scholarly journals Effects of Co Addition on the Properties and Microstructure of Cu-Ni-Si-P-Mg Alloys

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 368
Author(s):  
Jianyi Cheng ◽  
Fangxin Yu ◽  
Fu Huang
Keyword(s):  
Electrical Conductivity ◽  
Diffusion Rate ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Peak Hardness ◽  
Electronic Industry ◽  
Aging Behavior ◽  
Co Addition ◽  
Lower Diffusion

Cu-Ni-Si alloys are widely used in electrical and electronic industry owing to excellent electrical conductivity and strength. A suitable addition of Co in the Cu-Ni-Si alloys can improve its strength and deteriorate its electrical conductivity. In this work, Cu-Ni-Co-Si-P-Mg alloys with different Co content are employed to investigate the effects of Co on the properties and microstructure. The results showed that Co addition lead to the formation of (Ni, Co)2Si precipitates. (Ni, Co)2Si precipitate is harder to coarsen than δ-Ni2Si during aging. The larger the Co content in the alloys is, the smaller the precipitates formed is. There exists a threshold content of Co to divide the studied alloys into two groups. One group of theses alloys with <1 wt.% Co or Co/Ni ratio <0.56 has the same aging behavior as the Cu-Ni-Si-P-Mg alloy. On the contrary, the time to reach the peak hardness of aging for another group can be obviously delayed and its electrical conductivity decreases slightly with the increase of Co content. It can be attributed to the lower diffusion rate of Co than that of Ni in the Cu matrix. Meanwhile, the Co addition can inhibit the formation of P-enriched Ni-P phase in Co-containing alloys during aging. The as-quenched Cu-1.6Ni-1.2Co-0.65Si-0.1P-0.05Mg alloy can reach 257 HV and 38.7%IACS after aging at 500 °C for 3 h, respectively.

Effect of the Zn/Mg Ratio on Microstructure and Mechanical Properties in Al-Zn-Mg Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 479-482 ◽  
Author(s):  
Masatomo Nishi ◽  
Kenji Matsuda ◽  
Naoya Miura ◽  
Katsumi Watanabe ◽  
Susumu Ikeno ◽  
...  
Keyword(s):  
High Strength ◽  
Hardness Measurement ◽  
Tensile Tests ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Age Hardening ◽  
Peak Hardness ◽  
Number Density ◽  
Peak Aged Condition ◽  
Peak Aged

It is well know that the 7000 series Al-Zn-Mg alloy has good age hardening ability and high strength among commercial aluminum alloys. In this study, hardness measurement, tensile test, SEM and TEM observation have been performed in order to understand the effect of the Zn/Mg ratio on age hardening behaviour in Al-Zn-Mg alloys. It was seen from hardness measurement that the peak hardness increased with increasing amount of Zn and Mg. Tensile tests were performed for the samples of peak aged condition. It was seen that UTS increased with increasing amount of the Zn and Mg. The elongation decreased with increasing the amount of the Zn and Mg. Intregranular fracture was observed in alloys with low amount of Zn and Mg.Transgranular fracture was observed with high amount of Zn and Mg alloy. TEM observation was performed for peak aged samples. The size of precipitates became finer and the number density increased with increasing Zn and Mg contents.T’ Phase and h1 phase were observed in low Zn/Mg alloy. The h’ phase was observed in high Zn/Mg alloy.

scholarly journals Layer-by-Layer Self-Assembly Composite Coatings for Improved Corrosion and Wear Resistance of Mg Alloy for Biomedical Applications

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 515
Author(s):  
Tongfang Liu ◽  
Song Rui ◽  
Sheng Li
Keyword(s):  
Wear Resistance ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Composite Coatings ◽  
Covalent Bond ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Layer By Layer ◽  
Corrosion Propagation ◽  
Chemical Linkage

Mg alloys are promising biomedical metal due to their natural degradability, good processability, and favorable mechanical properties. However, the poor corrosion resistance limits their further clinical applications. In this study, the combined strategies of surface chemical treatment and layer-by-layer self-assembly were used to prepare composite coatings on Mg alloys to improve the biocorrosion resistance. Specially, alkalized AZ91 Mg alloy generated chemical linkage with silane via Si–O–Mg covalent bond at the interface. Subsequently, Si–OH group from silane formed a crosslinked silane layer by Si–O–Si network. Further chemical assembly with graphene oxide (GO), lengthened the diffusion pathway of corrosive medium. The chemically assembled composite coatings could firmly bond to Mg alloy substrate, which persistently and effectively acted as compact barriers against corrosion propagation. Improved biocorrosion resistance of AZ91 Mg alloy with self-assembly composite coatings of silane/GO was subsequently confirmed by immersion tests. Besides, the Mg alloy exhibited good wear resistance due to outside layer of GO with a lubricant effect. Cell viability of higher than 75% had also been found for the alloy with self-assembly composite coatings, which showed good cytocompatibility.

