Effect of Phase Fraction Ratio Between Al3Mg2 and Mg2Si on the Oxidation Behavior of Al–Mg–Si Alloys

2021 ◽  
Vol 16 (7) ◽  
pp. 1047-1051
Author(s):  
Seong-Ho Ha ◽  
Abdul Wahid Shah ◽  
Bong-Hwan Kim ◽  
Young-Ok Yoon ◽  
Hyun-Kyu Lim ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
High Temperatures ◽  
Cross Sections ◽  
Oxidation Behavior ◽  
Eutectic Phase ◽  
Mg Alloy ◽  
Phase Fraction ◽  
The Matrix ◽  
Si Content

The effect of the phase fraction ratio between Al3Mg2 and Mg2Si on the oxidation resistance of Al–Mg–Si alloys at high temperatures was investigated. With addition of 1 mass%Si in Al-6 mass%Mg alloy, the as-cast microstructures showed formation of Mg2Si phase by eutectic reactions. With increasing Si content more than 3 mass%, the Mg2Si and Si are formed as eutectic phases with no β-Al3Mg2 phase. In addition, with an increase in the Si content from 3 mass%, significantly refined as-cast microstructures and distribution of extended eutectic phase areas were observed. The oxidized cross-sections of Al-6 mass%Mg and Al-6 mass%Mg-1 mass%Si alloys showed coarse and dark areas, which are considered as oxide clusters, nonuniformly grown into the matrix. However, Al-6 mass%Mg-3 mass%Si and Al-6 mass%Mg-5 mass%Si alloys had no significantly grown oxide clusters on the surfaces. Based on the results, it was concluded that the reduction of the ratio between β-Al3Mg2 and Mg2Si phases can reduce the rapid oxidation of Mg.

The Effect of Protective Coatings on the Oxidation Behavior of 6061Al/SiC Composite at High Temperatures

2011 ◽  
Vol 383-390 ◽  
pp. 3949-3953
Author(s):  
N.K. Udayashankar ◽  
S. Rajasekaran ◽  
Jagannath Nayak
Keyword(s):  
Composite Material ◽  
Grain Boundary ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Oxidation Behavior ◽  
Low Voltage ◽  
Protective Coatings ◽  
Measurement Techniques ◽  
Aluminum Coating ◽  
The Matrix

This paper analyses the effect of protective coatings on the oxidation behavior of 6061Al/SiC composite material at temperatures ranging from 500 to 800 K. Aluminum and AlCrN coatings are employed as protective coatings in order to improve the oxidation resistance of the composite. SEM, EDAX, XRD and oxidation measurement techniques are used to study the oxidation behavior and to characterize the composite specimens. Oxidation of the composite material without protective coatings is seen to be very rapid during the initial stages of exposure to the high temperatures but subsequently slowed down due to the formation of a protective surface layer of oxide. The oxidation was especially severe above 600 K. The interface between the matrix and reinforcement particles and the grain boundary regions of intermetallic precipitates in the matrix enhance this oxidation process since they provided sites for oxidation initiation. Aluminum coating on the composite obtained by DC magnetron sputtering technique and AlCrN coating obtained by low voltage electron beam evaporation technique reduce the oxidation rate effectively since the interface regions between the matrix and reinforcement, grain boundary regions of the matrix are unexposed to the atmosphere. Aluminum coating provides better oxidation resistance for 6061 Al/SiC composites.

The Effect of Aging and the Protective Coating on the Oxidation Behavior of 6061Al/SiC Composite at High Temperatures

2011 ◽  
Vol 462-463 ◽  
pp. 30-35
Author(s):  
S. Rajasekaran ◽  
N.K. Udayashankar ◽  
Jagannath Nayak
Keyword(s):  
Composite Material ◽  
Grain Boundary ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Protective Coating ◽  
Oxidation Behavior ◽  
Protective Coatings ◽  
Measurement Techniques ◽  
Aluminum Coating ◽  
The Matrix

This paper analyses the effect of ageing on the oxidation behavior of 6061Al/SiC composite material at temperatures ranging from 500 to 800 K. Also aluminum coating is employed as protective coating in order to improve the oxidation resistance of the composite. SEM, EDAX, XRD and stepped oxidation measurement techniques are used to study the oxidation behavior and to characterize the composite specimens. Oxidation of the composite material without protective coatings is seen to be very rapid during the initial stages of exposure to the high temperatures but subsequently slowed down due to the formation of a protective surface layer of oxide. Among the artificially aged composites, peak aged specimens are more prone to oxidation. The oxidation was especially severe above 600 K. The interface between the matrix and reinforcement particles and the grain boundary regions of the matrix enhance this oxidation process since they provided sites for oxidation initiation. Aluminum coating on the composite obtained by DC magnetron sputtering technique, reduce the oxidation rate effectively since the interface regions between the matrix and reinforcement, grain boundary regions of the matrix are unexposed to the atmosphere. Aluminum coating provides better oxidation resistance for the artificially aged composites.

