The development of composite/nanocomposite coatings on various surfaces based on electroless process has much interest among researchers due to their enhanced mechanical, electrical, magnetic, and optical properties compared with their metallic or alloy counterparts. These coatings have shown many applications in automotive, aerospace and industrial fields with unique characteristics obtained by the incorporation of secondary particles as reinforcement at micro or nanoscale in the matrix. However, properties of the product depend upon not only the nature of secondary particle used but also the specific characteristics of the metal matrix. This paper critically reviews the recent developments in micro and nanostructured metallic composite coatings formed by electroless coating techniques and retrospect into the various mechanisms of the electroless coating process, its preparation with different metallic systems, properties, and applications in detail.

Electroless nickel coating is one of the versatile methods to improve the physical properties of aluminium alloys. The increasing demand for high corrosion resistant surface with improved performance leads to the development of poly-alloy and composite coatings with the aid of ultrasonication. In the present study Ni-B alloy and Ni-B-CeO2 composite coatings were made on 356 aluminium alloy surfaces. The variation in structural and mechanical properties of coatings formed under both ultrasonication and magnetic stirring were investigated. Surface analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) has shown the formation of more uniform coating under ultrasonication. The electrochemical polarization tests show enhanced corrosion resistance in ultrasonic assisted coatings.

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Shear wall has been considered as a major lateral load-resisting element in multistoried building located in wind-or earthquake-prone zone. The behavior of shear wall under various loading conditions has been the subject of intense research for the last few decades. The behavior of shear walls without openings is completely well understood and well documented in literature. The use of squat shear wall has been found in many low-rise buildings. On the other hand, squat shear walls may also be provided with openings due to the functional requirement such as placement of doors/windows in the building. The size and location of the opening play a significant role in the response of the shear wall. Even though it is intuitively known that the size of opening has significant effects on the behavior of a shear wall, it is desirable to know the limiting size of opening in the shear wall, beyond which the shear walls may fail or become unserviceable, especially when subjected to severe earthquake ground motions. In this study, the materially nonlinear dynamic response of the shear wall, with and without openings for different damping ratios, subjected to EL Centro earthquake has been captured. For dynamic analysis, constant acceleration Newmark β method of direct time integration has been used. From the study, it was observed that the presence of opening results in severe displacements and stresses on the shear wall and also results in stress concentration near the opening tip. Hence, the presence of damping has been considered to be vital for large opening under severe dynamic loading conditions.

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