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The purpose of this paper is to evaluate the corrosion of silver due to hydrogen sulphide pollutant in indoor conditions at a microelectronics plant located in Mexicali, Baja California, a semi‐arid zone in the northwest of Mexico.

Silver coupons and silver plated on to copper‐lead frames are exposed in the assembly process building of a microelectronics company during a period of 60 days and also in a sheltered test chamber that simulates indoor conditions with ambient concentrations of atmospheric pollutants, temperature and relative humidity (rH). Other exposures are made in the test chamber to study the corrosion behaviour of silver coupons over a duration of 24 months. The corrosion products were analysed using the Scanning Electron Microscope (SEM) and Energy Dispersive X‐ray Spectroscopy (EDS). Corrosion rates were measured by Quartz Crystal Microbalance (QCM) under laboratory‐controlled conditions.

The presence of silver sulphide corrosion products, dendrites and whiskers is observed on the exposed samples using SEM and EDS analysis.

The paper is designed to establish whether the company, where the exposure is taking place, constituted an indoor environment with outdoor hydrogen sulphide pollutant in sufficient concentration to induce silver corrosion.

The methodology used in this work can be applied to study the indoor corrosion behaviour of other metals, which will be of interest to the microelectronics industry.

Colonies of Actynomyces israelii bacteria have been found in removed copper intra‐uterine devices (IUD) used as a long‐term contraceptive method. The purpose of this paper is to characterize the biofilm developed under anaerobic conditions by Actynomyces israelii on IUD surface, and its influence in the copper corrosion processes.

The dissolution of copper on the intra‐uterine cavity prevents conception because of the toxic effect of the ions released. Nevertheless, microbiological growths have been detected on the IUD devices retired after long periods of insertion. In order to know about the influence of the biofilm on the corrosion of copper, electrochemical, spectroscopic and surface analysis techniques were applied to study the phenomenon.

A porous Actynomyces israelii biofilm was formed on the copper IUD surface. The bacteria colony had developed in an exopolimeric substrate, which protects it from the toxic effect of copper ions. The corrosion process was not inhibited by the biofilm, due to the pores present which permit the transport of species through them.

The results of this study show that there is no decay in the contraceptive function of the IUDs due to the presence of a bacterial biofilm on its surface.

The relationship between microbial colonization and the corrosion process of copper IUD under anaerobic conditions was characterized. These results will complement previous investigations performed on the study of corrosion of copper IUDs under different conditions.

Aggressive environments that enhance indoor corrosion in industrial plants decrease the yielding of electronic equipment, causing electrical failures. The purpose of the present paper is to evaluate corrosion rates in metals used in electronic devices as a function of temperature, humidity and the concentrations of some air pollutants in order to predict the optimal conditions preventing or minimizing corrosion.

Atmospheric pollutants mainly sulphur oxides, penetrating through small crevices and holes into electronic plants in combination with climatic factors such as humidity and heat, promote corrosion. The corrosion rate of the five most used metals in the electronics industry: carbon steel, copper, nickel, silver, and tin, were studied gravimetrically as a function of variations in humidity, temperature and air pollutant concentrations from 2003 to 2005. The samples were exposed in an instrumented boot to indoor conditions and gravimetric measurements were performed together with measurements of the above‐mentioned parameters. Mathematical simulation applying Math Lab software was carried out as well. The ternary diagrams for pollutants, temperature and relative humidity were applied as a useful tool to correlate these parameters in indoor conditions with the corrosion rate of metals applied in the electronics industry.

The obtained results have shown that the presence of even small concentrations of air pollutants promoted corrosion processes when time of wetness conditions were reached.

The study was carried out in order to minimize the corrosion losses of the electronic plants situated especially in Mexicali City located on a semi‐desert zone in the Northwest of Mexico.

This paper establishes the relationship of variations of pollutants concentration, temperature and the relative humidity with the corrosion rate of metals in indoor conditions in the electronics industry located in the semi‐arid zone of Mexicali. Design was characterized and simulated using the MathLab software.

The purpose of this paper is to investigate the corrosion of the heat‐affected zone (HAZ) and weld zone of austenitic stainless steels that have been welded using two different processes. The corrosion behavior is evaluated in synthetic seawater using the electrochemical polarization technique.

Welded and unwelded UNS S30403 specimens were welded by flux core arc, and gas tungsten arc welding (GTAW) techniques. The test equipment consisted of an electrochemical three‐electrode cell using synthetic seawater as the corrosive medium. The scan rate was 10 mV/s and the potential range was −500‐500 mV vs saturated calomel electrode. The pH for the synthetic seawater was around seven. The electrochemical tests were performed after 1, 2, 3, and, 11 weeks. The metal surface was characterized by examination using an inverted microscope and scanning electron microscopy.

The polarization measurements of the flux core arc welding‐HAZ showed a high corrosion susceptibility, while GTAW‐HAZ presented good corrosion performance.

With the application and correct interpretation of this electrochemical technique, designers, welding engineers, and manufactures can access important information and take correct decisions regarding welding processes to meet corrosion resistance requirements.

The methodology and approach of interpreting the polarization plots used in this research can be applied to study other welding techniques and different welded metals in specific corrosive media, which will be of value to the welding industry.

To develop and test a rapid method for evaluation of the corrosion protection (CP) of carbon steel (CS) by vapour corrosion inhibitors (VCI) films.

