Sol-gel process is categorized as a well-known and reliable coating process. The useful characteristics of this method are composition selection, easy to coat complex mechanical parts, geometries, homogeneity of the coating layer and easiness of the process. To this end, the process has been implemented in many applications from powder industry to electronics. However, compared with coating techniques, this method suffers from slow process speed and inherent cracks in the body of solidified gel. This process is meant to provide a coating layer that acts as a protective barrier on the surface of the materials such as optic applications. However, there are many other uses such as sensing applications and powder making that might be unknown or not studied thoroughly. In this study, after a brief explanation of the process, some of the most important applications are reviewed.

No abstract

In recent years, a new generation of composite materials has been introduced as metal matrix composites (MMCs) in order to simultaneously provide higher strength and stiffness. Industrial interests resulted in deep investigations and researches on machinability of MMCs and especially in the field of high-speed machining. High-speed machining processes offer a higher machining efficiency and reduced cost of the process, which made them the process of interest in many manufacturing industries. However, matrix reinforcement by addition of hard particle phases to the MMCs significantly increases machining difficulty, tool wear, surface quality deterioration and overall fabrication costs. In the current research, the cutting speed, feed rate, depth of cut, presence of cryogenic coolant and their effect on the tool wear of high-speed machining of Al/SiC MMC reinforced with 15 wt% SiC particles have been investigated. The results have shown that silicon carbide particles in the aluminum matrix cause a severe tool wear. However, the severity of tool wear has decreased by applying a cryogenic cooling.