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"Magnesium (Mg) alloys are receiving increasing attention due to their abundance, light weight, castability, formability, mechanical properties and corrosion performance. By selecting the appropriate combination of materials, coatings and surface modifications, their corrosion resistance can be greatly enhanced. Corrosion prevention of magnesium alloys is a comprehensive guide to the effective prevention of corrosion in these important light metals.Part one discusses alloying, inhibition and prevention strategies for magnesium alloys as well as corrosion and prevention principles. Part two reviews surface treatment and conversion. Beginning with an overview of surface cleaning and pre-conditioning, the book goes on to discuss the use of surface processing and alloying, laser treatments, chemical conversion and electrochemical anodization to improve the corrosion resistance of magnesium alloys. Coatings are then the focus of part three, including varied plating techniques, cold spray coatings, gel and electroless electrophoresis coatings. Finally, the book concludes in part four with a selection of case studies investigating the application of preventative techniques for both automotive and medical applications."

"Designed for use by practicing engineers, and maintenance and operating personnel, who are concerned with the problem of corrosion of aluminum in their daily job functions. DLC: Aluminum--Corrosion."

"Magnesium dan paduannya termasuk sebagai logam struktural teringan dengan ketahanan korosi yang paling rentan diantara logam struktural lainya. Lapisan MgO dibentuk pada permukaan paduan magnesium dengan proses anodisasi dalam larutan NaOH 3M untuk meningkatkan ketahanan korosi. Variasi tegangan (10 V, 15 V, 20 V) dan waktu (5 menit, 10 menit, 15 menit) dilakukan pada proses anodisasi untuk mengetahui hubungannya dengan laju korosi. Perubahan morfologi dan struktur lapisan oksida diamati dengan menggunakan mikroskop optik dan scanning electron microscope (SEM). Fasa lapisan oksida pada paduan magnesium diamati dengan menggunakan X-ray diffraction (XRD).

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Magnesium and its alloys is the lightest of all structural metal with the most vulnerable corrosion resistance among other structural metal. MgO layer is formed on the surface of magnesium alloy with anodizing process in NaOH 3M solution to increase the corrosion resistance. Voltage variation (10 V, 15 V, 20V) and time variation (5 minutes, 10 minutes, and 15 minutes) is being done in anodization process to determine its relation with corrosion rate. Changes in morphology and structure of oxide layer is being observed with optik microscope and scanning electron microscope (SEM). The phase of oxide layer in magnesium alloy is being observed with X-ray Diffraction (XRD).

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"Tantangan dalam pengembangan implant permanen tulang dan gigi berbasis titanium (Ti) adalah meminimalisir unsur paduan yang bersifat toxic. Paduan yang saat ini paling banyak digunakan secara klinis adalah Ti-6Al-4V. Unsur Al and V bersifat toxic dan berpotensi menimbulkan reaksi alergi. Untuk mengatasi masalah tersebut, dikembangkan paduan metastabil β-Ti yang memiliki sifat non-alergi, modulus elastisitas rendah, dan ketahanan korosi yang baik. Dalam penelitian ini, paduan metastabil TiNbSn difabrikasi dengan metode arc melting dengan variasi konsentrasi Sn 2, 5 dan 8 wt%. Remelting dilakukan sebanyak 5x untuk mendistribusikan unsur dalam paduan secara merata. Selanjutnya paduan diberi perlakuan solution treatment pada suhu 1000°C selama 6 jam. Pengaruh konsentrasi Sn terhadap mikrostruktur, sifat mekanik, dan sifat korosi diteliti masing-masing menggunakan mikroskop elektron, uji hardness dan modulus, dan uji elektrokimia. Analisis XRD menunjukkan bahwa paduan TiNb memiliki dua fasa yaitu β dan α. Fasa α berkurang dengan penambahan konsentrasi Sn dalam paduan. Selain itu, ukuran butir logam paduan TiNb dengan rata-rata 256 µm membesar seiring dengan kenaikan konsentrasi Sn dalam paduan menjadi 446, 379, dan 384 µm. Berkurangnya fasa α dan perbesaran ukuran butir menyebabkan turunnya nilai kekerasan dan modulus elastisitas paduan. Paduan TiNb memiliki kekerasan 292,6 HV yang kemudian turun menjadi 254,8; 267,0; 266,6 HV dengan penambahan Sn masing-masing 2, 5 dan 8 wt%. Nilai modulus elastisitasn TiNb sebesar 121.4 GPa turun drastic menjadi 95.4; 108.2; dan 103.8 GPa pada paduan yang mengandung Sn 2, 5, dan 8 wt%. Uji potensial korosi bebas, open circuit potential (OCP), menunjukkan penurunan nilai OCP dengan bertambahnya konsentrasi Sn dalam paduan. Uji polarisasi potensiodinamik menunjukkan penurunan drastis nilai potensial korosi TiNb dari -0,28 VAg/AgCl menjadi -0,52 dan -0,44 VAg/AgCl dengan penambahan 2 dan 8 wt% Sn dalam paduan. Namun, penambahan 5 wt% Sn relatif tidak merubah nilai potensial korosi paduan TiNb. Hal yang sama diperoleh pada uji electrochemical impedance spectroscopy (EIS) yang menunjukkan nilai kurva impedansi yang sama antara TiNb dan TiNb-5Sn dibandingkan dengan TiNb-2Sn dan TiNb-8Sn yang menunjukkan penurunan impendansi secara signifikan.