Oxidation of (Al+8%Mn)3Ti Intermetallics Synthesized by Mechanical Alloying

2004 ◽  
Vol 449-452 ◽  
pp. 825-828
Author(s):  
Y.D. Jang ◽  
Sung Jin Kim ◽  
Dong Bok Lee
Keyword(s):  
Mechanical Alloying ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Barrier Layer ◽  
Oxidation Behavior ◽  
Cold Isostatic Pressing ◽  
Isostatic Pressing ◽  
Ti Alloys ◽  
Dissolved Ions

The oxidation behavior of (Al+8 at.%Mn)3Ti alloys prepared by mechanical alloying followed by cold isostatic pressing and sintering at high temperatures was investigated at 1000 and 1100°C up to 300 hr in air. Since the Al2O3 barrier layer having some dissolved ions of Ti, and Mn formed, the oxidation resistance of the prepared alloys was excellent.

Effects of Si Content on the Oxidation Behavior of Fe–Si Alloys in Air

2011 ◽  
Vol 696 ◽  
pp. 126-131 ◽  
Author(s):  
Takumi Nishimoto ◽  
Kazuhiko Honda ◽  
Yasumitsu Kondo ◽  
Kenichi Uemura
Keyword(s):  
Oxide Scale ◽  
Cross Sections ◽  
Oxidation Kinetics ◽  
Oxidation Behavior ◽  
Elemental Distribution ◽  
Oxide Scales ◽  
Scale Thickness ◽  
Internal Oxidation Zone ◽  
Diffusion Controlled ◽  
Si Content

The oxidation behavior of Fe–Si alloys at 1073K in air was investigated. The oxidation kinetics described by the parabolic rate law of diffusion controlled oxidation and the oxidation rate decrease with the increasing Si content. Fe-Si alloys were oxidized for different times at 1073K to obtain the same scale thickness of approximately 30μm. Observations of scale cross-sections indicated the structure of oxide scale and elemental distribution in oxide scales strongly depends on Si content. The oxide scale on Fe-Si alloys with low Si content consisted of three layers with an outer Fe2O3, an intermediate Fe3O4 and an inner FeO and some voids were formed in Fe3O4 and FeO layers. The Si-rich oxide layer was formed at the scale/alloy interface of Fe-Si alloys with high Si content. Furthermore, the amount of internal oxidation zone increased with the increasing Si content. Observations of scale cross-sections indicated that the structure of oxide scale and elemental distribution in oxide scale strongly depend on Si content.

The Study on Oxidation Resistance Properties of Ductile Cast Irons for Exhaust Manifold at High Temperatures

2010 ◽  
Vol 97-101 ◽  
pp. 530-533 ◽  
Author(s):  
Yun Long Yang ◽  
Zhan Yi Cao ◽  
Yang Qi ◽  
Yong Bing Liu
Keyword(s):  
Cast Iron ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Oxidation Behavior ◽  
Exhaust Manifold ◽  
Cast Irons ◽  
Comparison And Analysis ◽  
Better Than

The oxidation behavior of two ductile cast irons was investigated in this paper. The alloys were a high Si-Mo ductile and a ductile Ni-Resist cast iron which were developed by FAW Foundry. Polished sections were exposed at temperatures between 800 °C and 1000 °C, mostly for 80h. It has been found that the property of oxidation resistance of ductile Ni-Resist cast iron is excellent or better than that of high Si-Mo ductile by comparison and analysis.

HIGH TEMPERATURE OXIDATION OF CaB6-28wt%Ni SINTERED BODY

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1166-1171 ◽  
Author(s):  
LIN ZHANG ◽  
GUANGHUI MIN ◽  
LIXIA YANG ◽  
HUASHUN YU
Keyword(s):  
Cross Sections ◽  
Oxidation Behavior ◽  
Oxidation Process ◽  
Bulk Material ◽  
Element Distribution ◽  
Sintered Body ◽  
Temperature Oxidation ◽  
Sintering Aid ◽  
Calcium Hexaboride ◽  
The Matrix

The oxidation process of calcium hexaboride ( CaB 6) ceramic sintered body with 28wt% nickel as a sintering aid was investigated systematically in this paper. DTA-TG was used to analyze the oxidation behavior at various temperatures. The morphologies of the oxidation surfaces and the interface between the oxide layer and the bulk material were given by EPMA and BSE, respectively. Element distribution on cross-sections was measured by an energy spectrum analyzer. It is found that CaB 6-28 wt % Ni shows an excellent oxidation resistance below 1173K owing to the protection provided by calcium borate on the surface. Catastrophic fast oxidation begins at 1273K. The grain boundaries act as the diffusion channels for O 2 penetration. The existence of Ni doesn't affect the oxidation behavior of the matrix CaB 6. The mechanism of oxidation was also discussed in this paper.

