The Effect of Additional Elements on Oxide Scale Evolution of Fe-20at.%Cr-10at.%Al Alloy at 900 °C in Air

2008 ◽  
Vol 595-598 ◽  
pp. 1013-1021 ◽  
Author(s):  
Yuri Kitajima ◽  
Shigenari Hayashi ◽  
Shigeharu Ukai ◽  
Toshio Narita
Keyword(s):  
Growth Behavior ◽  
Al Alloys ◽  
Al Alloy ◽  
Al2o3 Scale ◽  
Scale Spallation ◽  
Additional Element ◽  
Outward Diffusion ◽  
Fecral Alloy ◽  
Element Addition ◽  
Scale Evolution

The oxidation behavior of Fe-20at.%Cr-10at.%Al alloys with a small amount of an additional element such as W, Cu, Mn, Nb, Mo, Re, Co or Ti was investigated at 900 °C for up to 625hr. The fourth element addition to the FeCrAl alloy could be classified into two groups; elements (Mn, Nb, Ti) that are contained in the Al2O3 scale, and elements (W, Mo, Re, Co) which are not present in the scale. In the latter case, the elements (W, Cu) caused scale spallation. The rumpling of alloys with Mn, Nb or Ti was smaller than that of the other alloys. The surface of the alloy with Ti was the smooth. Pt marker experiments suggested that the Al2O3 scale formed on the alloy with Ti grew by inward diffusion of O, whilst the Al2O3 scale formed on the FeCrAl alloy grew by both outward diffusion of Al and inward diffusion of O. This different growth behavior due to the elements incorporated in the Al2O3 scale could have an effect on the surface rumpling behavior.

Influence of ageing treatment on microstructure, mechanical properties and adhesive wear behaviour of 6063 aluminium alloy

2014 ◽  
Vol 66 (4) ◽  
pp. 520-524 ◽  
Author(s):  
Serkan Büyükdoğan ◽  
Süleyman Gündüz ◽  
Mustafa Türkmen
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
High Speed ◽  
Al Alloys ◽  
Wear Behaviour ◽  
Al Alloy ◽  
Strain Ageing ◽  
Content Type ◽  
Static Strain ◽  
Structural Applications

Purpose – The paper aims to provide new observations about static strain ageing in aluminium (Al) alloys which are widely used in structural applications. Design/methodology/approach – The present work aims to provide theoretical and practical information to industries or researchers who may be interested in the effect of static strain ageing on mechanical properties of Al alloys. The data are sorted into the following sections: introduction, materials and experimental procedure, results and discussion and conclusions. Findings – Tensile strength, proof strength (0.2 per cent) and percentage elongation measurement were used to investigate the effect of strain ageing on the mechanical properties. Wear tests were performed by sliding the pin specimens, which were prepared from as-received, solution heat-treated, deformed and undeformed specimens after ageing, on high-speed tool steel (64 HRC). It is concluded that the variations in ageing time improved the strength and wear resistance of the 6063 Al alloy; however, a plastically deformed solution-treated alloy has higher strength and wear resistance than undeformed specimens for different ageing times at 180°C. Practical implications – A very useful source of information for industries using or planning to produce Al alloys. Originality/value – This paper fulfils an identified resource need and offers practical help to the industries.

Direct Cladding from Molten Metals of Aluminum and Magnesium Alloys Using a Tandem Horizontal Twin Roll Caster

2015 ◽  
Vol 772 ◽  
pp. 250-256 ◽  
Author(s):  
Hideto Harada ◽  
Shin Ichi Nishida ◽  
Mayumi Suzuki ◽  
Hisaki Watari ◽  
T. Haga
Keyword(s):  
Surface Condition ◽  
Hardness Test ◽  
Al Alloys ◽  
Mg Alloy ◽  
Al Alloy ◽  
Molten Metals ◽  
Electron Probe Micro Analyzer ◽  
Twin Roll Caster ◽  
Aluminum And Magnesium Alloys ◽  
Twin Roll

This paper describes direct cladding of magnesium (Mg) and aluminum (Al) alloys using a tandem horizontal twin roll caster that has three pairs of upper and lower rolls. Manufacturing conditions that are appropriate for fabricating Al/Mg and Al/Mg/Al cladded material were investigated. The surface condition of the cladded cast strip was examined. An electron probe micro analyzer was used to observe the interface between Al alloy and Mg alloy. The thickness of the mixed layer of Al and Mg alloy was 15μm, and how the materials were connected was clarified. Microscopic observation and backscattered electron analysis were used to investigate the cladding mechanisms of the Al and Mg alloy layers. Average hardness was determined using the Vickers hardness test at the Al layer and at the diffused layer between Mg and Al alloys. Cladding of Al/Mg alloy and A/Mg/Al alloy was possible using a tandem twin-roll caster. In addition, Al3Mg2 and Al12Mg17 phase precipitation at the interface of the Al and Mg alloys was confirmed during direct cladding from molten metals.

