The impact of urban rain on the changes of bare and artificially patinated bronze during 9-year exposure.

Atmospheric pollutants in the air form acid rain which interacts with bronze surfaces exposed in urban outdoor environment. In this study, different types of patinas on bronze were investigated during and after 9 years of exposure to urban environment in moderately polluted continental city. Natural bronze patina and artificial brown sulphide, green chloride, and green-blue nitrate patinas were investigated.

The microstructure, mechanical and electrochemical properties of 3D printed alloys with reusing powders.

CoCrMo and Ti6Al4V are widely used in medical, dental and 3D printing technology, allowing the accurate fabrication of geometrically complicated structures. In order to reduce the costs of printed objects, the reuse of powder is common daily practice. When using 3D printing technology, the direct impact of elevated temperatures and the influence of the laser beam may change the properties of the powder when it is reused, thus affecting the final properties of the printed object.

A Critical Appraisal of the Use and Properties of Nickel-Titanium Dental Alloys.

Nickel-titanium (NiTi) archwires are used in dentistry for orthodontic treatment. NiTi alloys have favourable mechanical characteristics, such as superelasticity and shape memory, and are also known as a corrosion-resistant alloy. In specific cases, an archwire could be attacked by certain types of corrosion or wear degradation, which can cause the leaching of metal ions and a hypersensitive response due to increased concentrations of Ni in the human body.

Characterizing Steel Corrosion in Different Alkali-Activated Mortars.

Alkali-activated materials (AAMs) present a promising potential alternative to ordinary Portland cement (OPC). The service life of reinforced concrete structures depends greatly on the corrosion resistance of the steel used for reinforcement. Due to the wide range and diverse properties of AAMs, the corrosion processes of steel in these materials is still relatively unknown.

Influence of the Deep Cryogenic Treatment on AISI 52100 and AISI D3 Steel's Corrosion Resistance.

The effect of deep cryogenic treatment (DCT) on corrosion resistance of steels AISI 52100 and AISI D3 is investigated and compared with conventional heat-treated counterparts. DCT's influence on microstructural changes is subsequently correlated to the corrosion resistance. DCT is confirmed to reduce the formation of corrosion products on steels' surface, retard the corrosion products development and propagation.

An Electrochemical and Spectroscopic Study of Surfaces on Bronze Sculptures Exposed to Urban Environment.

Polluted urban environment enhances dissolution of patina and underlying bronze material of recent and historical bronze sculptures exposed outdoors. In this work, two bronze statues, situated in one of the most polluted Croatian cities, were examined in order to characterize composition of patina and its electrochemical stability. The composition of patina on several positions on each sculpture was determined by EDS, Raman spectroscopy, and FTIR measurements.

Comparison Between Accuracy of Posts Fabricated Using a Digital CAD/CAM Technique and a Conventional Direct Technique.

Purpose: To compare the accuracy of posts fabricated using a conventional direct technique with casting to the accuracy of posts fabricated using a fully digital protocol with CAD/CAM technology and selective laser melting.

Materials And Methods: Ten extracted permanent maxillary incisors were endodontically treated and prepared for a post. For each tooth, two metal posts were fabricated, one by casting (Group C) and one by a fully digital protocol (Group D).

Sensor Development for Corrosion Monitoring of Stainless Steels in HSO Solutions.

Equipment made of different stainless steels is often used in the hydrometallurgical processing industry. In this study, an electrical resistance sensor was developed for monitoring corrosion in acidic solutions at high temperature. Two types of stainless steel were used as the electrode materials, namely grade 316L stainless steel (EN 1.

Manipulation of TiO Nanoparticle/Polymer Coatings Wettability and Friction in Different Environments.

An AISI 316L surface was functionalized by the adsorption of hydrophilic epoxy and epoxy/TiO/epoxy coatings and hydrophobic epoxy/fluoroalkylsilanefunctionalized FASTiO/epoxy coatings. We characterized the coatings' wettability, morphology and average surface roughness and discussed the influence of surface wettability and morphology on the coefficient of friction and the wear resistance. Experiments were performed in dry, distilled water and in a simulated physiological solution (Hank's solution).

Monitoring the Corrosion of Steel in Concrete Exposed to a Marine Environment.

Reinforced concrete structures require continuous monitoring and maintenance to prevent corrosion of the carbon steel reinforcement. In this work, concrete columns with carbon and stainless steel reinforcements were exposed to a real marine environment. In order to monitor the corrosion processes, two types of corrosion probes were embedded in these columns at different height levels.

Activation and Repassivation of Stainless Steels in Artificial Brines as a Function of pH.

When planning oil wells with stainless steel components, two possible reasons for depassivation have to be considered-chemical depassivation caused by acidizing jobs and mechanical depassivation caused by various tools and hard particles. The study explores conditions causing chemical activation of investigated steels and circumstances under which repassivation occurs after activation. The main focus of the study is to determine, how quickly various steels can repassivate under different conditions and to find pH values where repassivation will occur after depassivation.

Development of an Electrical Resistance Sensor from High Strength Steel for Automotive Applications.

This work focuses on a demonstration of the monitoring of corrosion processes taking place in high strength steel in automotive applications. This is performed by means of a corrosion sensor, which operates as an electrical resistance sensor. It was developed from the same type of material that is used for the high-strength steel parts produced in the automotive industry.

The effect of pH, fluoride and tribocorrosion on the surface properties of dental archwires.

Nickel-titanium and stainless steel are the most commonly used alloys for orthodontic treatments. Even though both are known to be resistant to corrosion, there are circumstances that can lead to undesired situations, like localized types of corrosion attack, wear during sliding of an archwire though brackets and breakdowns due to iatrogenic causes. The aim of this research was to analyse the influence of environmental effects on the corrosion and tribocorrosion properties of NiTi and stainless steel dental alloys.

Detection and characterization of stainless steel SCC by the analysis of crack related acoustic emission.

In the paper the results of the acoustic emission (AE) based detection and characterization of stress-corrosion cracking (SCC) in stainless steel are presented. As supportive methods for AE interpretation, electrochemical noise, specimen elongation measurements, and digital imaging of the specimen surface were used. Based on the defined qualitative and quantitative time and power spectra characteristics of the AE bursts, a manual and an automatic procedure for the detection of crack related AE bursts were introduced.