Strengthening of iron aluminide alloys for high-temperature applications

2004 ◽  
Vol 842 ◽  
Author(s):  
Martin Palm ◽  
André Schneider ◽  
Frank Stein ◽  
Gerhard Sauthoff
Keyword(s):  
High Temperature ◽  
Corrosion Behaviour ◽  
Intermetallic Phase ◽  
High Temperature Corrosion ◽  
Iron Aluminide ◽  
Max Planck ◽  
High Temperature Alloys ◽  
Structural Applications ◽  
Ordered Intermetallic ◽  
Temperature Applications

ABSTRACTAn overview is given on materials developments of ferritic and Fe3Al-based iron aluminium alloys with strengthening precipitate phases for high-temperature applications currently underway at the Max-Planck-Institut für Eisenforschung GmbH (MPIE). The development of high-temperature alloys for structural applications is to be focussed on optimisation of strength, creep and corrosion resistance at high temperatures and sufficient ductility at lower temperatures. This is discussed with respect to recent studies on Fe-Al-based alloys with strengthening precipitates, such as κ-phase Fe3AlCx, MC-carbides, Laves phase, and the B2-ordered intermetallic phase NiAl. The following alloy systems have been investigated: Fe-Al-X (X=C, Ti, Ta, Mo, Zr), Fe-Al-Ti-Nb, Fe-Al-Ni-Cr, and Fe-Al-M-C (M=Ti, V, Nb, Ta).The investigations have been focussed on the microstructure, constitution, mechanical properties, and high-temperature corrosion behaviour of Fe-Al-based alloys with Al contents ranging from 10 to 30 at. %.

Corrosion Behaviour of Ti-48Al-2Nb-2Cr Alloys

2012 ◽  
Vol 323-325 ◽  
pp. 301-307
Author(s):  
B. Pelic ◽  
D. Rafaja ◽  
Patrick J. Masset ◽  
H.J. Seifert ◽  
L. Bortolotto ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Protective Coatings ◽  
Corrosion Behaviour ◽  
Base Material ◽  
High Temperature Corrosion ◽  
Al Alloy ◽  
Environmental Embrittlement ◽  
Structural Applications

γ-TiAl intermetallics are attractive materials for high-temperature structural applications in the aerospace and automobile industries. However, they show environmental embrittlement at elevated temperatures that is mainly related to their low high-temperature corrosion resistance. One way how to improve the high-temperature corrosion resistance is the deposition of protective coatings on the surface of the base material. In this study, samples of a Ti-Al alloy with the chemical composition Ti-48Al-2Cr-2Nb (at.%) were covered by physically vapour deposited (PVD), by metalorganic chemically vapour deposited (MOCVD) and by high-velocity oxy-fuel (HVOF) sprayed coatings. All coatings were based on the Ti-Al alloys and contained different amounts of alloying elements. The corrosion experiments were performed in molten salts containing 75 wt.% Na2SO4and 25 wt.% NaCl at 850°C up to 336 h. Both, PVD and CVD protected coatings reduced the changes in the mass of the samples over the corrosion time. Still, the formation of TiO2could not be avoided, as it was confirmed by glancing-angle X-ray diffraction experiments.

Electrochemical Studies on High-Temperature Corrosion of Silicon-Iron Coatings and Iron Aluminide Intermetallic Alloys by Molten Salts

CORROSION ◽  
2001 ◽  
Vol 57 (6) ◽  
pp. 489-496 ◽  
Author(s):  
M. Amaya ◽  
J. Porcayo-Calderon ◽  
L. Martinez
Keyword(s):  
High Temperature ◽  
Molten Salt ◽  
Electric Power ◽  
Molten Salts ◽  
Corrosion Current ◽  
High Temperature Corrosion ◽  
Iron Aluminide ◽  
Fuel Oil ◽  
Silicon Iron ◽  
Salt Corrosion

Abstract The performance of Fe-Si coatings and an iron aluminide (FeAl) intermetallic alloy (FeAl40at%+0.1at%B+10vol%Al2O3) in molten salts containing vanadium pentoxide (V2O5) and sodium sulfate (Na2SO4) is reported. Corrosion and fouling by ash deposits containing V2O5 and Na2SO4 are typical corrosion problems in fuel oil-fired electric power units. High-temperature corrosion tests were performed using both electrochemical polarization and immersion techniques. The temperature interval of this study was 600°C to 900°C, and the molten salts were 80wt%V2O5-20wt%Na2SO4. Curves of corrosion current density vs temperature obtained by the potentiodynamic studies are reported, as well as the weight loss vs temperature curves from molten salt immersion tests. Both Fe-Si coatings and FeAl40at%+0.1at%B+10vol%Al2O3 showed good behavior against molten salt corrosion. The final results show the potential of these coatings and alloys to solve the high-temperature corrosion in fuel oil-fired electric power units.