Effects of the Duration of Potentiostatic Anodizing on the Corrosion Resistance and Surface Morphology of Films Formed on Mg-Al Alloys

2005 ◽  
Vol 486-487 ◽  
pp. 125-128 ◽  
Author(s):  
Seong Jong Kim ◽  
Seok Ki Jang ◽  
Jeong Il Kim
Keyword(s):  
Corrosion Resistance ◽  
Surface Morphology ◽  
Anodic Oxide ◽  
Al Alloys ◽  
Anodic Film ◽  
Al Alloy ◽  
Active Dissolution ◽  
Dissolution Reaction ◽  
Alloy Az91 ◽  
Morphology Of Films

The effects of the duration of potentiostatic anodizing on the corrosion resistance and surface morphology of anodic oxide films formed on Mg-Al alloy (AZ91) in 1 M NaOH were investigated. With the formation of an anodic film, the current density decreased gradually, started to stabilize at 300 s, and was relatively constant at 600 s. These results may be related to the increased time for catalysis of the active dissolution reaction, which not only enlarges the area covered by the anodic film, but also produces a more coherent, thicker film. The reference corrosion potentials of the anodic oxide film for AZ91 shifted in the noble direction with time. In general, the corrosion resistance characteristics were improved with anodizing time.

scholarly journals Influence of Pre-Stress Magnitude on Fatigue Crack Growth Behavior of Al-Alloy

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1267
Author(s):  
Chunguo Zhang ◽  
Weizhen Song ◽  
Qitao Wang ◽  
Wen Liu
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Shot Peening ◽  
Fatigue Property ◽  
Growth Behavior ◽  
Crack Growth Behavior ◽  
Al Alloy ◽  
Fatigue Crack Growth Behavior

From tensile overload to shot peening, there have been many attempts to extend the fatigue properties of metals. A key challenge with the cold work processes is that it is hard to avoid generation of harmful effects (e.g., the increase of surface roughness caused by shot peening). Pre-stress has a positive effect on improving the fatigue property of metals, and it is expected to strength Al-alloy without introducing adverse factors. Four pre-stresses ranged from 120 to 183 MPa were incorporated in four cracked extended-compact tension specimens by application of different load based on the measured stress–strain curve. Fatigue crack growth behavior and fractured characteristic of the pre-stressed specimens were investigated systematically and were compared with those of an as-received specimen. The results show that the pre-stress ranged from 120 to 183 MPa significantly improved the fatigue resistance of Al-alloy by comparison with that of the as-received specimen. With increasing pre-stress, the fatigue life first increases, then decrease, and the specimen with pre-stress of 158 MPa has the longest fatigue life. For the manner of pre-stress, no adverse factor was observed for increasing fatigue property, and the induced pre-stress reduced gradually till to disappear during subsequent fatigue cycling.

Effect of double-sided friction stir welding on the mechanical and microstructural characteristics of AA5754 aluminium alloy

2021 ◽  
Vol 63 (9) ◽  
pp. 829-835
Author(s):  
Sare Çelik ◽  
Fatmagül Tolun
Keyword(s):  
Friction Stir Welding ◽  
Al Alloys ◽  
Fusion Welding ◽  
Welding Parameters ◽  
Al Alloy ◽  
Test Results ◽  
Feeding Rates ◽  
Microstructural Characteristics ◽  
Friction Stir ◽  
Tool Tilt Angle

Abstract AA5754Al alloy is widely used in industry. However, as in the case of all Al alloys, the 5xxx series Al alloys cannot be easily joined through fusion welding techniques. To address this problem, in this study, the effect of double-sided friction stir welding at various tool rotational speeds (450, 710, and 900 rpm), feeding rates (40, 50, and 80 mm × min-1), and tool tilt angles (0°, 1°, 2°) on the welding parameters and mechanical and microstructural characteristics of AA5754 Al alloy was determined. Tensile strength tests and microhardness tests were performed to examine the mechanical properties of the welded specimens. The microstructures of the welded zone were examined by obtaining optical microscopy and scanning electron microscopy images. The tensile test results indicated that the specimens exhibited the highest welding performance of 95.17 % at a tool rotational speed, feed rate, and tool tilt angle of 450 rpm, 50 mm × min-1 and 1°, respectively.