The determination of the CP by VCI on CSs is commonly carried out in a chamber applying neutral salt spray (NSS) and usually it takes many days. The common disadvantage of the various rapid methods created until now is the need of special laboratory equipment making their application complicated and inconvenient for field tests. The method for CP measurement of VCI films on CS described in this study is based on measurement of the height of the anodic peak under galvanostatic condition applied earlier on other types of films and coatings. By means of a calibration plot: peak height (V) vs NSS protection time (s), CP of VCI films on CS specimens expressed in hours NSS is determined in a few seconds without using an NSS chamber. Measurements of CP by VCI films under field conditions are performed applying a hand held tester.

Two groups of CS UNS G10180 steel specimens with increasing thickness of VCI films were studied – one in an NSS chamber and the second by the application of a corrosion tester. The correlation between the results obtained for the two groups of specimens was found and a calibration plot was made.

Based on this method, a special corrosion tester was developed, able to measure under field conditions as well.

The method subject of the paper is a further development of a galvanostatic method developed by the authors for CP evaluation of chromate films of Zn and Cd coatings. The method was modified according to the properties of VCI films

To investigate the protective properties of tantalum nitride (TaN) thin films deposited on to various steels immersed in a 3 per cent NaCl solution.

TaN thin films with a thickness of 250 nm were deposited on UNS G10180, UNS S30400 and UNS T11302 steels by means of magnetron sputtering technique. The electrochemical behaviour has been studied in 3 per cent NaCl solution using electrochemical impedance spectroscopy and potentiodynamic polarization. The crystalline structure of the films was investigated by X‐ray diffraction. Surface analysis of the corroded samples was performed using scanning electron microscopy and light optical microscopy. The electrochemical impedance spectra were analysed in the context of equivalent circuit models (ECs).

The ECs incorporate a charge transfer process representing the TaN film on UNS G10180 steel, two time constants for that deposited on UNS T11302 and diffusion behaviour for the TaN film on UNS S30400 steel. TaN films demonstrate their protection properties, which were evidenced by increase of the electrochemical properties compared with the substrate. The major corrosion damage of coatings is caused by defects, pores, droplets and pinholes that allow the electrolyte penetration through the films.

Corrosion protections of steels by TaN thin films.

The information related to corrosion behaviour of TaN films in a chloride solution is poor. This paper presents not only a completely electrochemical characterization, but also the surface analysis of the corroded samples.

The purpose of this investigation was to develop a digital instrument for the quantitative evaluation of pitting corrosion in metals.

This investigation comprised two central parts: research, testing and monitoring of the formation of pitting by conventional methods and applying American Society for Testing and Materials (ASTM) Standards, and the development of a virtual instrument based on the LabVIEW 2010 platform.

The methodology used was suitable for the analysis of pitting on carbon steel and aluminum alloy UNS A96061, used in the aerospace industry.

This technique allows pits to be to localized, measured and quantified on metallic surfaces, for corrosion evaluation in atmospheric and industrial environments.

This combination of conventional and digital methods can assist in corrosion control of pitting in industrial equipment.

The purpose of this paper is to study the indoor corrosion of metals used in the electronics industry, as influenced by climate factors.

Corrosivity levels inside industrial plants were evaluated to evaluate the deterioration of metals.

Relative humidity, temperature, and time of wetness are recorded and related to the corrosion process.

Control of climate factors indoors in industrial plants to reduce and control the corrosion process of metals used in the electronics industry.

The electronics industry has grown over the past 50 years, mostly in developed countries, contributing to their economic progress. Particularly in the Baja California State located in the northwest of Mexico, these companies have prospered in the industrial parks of Mexicali considered as an arid zone and Ensenada, a port and city on the Pacific Ocean considered as a marine region. In both environments, during winter and summer, the climate impacts on indoor conditions, affecting humidity and temperature, and generating corrosion which decreases the yields of the electronic devices and industrial machines. The purpose of this paper is to investigate the effects of corrosion on electronic devices in these arid and marine environments.

The paper determines the corrosivity levels inside industrial plants of desertic and coast regions in Mexico, to evaluate the deterioration of electronic metals.

Relative humidity, temperature, time of wetness, are recorded and related to the corrosion process in arid and marine environments.

Some missing information about air pollution in Ensenada from some Environmental Monitoring Stations was a limitation, and the need to use complex atmospheric techniques.

The paper shows that it is very important to control metallic corrosion generated by climate factors and air pollution in indoor industrial plants: the corrosion of electronic devices and equipments depletes their yield and can lead to loss‐making failures.

Sound microstructure components are necessary for reliability and safety; hence, these components are used in aircraft, satellite, automobiles and ships, where many commercial alloys are not suitable. The paper aims to discuss this issue.

AA6082/Si₃N₄ and AA6082/SiC composites were fabricated using the stir-casting process considering 5, 10 and 15 vol.% of reinforcement particles. Density and porosity of AA6082/Si₃N₄ and AA6082/SiC composites were calculated. Characterization was done using an X-ray (EDX) detector, attached to SEM. The effect of addition of Si₃N₄ and SiC particulates in the AA6082 was investigated.

Results showed that Si₃N₄ and SiC particulates had good wettability with AA6082 and were uniformly distributed in AA6082 matrix. No adverse effects of reactions were noticed in the microstructure of AA6082/Si₃N₄ and AA6082/SiC composites.

AA6082 with more than 15 vol.% of Si₃N₄ and AA6082/SiC reinforcement particles do not find industrial application where high hardness and tensile strength are required.

Components made from AA6082/Si₃N₄ and AA6082/SiC composites find their application where high hardness with better tensile strength is required.

Naturally and locally available materials are utilized for fabrication.

Little work is available in the literature on fabrication and characterization of AA6082/Si₃N₄ and AA6082/SiC composites. The authors have identified the process parameters at which proper fabrication is done and sound microstructure is obtained.