Special issue "Magnesium and magnesium alloys". Evaluation of corrosion resistance by salt spray test on the die casting AZ91 magnesium alloys with paint finishing.

1992 ◽  
Vol 42 (12) ◽  
pp. 784-789 ◽  
Author(s):  
Matsufumi TAKAYA ◽  
Tetsuzi ITOH ◽  
Hiroyuki UMEHARA
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloys ◽  
Die Casting ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Special Issue ◽  
Az91 Magnesium

scholarly journals Ultrasonic Sensors-Assisted Corrosion Studies on Surface Coated AlSi9Cu3 Alloy Die Castings

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Yuh-Chung Hu ◽  
Senthil Kumaran Selvaraj ◽  
Manivannan Subramanian ◽  
Kathiravan Srinivasan ◽  
Srinivasan Narayanan
Keyword(s):  
Corrosion Resistance ◽  
Die Casting ◽  
Pure Aluminum ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Al Alloy ◽  
Neutral Salt ◽  
Powder Coatings ◽  
Acrylic Paint ◽  
Epoxy Primer

A novel phenomenon known as Industry X.0 is becoming extremely popular for digitizing and reinventing business organizations through the adaption of rapid and dynamic technological, innovational, and organizational changes for attaining the profitable revenue. This work investigates the die-casted commercially pure aluminum alloyed with 9% silicon and 3% copper (AlSi9Cu3) that is produced through the gravity die casting process. Further, the degradation of surface coating on die-casted AlSi9Cu3 alloy was explored. The acrylic paint electrodeposition (ED) coat, 2-coat polyester without primer and 3-coat polyester with epoxy primer powder coatings were used in this study. Moreover, the 3.5 wt.% of sodium chloride (3.5 wt.% of NaCl) test solution was used for electrochemical and salt spray test and the tools used to assess electrochemical properties were electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and neutral salt spray test (NSS). The microstructure of AlSi9Cu3 after corrosion exposure was investigated; also, the microstructure of coated and uncoated AlSi9Cu3 samples was analyzed by SEM microscopy after corrosion exposure. Besides, the electrochemical studies were also carried out on the Al alloy die casting. It was found that acrylic paint ED coatings exhibited higher corrosion resistance than 2-coat polyester without primer & 3-coat polyester with epoxy primer powder coatings. Acrylic paint ED coating showed higher corrosion resistance in AC and a lower value in DC and 3-coat polyester with epoxy primer powder coating displayed higher corrosion resistance in DC and a lower value in AC.

scholarly journals Corrosion resistance of the die casting AZ91D magnesium alloys with paint finishing.

1998 ◽  
Vol 48 (5) ◽  
pp. 248-255 ◽  
Author(s):  
Hiroyuki UMEHARA ◽  
Matsufumi TAKAYA ◽  
Tetsuji ITOH
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloys ◽  
Die Casting

Effects of Erbium Addition on the Corrosion Resistance and Microstructure of AZ91 Magnesium Alloy

2011 ◽  
Vol 194-196 ◽  
pp. 1221-1224 ◽  
Author(s):  
Zhong Jun Wang ◽  
Yang Xu ◽  
Jing Zhu
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Discontinuous Precipitation ◽  
Az91 Magnesium Alloy ◽  
Continuous Precipitation ◽  
Az91 Magnesium ◽  
Precipitation Phase

The microstructures and corrosion resistance of AZ91 and AZ91+0.5 wt.% erbium (Er) magnesium alloys were studied, respectively. The results show that the Er addition in scrap AZ91 magnesium alloy can improve the corrosion resistance, markedly. The discontinuous precipitation phase (DPP) for Mg17Al12was retarded and the amount of DPP was decreased by 41% due to the formation of Al8ErMn4phase during solidification. The amount of continuous precipitation phase (CPP) in grains was decreased by 8% because of the formation of Al7ErMn5phase during solidification.