Comparison of Oxidation Behavior of Binary Co-10X (x=Al, Si, Cr) Alloys at 973 and 1073K

2013 ◽  
Vol 395-396 ◽  
pp. 238-242 ◽  
Author(s):  
Hong Hua Zhang ◽  
Jun Huai Xiang ◽  
Xian Chao Xu ◽  
Chu Wang
Keyword(s):  
Oxidation Resistance ◽  
High Temperatures ◽  
Growth Process ◽  
Oxidation Behavior ◽  
Schematic Model ◽  
Scale Growth ◽  
Protective Properties

Kinetics and products of oxidation behavior of binary Co-10Al, Co-10Si and Co-10Cr alloys at 0.1Mpa oxygen at 973 and 1073K were analyzed and compared. The investigations show that CoO doesn't provide protective properties at high temperatures. Among the three alloy components, Co-10Cr has better oxidation resistance at 973K, while Co-10Al has at 1073K, and the causes are given. In addition, the schematic model of scale growth process is presented.

scholarly journals Mechanical Properties and Oxidation Behavior of Cr–Si–N Coatings

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 528 ◽  
Author(s):  
Li-Chun Chang ◽  
Yu-Heng Liu ◽  
Yung-I Chen
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Young's Modulus ◽  
Elastic Recovery ◽  
Columnar Structure ◽  
Flow Ratio ◽  
Nanocomposite Structure ◽  
Si Content

Cr–Si–N coatings were prepared through reactive direct current magneton sputtering using a high N2/Ar flow ratio of 1. The addition of Si to improve the mechanical properties and oxidation resistance of Cr–N coatings was examined. The results indicated that the Cr–Si–N coatings with an Si content of <12 at % and an N content of >50 at % exhibited a cubic CrN phase with a columnar structure, whereas the coatings with 14 at % Si comprised of a nanocomposite structure, and the coatings with 16–18 at % Si were near-amorphous. The nanocomposite Cr32Si14N54 coating possessed hardness and Young’s modulus values of 17 and 209 GPa, respectively, accompanied with a hardness to effective Young’s modulus (H/E*) value of 0.077 and an elastic recovery (We) level of 55%—all the properties were highest within the as-deposited coating. The addition of Si was also beneficial to reduce the surface roughness and improve the oxidation resistance.

scholarly journals The Oxidation Resistance of Nb-Si-Based Alloys at Intermediate and High Temperatures

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1229 ◽  
Author(s):  
Jianyong Yang ◽  
Guanqun Zhuo ◽  
Kaiyong Jiang ◽  
Xinghan Zhu ◽  
Linfen Su
Keyword(s):  
Oxidation Resistance ◽  
High Temperatures ◽  
Oxidation Behavior ◽  
Short Time ◽  
Oxidation Mechanisms

The oxidation behavior of three Nb-Si-based alloys were evaluated at intermediate (800 °C) and high (1250 °C) temperatures for 100 h in air. At 800 °C, the Nb-24Ti-15Si-13Cr-2Al-2Hf (at. %) alloy suffered from catastrophic pest oxidation. This pest phenomenon was suppressed by the addition of Sn. However, Ta addition protected the Nb-Si-based alloys from pest oxidation for a short time. At 1250 °C, Sn could enhance the oxidation resistance of Nb-Si-based alloys due to the formation of a Sn-rich layer. In addition, the oxidation mechanisms of Nb-Si-based alloys at intermediate and high temperatures were discussed.

Effects of Rare Earth Metal Ce Additions on the 1150°C Isothermal Oxidation Behavior of Ni-20Cr Alloy

2013 ◽  
Vol 771 ◽  
pp. 23-27
Author(s):  
Hong Qiang Nan ◽  
Jin Shan Li ◽  
Rui Hu ◽  
Liang Yuan ◽  
Hong Chao Kou ◽  
...  
Keyword(s):  
Rare Earth ◽  
Oxidation Resistance ◽  
Cross Section ◽  
Rare Earth Metal ◽  
Oxidation Behavior ◽  
Earth Metal ◽  
Isothermal Oxidation ◽  
Oxide Scales ◽  
The Matrix ◽  
Micro Analysis

Isothermal oxidation behavior was investigated for Ni-20Cr alloy with addition of different Ce 0 (wt)%, 0.042(wt)% and 0.094(wt)% at 1150°C for 100h.The surface and cross-section microstructures of the oxide scales were analyzed by EPMA(Eelectron Probe Micro-Analysis). The addition of Ce in Ni-20Cr alloy may improved the cohesion between the matrix and the oxide scales significantly and increased the oxidation resistance of Ni-20Cr alloy. Compared with 0 (wt)%Ce and 0.042(wt)% Ce in Ni-20Cr alloys, the oxide scales on Ni-20Cr alloy with addition of 0.094(wt)% Ce showed compact, which limited the internal oxidation.The cross-section microstructure of oxide scales presented three complicated oxide layers, which were Cr2O3, SiO2and Al2O3from the oxide scales to the matrix.

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