Effect of Voltage on Mg-Li-Al Alloy Anodic Oxide Film

2018 ◽  
Vol 941 ◽  
pp. 1194-1197 ◽  
Author(s):  
Naoya Miyakita ◽  
Natsuki Tanigaki ◽  
Taiki Morishige ◽  
Toshihide Takenaka
Keyword(s):  
Oxide Film ◽  
Phosphoric Acid ◽  
Anodic Oxidation ◽  
Surface Coating ◽  
Low Voltage ◽  
Active Surface ◽  
Anodic Oxide ◽  
Al Alloys ◽  
Anodic Oxide Film ◽  
Al Alloy

Anodic oxidation of Mg-Li-Al alloys using phosphoric acid-based bath were processed to obtain the corrosion-proof surface coating. The specimen oxidized at low voltage anodically dissolved without the formation of oxidized film. Anodic oxidation film could be formed at higher voltage due to thin layer preferentially formed on tthe active surface, this layer develops to stable thick film. There were no significant differences in film thickness between LA141 and LA143 alloys.

Dynamic Compaction of Al Alloys

1983 ◽  
Vol 28 ◽  
Author(s):  
J.W. Sears ◽  
B.C. Muddle ◽  
H.L. Fraser
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Transmission Electron Microscopy ◽  
Al Alloys ◽  
Dynamic Compaction ◽  
Al Alloy ◽  
Analytical Transmission Electron Microscopy ◽  
Projectile Velocity ◽  
Transmission Electron

ABSTRACTPowders of Al alloy 7091 have been consolidated by means of dynamic compaction. The dependence of density and hardness on projectile velocity has been determined. The resulting as-compacted material has been characterized using analytical transmission electron microscopy and evidence of interparticle melting observed. The microstructural responseof the compacted material to heat treatment at 523 and 723°K has been investigated.

Wear Resistance of Pre-ECAP Annealing A356 Al Alloy with 1.5 Wt.% TiB2

2019 ◽  
Vol 961 ◽  
pp. 118-125
Author(s):  
Muhammad Syukron ◽  
Zuhailawati Hussein ◽  
Abu Seman Anasyida
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Resistance ◽  
Optical Microscopy ◽  
Al Alloys ◽  
Wear Testing ◽  
Al Alloy ◽  
Hardness Distribution ◽  
Grain Refiner ◽  
Ecap Processing

The combination of heat treatment, addition of grain refiner and ECAP processing is used to improve mechanical properties and wear resistance of A356 Al alloys with 1.5 wt.% TiB2. The alloys were grouped into as-cast and pre-ECAP annealing. The alloys were characterized with hardness and wear testing, optical microscopy and SEM. The ECAP processing was done through BA route for 4 passes and it improved hardness, distribution of TiB2 and Si particles in the aluminium matrix and increased wear resitance of pre-ECAP annealing specimen.

Arc Fusion Welding of Mg-Al2Ca-Added Al 5xxx Alloys

2017 ◽  
Vol 371 ◽  
pp. 25-30
Author(s):  
Min Jung Kang ◽  
Cheol Hee Kim
Keyword(s):  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Al Alloys ◽  
Fusion Welding ◽  
Al Alloy ◽  
Alloy Specimen ◽  
Metallurgical Properties ◽  
Metal Arc Welding ◽  
Al 5052 Alloy

When casting ECO Al alloys, Mg-Al2Ca is used as a substitute for elemental Mg during the alloying process. Several previous studies have determined the mechanical and metallurgical properties of the ECO Al 5052 alloy. In this study, the weldability of the ECO Al 5052 alloy was determined. Gas metal arc welding was performed, and the resultant mechanical and metallurgical aspects of the welds in ECO Al 5052 alloy and commercial Al 5052 alloy were examined. In comparison to the commercial Al 5052 alloy specimen, the welds produced in the ECO Al 5052 alloy exhibited a very narrow heat-affected zone and were not softened through grain coarsening. Consequently, almost 100% joint efficiencies were observed in ECO Al alloy welds, in comparison to joint efficiencies of only 82% in conventional Al 5052 alloy welds.

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