Effect of heating rate on creep aging behavior of Al-Cu-Mg alloy

2017 ◽  
Vol 688 ◽  
pp. 488-497 ◽  
Author(s):  
Yongqian Xu ◽  
Lihua Zhan ◽  
Ziyao Ma ◽  
Minghui Huang ◽  
Kai Wang ◽  
...  
Keyword(s):  
Heating Rate ◽  
Mg Alloy ◽  
Aging Behavior

Friction Stir Welding of Dissimilar Formed Mg Alloys (AZ31/AZ91)

2005 ◽  
Vol 486-487 ◽  
pp. 249-252 ◽  
Author(s):  
Chang Yong Lee ◽  
Won Bae Lee ◽  
Yun Mo Yeon ◽  
Seung Boo Jung
Keyword(s):  
Friction Stir Welding ◽  
Dynamic Recrystallization ◽  
Tensile Test ◽  
Intermetallic Compounds ◽  
Grain Growth ◽  
Weld Zone ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Friction Stir ◽  
Az31 Mg Alloy

Friction stir welding of dissimilar formed Mg alloys(AZ31/AZ91) was successfully carried out at the limited welding conditions. In a sound joint, SZ was mainly consisted of AZ31 Mg alloy which was located the retreating side. Dynamic recrystallization and grain growth occurred and β intermetallic compounds of AZ 91 Mg alloy was not observed in SZ. BM had a higher hardness than that of the weld zone. The fracture location was not weld zone but BM of the AZ91 Mg alloy in tensile test.

scholarly journals Influence of the Chemical Composition on Electrical Conductivity and Mechanical Properties of the Hypoeutectic Al-Si-Mg Alloys

2016 ◽  
Vol 61 (1) ◽  
pp. 353-360 ◽  
Author(s):  
B. Dybowski ◽  
J. Szymszal ◽  
Ł. Poloczek ◽  
A. Kiełbus
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Chemical Composition ◽  
Aluminium Alloys ◽  
Mg Alloys ◽  
High Electrical Conductivity ◽  
Transportation Industry ◽  
Proper Selection ◽  
Ti Addition ◽  
Selection Of

Due to low density and good mechanical properties, aluminium alloys are widely applied in transportation industry. Moreover, they are characterized by the specific physical properties, such as high electrical conductivity. This led to application of the hypoeutectic Al-Si-Mg alloys in the power generation industry. Proper selection of the alloys chemical composition is an important stage in achievement of the demanded properties. The following paper presents results of the research on the influence of alloys chemical composition on their properties. It has been revealed that Si and Ti addition decreases electrical conductivity of the Al-Si-Mg alloys, while Na addition increases it. The mechanical properties of the investigated alloys are decreased by both silicon and iron presence. Sodium addition increases ductility of the Al-Si-Mg alloys.

Aging behavior of the extruded SiCp-reinforced AZ91 Mg alloy composite

2018 ◽  
Vol 34 (2) ◽  
pp. 335-343
Author(s):  
Hai Chang ◽  
Xiaoshi Hu ◽  
Xiaojun Wang ◽  
Junfeng Du ◽  
Libo Tong
Keyword(s):  
Mg Alloy ◽  
Alloy Composite ◽  
Aging Behavior ◽  
Image Position

Abstract

Corrosion Resistance of Mg Alloy with High Zn Concentration Including Impurity Cu

2021 ◽  
Vol 1016 ◽  
pp. 592-597
Author(s):  
Masato Ikoma ◽  
Taiki Morishige ◽  
Tetsuo Kikuchi ◽  
Ryuichi Yoshida ◽  
Toshihide Takenaka
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Second Phase ◽  
Transportation Industry ◽  
Primary Metal ◽  
Cu Content ◽  
Zn Concentration ◽  
Lower Corrosion Rate

