Ex Situ Tribological and Electro-chemical analysis of Aluminium

Aluminium sample coupon is evaluated for electro-chemical, tribological and microstructural study under selected test conditions. Aluminium is a light-weight material chiefly preferred in fields like automobile, aerospace, marine and satellite domestic appliances etc. Moreover, due to its specific characteristics, it plays a crucial role in industries and research fields. In the present work, the ex situ tribological (wear test), electrochemical (corrosion test), mechanical (microhardness test) and microstructural (nodularity percentage) behaviours of Aluminum sample is presaged. The test results reveal that, when experiment advance, with respect to time the wear rate increases, frictional force is decreased and pin temperature increased. The corrosion test is held on specimen coupon in two modes, before and after wear test, and observed that the corrosion rate gets improved on specimen after wear test. Nodularity analysis also express that the nodularity percentage is increased by 5%. Before wear test, the percentage of accepted count to total count of nodules on texture is 65.18%, while the percentage after wear test is found to be 70.29%. The Vickers Microhardness analysis exhibits the hardness value as 160 HV on Vickers Hardness Scale.

Corrosion Susceptibility of Stainless Steel in Artificial Saliva Containing Citric Acid

ObjectivesThe aims of this study are to investigate the effect of concentration of citric acid in saliva environment on SS 316L and effect of ginger and garlic on SS 316L corrosion in citric acid-containing saliva environment.Methods.Seven SS 316L specimen of dimensions 1cm × 1cm were used for this study. The specimen were subjected to electrochemical corrosion test using an in artificial saliva containing citric acid with varying concentrations of 0.0 g/l, 3.0 g/l, 6.0 g/l, and 9.0 g/l electrochemical cell. 10 g/l each of garlic and ginger were also added to two of artificial saliva samples containing citric acid and one sample of artificial saliva contained 5 g/l of ginger and 5 g/l of garlic added together so as to study the corrosion effects of these substances on the SS 316L specimen in saliva environment. The results were displayed based on Tafel’s plot of current density against potential difference. Also, corrosion rates of the samples were determined and presented in graphical form.Results.The study results showed that citric acid is a good inhibitor of corrosion of SS 316L dental implant in oral environment with its inhibition efficiency depending on its concentration, and that the mechanism of this inhibition can attributed to the adsorption of citric acid onto the metal alloy (SS 316L) surface. The study also concluded that both ginger and garlic are promoters of corrosion of SS 316L alloy implants in saliva environment.

Metallurgical and Corrosion Property of Additive Manufactured Titanium Alloy-Ti6Al4V

Additive manufacturing (AM) is an important manufacturing technology that has changed the way products are designed and manufactured. Laser Metal Deposition (LMD), an AM technology, has the capability of producing components using a 3-Dimensional CAD model, through a layer by layer formation process just like any other AM technology. In this study, the influence of the scanning speed on the corrosion property of Titanium alloy-Ti6Al4V using LMD process was investigated. The scanning speed varied between 0.02 m/s and 0.14 m/s while other processing parameters were kept constant. The electrochemical corrosion test was conducted in sodium chloride (NaCl) solution. The result revealed that the corrosion resistance property was found to increase with the scanning speed.

Corrosion Behavior of AZ91 Mg-Alloy Coated with AlN and TiN in NaCl and Hank's Solution

Magnesium alloys create increasing interest in structural application where weight reduction is vast concern. However, its low corrosion resistance especially in atmosphere environment restricts their wide application. In this study, AlN and TiN were coated on AZ91 Mg alloy using PVD magnetron sputtering. AlN and TiN existence is confirmed via grazing angle x-ray diffraction (GA-XRD). The corrosion behaviors of uncoated and coated AZ91 Mg alloy in3.5% NaCl and Hanks solutions were investigated using a potentiostat during electrochemical corrosion test. AlN and TiN coated samples showed better performance in Hanks solution with TiN coated samples have the least corrosion rate (penetration rate=0.040mm/yr and mass loss rate=0.191g/m2d) in Hanks solution. These create interest to further works on exploring the potential of coated AZ91 Mg alloy in biomaterial application.

Apparent Inversion of the Effect of Alloyed Molybdenum for Corrosion of Ordinary and Enhanced 316L Stainless Steel in Sulfuric Acid

An aging assessment of the OPG waste resin storage system predicted the potential for premature failure of the carbon steel resin liners. Consequently, resin liners made of 316L stainless steel with a minimum content of 2.5% molybdenum were selected to replace the carbon steel liners. The 2.5% Mo 316L stainless steel was specified to enhance pitting resistance in the spent resin environment. With the additional Mo, one would expect that a brief electrochemical corrosion test will reveal the superiority of such alloy over conventional 316L steel. This study reports a contrary experience