Corrosion and Protection of Magnesium Alloys

2015 ◽  
Vol 1120-1121 ◽  
pp. 1078-1082 ◽  
Author(s):  
Yang Yang Lv ◽  
Ling Feng Zhang
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Automotive Industry ◽  
Physical And Mechanical Properties ◽  
Current Status ◽  
Strain Rates ◽  
Metallic Materials ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium

Magnesium alloy as a green material in the 21st century, because of its excellent physical and mechanical properties of metallic materials as an ideal in the automotive industry, electronic industry and aviation, aerospace and other industries[1]. However, poor corrosion resistance of magnesium alloys become an important issue hinder application of magnesium alloys[2]. So magnesium alloy corrosion problems and the current status of research paper reviews several magnesium alloy protection methods at home and abroad, and also highlighted with our latest laser shock (LSP) study of AZ91 magnesium alloy at high strain rates of corrosion resistance results.

Research on Heavy-Duty Coating Protection System of Magnesium Alloy

2015 ◽  
Vol 1119 ◽  
pp. 525-528
Author(s):  
Ru Tang Yan ◽  
Yuan Yuan Li ◽  
Chun Wei She ◽  
Hua Geng Li ◽  
Hua Pan Li
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Protection System ◽  
Test Time ◽  
Test Results ◽  
Ageing Test ◽  
Micro Arc Oxidation ◽  
Resistance Performance

The poor corrosion resistance of magnesium alloys become the bottleneck restricting its development. Based on micro-arc oxidation (MAO) technology and the characteristics of fluorocarbon coating the surface of magnesium alloy build a high corrosion protection system, namely: Based on micro-arc oxidation coating fluorocarbon coatings. The formation of the composite coating through the resistance to ageing test through the resistance to ageing test, acid and alkali experiment and salt spray test results show the excellent corrosion resistance performance. Among them, the resistance to salt spray test time can reach 1500 h, which breaks the bottleneck of magnesium alloy corrosion resistance of 1000 h.

scholarly journals RESISTÊNCIA A CORROSÃO EM DIFERENTES TRATAMENTOS DE SUPERFÍCIE SOBRE LIGAS DE ZINCO UTILIZADOS EM METAIS SANITÁRIOS

2019 ◽  
Vol 10 (2) ◽  
pp. 185
Author(s):  
Suzan Arnold ◽  
Sandra Raquel Kunst ◽  
Luciane Taís Fuhr ◽  
Cláudia Trindade Oliveira
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Lower Cost ◽  
Salt Spray ◽  
Aggressive Medium ◽  
Salt Spray Test ◽  
High Porosity ◽  
Ferrous Alloys ◽  
Copper Nickel

Entre as ligas não ferrosas, as ligas de zamac são as mais utilizadas para a fundição e vêm sendo aplicadas na substituição de peças de latão, utilizadas industrialmente em metais sanitários. O zamac apresenta propriedades mecânicas semelhantes às do latão, porém com custo inferior. Entretanto, a alta porosidade destas ligas, impede que tratamentos superficiais garantam bom acabamento e resistência à corrosão. Visando melhorar o desempenho, frente à corrosão de peças de zamac, o objetivo do presente trabalho é avaliar o processo de diferentes tratamentos de superfície dos metais sanitários produzidos em zamac. As amostras foram injetadas sobre pressão e submetidas a diferentes tratamentos superficiais (tratamento mecânico, tratamento químico, cobre alcalino, cobre ácido, níquel, cromo). Os corpos de prova foram expostos a um meio agressivo, por meio de nevoa salina a fim de analisar a resistência à corrosão das peças, além de análises de polarização, metalografia e microdureza. Observou-se que a maior incidência de corrosão ocorreu nas partes de injeção e solda da peça, as amostras tratadas com níquel e cromo demonstraram o melhor desemprenho frente a resistência a corrosão.Palavras-chave: Zamac. Metais sanitários. Corrosão.ABSTRACTAmong the non ferrous alloys, zamak are the most used for casting and have been applied to substitute brass parts, industrially utilized in sanitary metals. The zamak presents mechanical properties similar to brass, however with lower cost. Meanwhile, the high porosity of these alloys hinders the superficial treatments ensure good finishing and corrosion resistance. Aiming to improve the performance against corrosion of zamak parts, this work evaluates the process of different superficial treatments of sanitary metals produced with zamak. The samples were injected under pressure and submitted to different superficial treatments (mechanical, chemical, alkaline copper, acid copper, nickel and chromium). The specimens were exposed to an aggressive medium through salt spray test to evaluate the corrosion resistance, and the following analysis: polarization, metallography and microhardness. It was observed that the higher corrosion incidence occurred on the injection and weld regions. The samples treated with nickel and chromium demonstrated better performance of corrosion resistance. Keywords: Zamak. Sanitary materials. Corrosion.

