Resistance of Mg-Al-Zn Alloys by Additions of Minor Alloying Elements

2006 ◽  
Vol 510-511 ◽  
pp. 374-377 ◽  
Author(s):  
Jeong Min Kim ◽  
Bong Koo Park ◽  
Joong Hwan Jun ◽  
Ki Tae Kim ◽  
Woon Jae Jung
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Corrosion Resistance ◽  
Creep Strength ◽  
Alloying Elements ◽  
Rich Phase ◽  
Mechanical Properties And Corrosion ◽  
Zn Alloys ◽  
Apparent Influence

Small amounts of minor alloying elements such as RE and Sr were added to Mg- 8wt%Al-5wt%Zn (AZ91D+4%Zn), and their effects on the microstructure, mechanical properties and corrosion resistance were investigated. The microstucture of the investigated alloys could be characterized by dendritic Mg, Mg17Al12, a quasi-crystalline Zn-rich phase, and Al4RE (if RE is added). Although the tensile strength of alloys was not improved, the creep strength was significantly enhanced by the additions of minor alloying elements. No apparent influence of the additions could be found on the corrosion resistance.

scholarly journals Development and Characterization of New Coating Material of Blended Epoxy-Lacquer with Aluminum

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaoxing Yan ◽  
Yunting Cai ◽  
Rong Lu ◽  
Tetsuo Miyakoshi
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Impact Strength ◽  
Potentiodynamic Polarization ◽  
Mass Fraction ◽  
Electrochemical Impedance ◽  
Mechanical Properties And Corrosion

This study investigated the effects of aluminum (Al) mass fraction on the performance of an epoxy-lacquer based coating. The conductivity increased and IR emissivity and gloss decreased with increased Al mass fraction. When the Al mass fraction was decreased from 40% to 30%, the adhesion and impact strength of epoxy-lacquer based coatings increased and were grade 1 and 50 Kg·cm, respectively. When the Al mass fraction was decreased to 10%, the mechanical properties of epoxy-lacquer based coatings decreased. Potentiodynamic polarization and electrochemical impedance spectroscopy of coatings showed that epoxy-lacquer based coating with 30% Al mass fraction has the best corrosion resistance and the lowest porosity. The epoxy-lacquer based coating with the best stability was that of 30% Al mass fraction. Comparing epoxy-lacquer based coating with polyurethane based coating, the epoxy-lacquer based coating presents not only lower emissivity and gloss but also better mechanical properties and corrosion resistance.

scholarly journals Microstructure and mechanical properties of Mo-Nb microalloyed medium Manganese trip Steel by cyclic quenching

10.30544/426 ◽  
2019 ◽  
Vol 25 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Chunquan Liu ◽  
Qichun Peng ◽  
Zhengliang Xue
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Trip Steel ◽  
Volume Fraction ◽  
Total Elongation ◽  
Reverse Transformation ◽  
Comprehensive Properties ◽  
Cyclic Quenching ◽  
Strength And Ductility

A novel cyclic quenching (CQ) and austenite reverse transformation (ART) was proposed for a Fe-0.25C-3.98Mn-1.22Al-0.20Si-0.19Mo-0.03Nb (wt.%) Mo-Nb microalloyed medium-Mn TRIP steel to improve strength and ductility. The results show that after twice cyclic quenching and ART exhibited optimum comprehensive properties, characterized by an ultimate tensile strength of 838 MPa, a total elongation of 90.8%, a product of strength and elongation (PSE) of 76.1 GPa·%, and the volume fraction of austenite of approximately 62 vol.%.

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