Graphene - Its role in energy storage devices

This presentation provides an overview of graphene, methods of preparation of graphene, important applications and its role in energy storage devices, namely, fuel cells, supercapacitors, lithium batteries and hydrogen storage

Magnesium: A wonder material?

This presentation is aimed to give a glimpse of the role of Mg in human life and healt

Surface pretretament by phosphate conversion coatings - A review

Phosphating is the most widely used metal pretreatment process for the surface treatment and finishing of ferrous and non-ferrous metals. Due to its economy, speed of operation and ability to afford excellent corrosion resistance, wear resistance, adhesion and lubricative properties, it plays a significant role in the automobile, process and appliance industries. Though the process was initially developed as a simple method of preventing corrosion, the changing end uses of phosphated articles have forced the modification of the existing processes and development of innovative methods to substitute the conventional ones. To keep pace with the rapid changing need of the finishing systems, numerous modifications have been put forth in their development - both in the processing sequence as well as in the phosphating formulations. This review addresses the various aspects of phosphating in detail. In spite of the numerous modifications put forth on the deposition technologies to achieve different types of coatings and desirable properties such as improved corrosion resistance, wear resistance, etc., phosphate conversion coating still plays a vital part in the automobile, process and appliance industries

The role of surfactants in phosphate conversion coatings

Surface active agents occupy a predominant role in the metal finishing industry. Being capable of reducing the surface tension and improving the wettability of the surface, the importance of such additives is very well realized and phosphating baths have been developed with surfactants as one of the additives. However, surfactant additives could influence the nucleation and growth of phosphate crystals and alter the kinetics of the phosphating process. Addition of surfactants in phosphating baths is beneficial in obtaining the desired orientation of the phosphate crystal and the crystallites of the base metal, leading to an improved adherence and excellent corrosion resistance of the resultant phosphate coating. The influence of surfactant additives on the nucleation, growth, refinement of crystals and the continuous dissolution and re-precipitation of the phosphate coating, calls for a through understanding of role of surfactant additives often incorporated in phosphating baths so that the desirable qualities can be successfully built-in in the resultant phosphate coating

Corrosion Science and Engineering

This presentation provides an overview of corrosion and corrosion prevention method

Tin plated contacts - Problems due to fretting corrosion and whisker growth

This presentation provides an overview of the most common type of failures in tin plated contacts - fretting corrosion and whisker growth. The fretting corrosion behaviour of tin plated copper contacts as a function of different conditions were addressed. The mechamism of fretting corrosion is proposed

Effect of surface nanocrystallization on the corrosion behaviour of AISI 409 stainless steel

The influence of surface mechanical attrition treatment (SMAT) on the corrosion behaviour of AISI 409 grade stainless steel in 0.6 M NaCl was studied. SMAT using 2 mm £ 316L stainless steel (SS) balls for 15, 30 and 45 min and 5 mm £ balls for 15 min offers a better corrosion protective ability. In contrast, treatment using 5 mm £ balls for 30 and 45 min and by using 8 mm £ balls for 15, 30 and 45 min,induces microstrain and defect density that results in a decrease in corrosion resistance

Thermal properties of siliconized epoxy interpenetrating coatings

This work involves the development of a novel siliconized epoxy interpenetrating coating system using epoxy resin as base, hydroxyl-terminated polydimethylsiloxane (HTPDMS) as modifier, γ-aminopropyltriethoxysilane (γ-APS) as crosslinking agent and dibutyltindilaurate (DBTDL) as catalyst. Polyamidoamine and aromatic polyamine adduct were used as curing agents for the above coating systems. The thermal behaviour, glass transition temperature (Tg) and morphological characteristics of unmodified epoxy and siliconized epoxy coating systems cured by polyamidoamine (B) and aromatic polyamine adduct (D) were studied using thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy, respectively, and the results are discussed. From the study, it is observed that the thermal stability of epoxy coating systems is enhanced when siloxane is incorporated to them. There is a slight decrease in the glass transition temperature observed for silicone-modified epoxy coatings and SEM analyses reveal that siliconized epoxy coating systems show heterogeneous morphology