scholarly journals Improvement of AZ91 Alloy Corrosion Properties by Duplex NI-P Coating Deposition

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1357 ◽  
Author(s):  
Jaromír Wasserbauer ◽  
Martin Buchtík ◽  
Jakub Tkacz ◽  
Stanislava Fintová ◽  
Jozef Minda ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Az91 Alloy ◽  
Neutral Salt ◽  
Az91 Magnesium Alloy ◽  
Corrosion Properties ◽  
Az91 Magnesium

The corrosion behavior of duplex Ni-P coatings deposited on AZ91 magnesium alloy was studied. The electroless deposition process of duplex Ni-P coating consisted in the preparation of low-phosphorus Ni-P coating (5.7 wt.% of P), which served as a bond coating and high-phosphorus Ni-P coating (11.5 wt.% of P) deposited on it. The duplex Ni-P coatings with the thickness of 25, 50, 75 and 100 µm were deposited on AZ91 magnesium alloy. The electrochemical corrosion behavior of coated AZ91 magnesium alloy was investigated by electrochemical impedance spectroscopy and potentiodynamic polarization method in 0.1 M NaCl. Obtained results showed a significant improvement in the corrosion resistance of coated specimens when compared to uncoated AZ91 magnesium alloy. From the results of the immersion tests in 3.5 wt.% NaCl, 10% solution of HCl and NaOH and 5% neutral salt spray, a noticeable increase in the corrosion resistance with the increasing thickness of the Ni-P coating was observed.

Two-Step Anodization of AZ91 Magnesium Alloy

2005 ◽  
Vol 488-489 ◽  
pp. 653-656 ◽  
Author(s):  
Rong Fa Zhang ◽  
Da Yong Shan ◽  
En Hou Han
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Salt Spray ◽  
Az91 Magnesium Alloy ◽  
Anodic Coating ◽  
Excellent Corrosion Resistance ◽  
Long Time ◽  
Az91 Magnesium ◽  
Short Time ◽  
Salt Spray Testing

Among four AZ91 samples, two were once anodized and the others were twice anodized in two electrolytic baths. After twice anodization, two coatings coexist on the base metal. Surface morphology showed that for one of twice anodic coatings (sample 2), the second coating only existed on some places and sealed some pores of the first coating after short time on the second anodizing. However, for another twice anodic coating (namely sample 4), the second anodization spent very long time and the coating was thick and loose. Salt spray testing showed that sample 2 had the most excellent corrosion resistance and the reason is discussed.

Effects of Calcium-Containing Electrolytes on Anodic Coatings Formed on AZ91 Magnesium Alloys

2014 ◽  
Vol 952 ◽  
pp. 43-46
Author(s):  
Shu Fang Zhang ◽  
Rong Fa Zhang ◽  
Biao Qu ◽  
Yin Feng Zheng
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloys ◽  
Calcium Content ◽  
Coating Properties ◽  
Calcium Salts ◽  
Calcium Addition ◽  
Az91 Magnesium

Anodic coatings were prepared by micro-arc on AZ91 magnesium alloys in solutions with different calcium salts. The influence of calcium salts on the coating properties were studied. The result shows that anodic coatings formed in Ca (OH)2system has higher calcium content. When the Ca (OH)2concentrations is 2g/L, the Ca content is the highest, and the Calcium addition achieve the best corrosion resistance.

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