Working with nanomaterials requires descending to the atomic level of materials. Hence, the development of SEM and TEM played a large part in the rise of the science and technology of nanomaterials. A lot of research has focused on nanoscience and nanotechnology in the last two decades. There is ongoing development of nanomaterials with unique advantageous properties. This research looked at the problems associated with the production and preparation of nanomaterials and the improvement in the mechanical, physical, thermal, electrical, and chemical properties of the classical materials (metals, polymers, composites, etc.) that may be made into nanomaterials. This paper explains some of the basics of nanomaterials and reviews the behavior of the traditional mechanical properties in nanocomposites with different reinforcements and matrices.

Welding is widely used in the construction of metallic structures. In service, these structures are prone to failure under different types of loadings: static and dynamic. A welding joint should have adequate strength to withstand these type of loadings under the service conditions which is designed to serve within them. This work tries to hold a comparison between two common welding techniques in the local workshops from the point view of strength. The research program included: tensile strength, impact strength, and micro hardness. As received structural bars of mild steel were cut and square butt welded. Two fusion welding techniques was selected: arc welding and oxy-acetylenewelding for the availability of their equipment and possibility of using them outdoor. The results obtained during this humble work suggest that from the perspective of tensile strength, oxy-acetylene welding is better than shielded metal arc welding, while the latter is characterized by higher micro hardness and impact strength.

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Abrasive wear is an engineering problem that occurs in the impeller of centrifugal water pumps. The weight loss in the impeller due to abrasive wear leads to a reduction in the efficiency of pumps. If the wear rate can be estimated, the pump impeller can be replaced at the perfect time. The aim of the present experimental study is to investigate the abrasive wear of brass alloy in sand-water mixture. In this study, a mixture of sand-tap water was used with three mixing ratios (1:40, 1:80 and 1:120) and four different sand particles sizes (0.15 mm, 0.297 mm, 0.6 mm and 1.19 mm). A set of brass alloy impellers was used to estimate the abrasive wear rate when tested at five periods. From the results of this study, it can be concluded that the sand particles size and sand-tap water mixture ratios have a direct effect on the wear rate of the impeller and water pump head.