High-temperature corrosion behaviour of plasma sprayed Gd2SrAl2O7 coatings by V2O5 at 700-1200ºC

2021 ◽  
pp. 110032
Author(s):  
Jieyan Yuan ◽  
Shujuan Dong ◽  
Jianing Jiang ◽  
Longhui Deng ◽  
Xueqiang Cao
Keyword(s):  
High Temperature ◽  
Corrosion Behaviour ◽  
High Temperature Corrosion ◽  
Plasma Sprayed

High temperature corrosion behaviour of aluminised FC 25 cast iron using pack cementation

2019 ◽  
Vol 66 (2) ◽  
pp. 236-241 ◽  
Author(s):  
Somrerk Chandra-Ambhorn ◽  
Neramit Krasaelom ◽  
Tummaporn Thublaor ◽  
Sirichai Leelachao
Keyword(s):  
Cast Iron ◽  
High Temperature ◽  
Corrosion Behaviour ◽  
Mass Gain ◽  
High Temperature Corrosion ◽  
Pack Cementation ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
Seat Insert

Purpose This study aims to apply the pack cementation to develop the Fe-Al layers on the surface of FC 25 cast iron in order to increase the high-temperature corrosion resistance of the alloy. Design/methodology/approach Pack cementation was applied on the surface of FC 25 cast iron at 1,050°C. The bare and aluminised alloys were subjected to the oxidation test in 20 per cent O2-N2 at 850 °C. Scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD) were used for characterisation. Findings The layers of pack cementation consisted of Fe2Al5, FeAl2 and FeAl, and solid solution alloyed with Al. The oxidation kinetics of the bare cast iron was parabolic. Mass gain of the aluminised cast iron was significantly decreased compared with that of the bare cast iron. This was because of the protective alumina formation on the aluminised alloy surface. Al in the Fe–Al layer also tended to be homogenised during oxidation. Originality/value Even though the aluminising of alloys was extensively studied, the application of that process to the FC 25 cast iron grade was originally developed in this work. The significantly reduced mass gain of the aluminised FC 25 cast iron makes the studied alloy be promising for the use as a valve seat insert in an agricultural single-cylinder four-stroke engine, which might be run by using a relatively cheaper fuel, i.e. LPG, but as a consequence requires the higher oxidation resistance of the engine parts.

High temperature corrosion behaviour of nickel aluminides

1999 ◽  
Vol 7 (10) ◽  
pp. 1183-1194 ◽  
Author(s):  
J. Klöwer ◽  
U. Brill ◽  
U. Heubner
Keyword(s):  
High Temperature ◽  
Corrosion Behaviour ◽  
High Temperature Corrosion ◽  
Nickel Aluminides

Kinetics of Corrosion Processes of Alloy on the Intermetallic Phase Matrix FeAl in High Temperature in Air Atmosphere

2013 ◽  
Vol 212 ◽  
pp. 137-140 ◽  
Author(s):  
Janusz Cebulski ◽  
Stanisław Lalik
Keyword(s):  
High Temperature ◽  
Heat Resistance ◽  
High Temperatures ◽  
Intermetallic Phase ◽  
High Temperature Corrosion ◽  
Corrosion Products ◽  
Corrosion Tests ◽  
Air Atmosphere ◽  
Passive Oxides ◽  
Kinetics Of

The aim of this paper was to determine the resistance to high-temperature corrosion in atmosphere of air for alloy Fe-40Al-5Cr-0.2Ti-0.2B. Corrosion tests were conducted in temperatures from 600 to 900°C in time from 2 to 64 hours. Conducted tests have shown a slight increase of weight of samples in periods of time which followed. Increase of weight is connected with corrosion products in the form of passive oxides which form on the surface of the alloy. Kinetics of corrosion processes has parabolic course in tested temperature range which proves the formation of passive layers of corrosion products on the surface of samples. Heat resistance of the alloy on intermetallic phase matrix FeAl brings about potential possibilities to apply this alloy as a material meant for work in elevated and high temperatures in the environment which includes oxygen.

Sign in / Sign up

Export Citation Format

Share Document