Mg alloys are very attractive materials for transportation industry due to their toughness and lightness. Recycling Mg alloys is desired for energy saving that otherwise would be required to produce its primary metal. However, secondary produced Mg tends to contain a few impurity elements that deteriorate its corrosion resistance. For example, contamination of Mg alloy by Cu induces second phase of Mg2Cu and it works as strong cathode, resulting in the corrosion rate rapidly increasing. It was previously reported that the corrosion resistance of Mg with impurity Cu was remarkably improved by addition of alloying element Zn. Addition of Zn into Mg formed MgZn2 phase and incorporated Cu into MgZn2 phase instead of Mg2Cu formation. In this way, since Zn serves to improve the corrosion resistance of Mg, Mg alloy with high Zn concentration may form a lot of MgZn2 and may have better corrosion resistance even with high Cu concentration. In this work, the corrosion behavior of Mg-6mass%-1mass%Al (ZA61) with different Cu content up to 1mass% was investigated. As a result, ZA61-1.0Cu had much lower corrosion rate compared to Mg-0.2%Cu and the corrosion rate was almost the same as that of pure Mg.

Regression Modeling and Experimental Investigations on Ageing Behavior of Nano-Fly Ash Reinforced Al-10wt%Mg Alloy Matrix Composites

2018 ◽  
Vol 6 (2) ◽  
pp. 36-49
Author(s):  
Srinivasa Prasad Katrenipadu ◽  
Swami Naidu Gurugubelli
Keyword(s):  
Fly Ash ◽  
Regression Model ◽  
Weight Fraction ◽  
Stir Casting ◽  
Mg Alloy ◽  
Peak Hardness ◽  
Experimental Investigations ◽  
Matrix Composites ◽  
Casting Method ◽  
Alloy Matrix

Nano-fly ash particles reinforced Al-10wt%Mg alloy matrix composites produced by stir-casting method were tested for their ageing response. Ageing studies were performed at 160 °C, 200 °C and 240 °C temperatures and a maximum peak hardness of 142 VHN was observed during ageing at 200 °C for the composite with 10 wt% nano fly ash reinforcement. This is due to rapid nucleation and growth of βI particles at this temperature. Experiments were designed for different compositions and different ageing temperatures on the basis of the Design of Experiments technique. The factorial design is considered to improve the reliability of results and to reduce the size of experimentation without loss of accuracy. A model to predict the ageing behaviour of the composites was developed with the terms of 5, 10 and 15% weight fraction of fly ash at 160 °C, 200 °C and 240 °C ageing temperatures. The developed regression model was validated by statistical software MINITAB-R17.1.0. It was found that the developed regression model could be effectively used to predict the ageing behavior at 95% confidence level.

scholarly journals Effect of Al Content in the Mg-Based Alloys on the Composition and Corrosion Resistance of Composite Hydroxide Films Formed by Steam Coating

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1188 ◽  
Author(s):  
Takahiro Ishizaki ◽  
Tomohiro Miyashita ◽  
Momo Inamura ◽  
Yuma Nagashima ◽  
Ai Serizawa
Keyword(s):  
Aqueous Solution ◽  
Corrosion Resistance ◽  
Treatment Time ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Potential Range ◽  
Protective Film ◽  
Al Content ◽  
Passive Behavior ◽  
Superior Corrosion Resistance

Mg alloys are expected to be used in fields of the transportation industry because of their lightweight property, however, they show low corrosion resistance. To improve the corrosion resistance, preparation of the protective film on Mg alloys is essential. In this study, composite hydroxide films were prepared on three types of Mg alloys with different aluminum contents—that is, AZ31, AZ61, and AZ91D—by steam coating to investigate the relationship between the Mg-Al layered double hydroxide (LDH) content in the film and the Al content in the Mg alloys. Scanning electron microscopy (SEM) observation demonstrated that films were formed densely on all Mg alloy surfaces. X-ray diffraction (XRD) analyses revealed that all films prepared on AZ61 and AZ91D were composed of Mg(OH)2, AlOOH, and Mg-Al LDH, while the film containing Mg(OH)2 and Mg-Al LDH were formed only on AZ31. The Mg-Al LDH content in the film prepared on AZ61 was relatively higher than those prepared on AZ31 and AZ91D. The content of AlOOH in the film increased with an increase in the Al content in the Mg alloys. The film thickness changed depending on the treatment time and type of Mg alloy. Polarization curve measurements in 5 mass% NaCl solution demonstrated that the film prepared on the AZ61 showed complete passive behavior within the potential range of −1.0 to −0.64 V. In addition, immersion tests in 5 mass% NaCl aqueous solution for 480 h demonstrated that the film on the AZ61 had superior durability against 5 mass% NaCl aqueous solution. These results indicated that the film on the AZ61 had the most superior corrosion resistance among all samples. The results obtained in this study suggest that the LDH content in the film could be related to the corrosion resistance of the film.

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