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The challenge in developing titanium-based (Ti) permanent bone and tooth implants is to minimize toxic elements of the alloy. The alloy that is currently most widely used clinically is Ti-6Al-4V. Al and V elements are toxic and have the potential to cause allergic reactions. To overcome this problem, metastable β-Ti alloys were developed which have non-allergic properties, low elastic modulus, and good corrosion resistance. In this study, TiNbSn metastable alloys were fabricated using the arc melting method with variations in Sn 2, 5 and 8 wt% concentrations. Remelting is done as much as 5 times to distribute the elements in the alloy evenly. Furthermore, the alloy was solution treated at a temperature of 1000 ° C for 6 hours. The effect of Sn concentrations on microstructure, mechanical properties, and corrosion properties were studied using electron microscopy, hardness and modulus tests, and electrochemical tests respectively. XRD analysis shows that TiNb alloys have two phases namely Î and α. The α phase decreases with the addition of the Sn concentration in the alloy. In addition, the grain size of TiNb alloy metal with an average of 256 µm enlarged along with the increase in Sn in alloy concentration to 446, 379, and 384 µm. Reduced α phase and enlargement of grain size caused a decrease in hardness value and elastic modulus of alloy. TiNb alloy has a hardness of 292.6 HV which then drops to 254.8; 267.0; 266.6 HV with the addition of Sn each of 2, 5 and 8 wt%. The elastic modulus of TiNb was 121.4 GPa which dropped dramatically to 95.4; 108.2; and 103.8 GPa on alloys containing Sn 2, 5 and 8 wt%. Free corrosion potential test, open circuit potential (OCP), shows a decrease in OCP value with increasing concentration of Sn in alloy. Potentiodynamic polarization test showed a drastic decrease in the value of TiNb corrosion potential from -0.28 VAg / AgCl to -0.52 and -0.44 VAg / AgCl with the addition of 2 and 8 wt% Sn in the alloy. However, the addition of 5 wt% Sn relative did not change the value of the TiNb alloy corrosion potential. The same was obtained from the electrochemical impedance spectroscopy (EIS) test which showed the same impedance curve value between TiNb and TiNb-5Sn compared to TiNb-2Sn and TiNb-8Sn which showed a significant decrease in impedance. "

"The characteristics of coatings formed by Plasma Electrolytic Oxidation (PEO) are affected by the composition of metal substrates. In this work, the effect of alloying element Ca (0, 1 and 2 wt%) on the degradation behavior and apatite-forming ability of PEO coated AZ61 magnesium alloys was clarified by means of polarization measurements in 0.9% NaCl solution and an in-vitro test in Simulated Body Fluid (SBF), respectively. The AZ61 alloys were subjected to plasma electrolytic oxidation at a constant current of 200 A/m2 at 25°C for 8 min in 0.5 M Na3PO4 solution. The surface investigation suggested no significant effect of Ca content on the morphology of the PEO coating formed on the AZ61 specimens. The coatings exhibited an eruption-like structure decorated with micropores and microcracks. Their average thicknesses were 13.2, 17.4 and 14.3 µm for AZ61, AZ61-1Ca and AZ61-2Ca, respectively. The polarization measurements showed no significant difference in the corrosion potentials (-1.60 VAg/AgCl) and corrosion current densities (1.61×10-5 A cm-2) of all the coated specimens. Similarly, there was no significant effect of Ca on the apatite-forming ability in SBF, as indicated by the lack of apatite deposition on all the coated specimens after 14 days of immersion. Further sealing of the PEO coatings by chemical treatment in NaOH solution is suggested to enhance the corrosion resistance."

"Reinforced concrete structure are subjected to damage and deterioration during their service life because of exposure to many types of environmental influence. These damages or deterioration can reduce the performance and intended function of the structure. On several occasions structural failures are closely linked to the corrosion of steel reinforcement in concrete."