Slurry erosion is a serious menace in most of the hydro machine components all around the globe. Slurry erosion is accountable for heavy economic losses. However, some counter measures are being taken to mitigate the effect of sand particles passing through hydro-machine parts and research is also underway to improve the component surface by applying different surface coatings. Laser cladding is a surface deposition process that is used to achieve very good metallurgical bonding with minimum porosity as compared to other surface coating techniques. In this research paper, an attempt has been made to compile the literature related to laser cladding technology, its applications, process parameters, coating materials and their effectiveness to bestow solutions to various types of surface degradation with special emphasis on slurry erosion problems. This paper will serve as a reference for the researchers working in the area of slurry erosion prevention.Erosion is described as wear induced by solid particles hitting a surface, transferred via a gas flow or entertained in a fluid streaming medium [16]. The impinging angle of the particles and relative velocity determines the abrasive wear on a surface [17]. Hydro abrasive erosion depends upon several parameters such as size of sand, hardness, concentration, shape, quantity, and velocity, in most cases minimizing the impact energy of the particles by monitoring the parameters mentioned or indirectly. Despite this, enormous surface destruction to hydroelectric devices and structures occurs at any stage at a sufficiently elevated velocity, causing scratching and removal of material [18]. It has been learned that because of their excellent corrosion characteristics and acceptable resistance to strong particle erosion, in hydroelectric power plants stainless steels are widely used [16]. Bitter [19] suggested two erosion wear theories: cutting and deformation, according to him, the cutting wear is triggered by the particle velocity element parallel to the target surface, whereas the deformation wear is accountable for the normal component of the velocity. Some researchers [20-24] indicated that hardness of the target material or hardness of the impacting solid particles was dominant for wear of target surface. Wang and Yang [25] noted that a dominant function in the erosion process is the surface hardening of metals. The worn surfaces were analysed by scanning electron microscope and different wear processes such as micro-ploughing, lip formation, platelet, tiny indentation craters, and micro-cracking were described. It was reported that the depletion of materials such as metals and alloys was produced by the micro-cutting and microploughing of strong particles for ductile materials. The crack coalescence results in the removal of large-scale components for brittle materials.Material degradation by the dint of slurry erosion relies on myriad variables that can be classified into three primary groups: the first one associated with fluid flow circumstances (flow speed, partic...

This study presents the joining process of plates with thickness of 4  mm in AA2014 and AA6061 through Friction Stir Welding (FSW) process under alternative tool rotating speeds. AA2014-T6 and AA 6061-T6 alloys were friction stir welded with cylindrical eased pin tool at different revolving speeds such as 700, 900 and 1100  rpm and constant welding speed of 50  mm/min. Mechanical behavior of the FSW of an aluminum alloy exposes a key role of the microstructure. The microstructure change in the interfacial region is characterized using Optical Microscopy (OM). The average grain size was determined based on ASTM E112 – 12 standards. The mechanical properties like tensile strength, micro hardness, and flexural strength of the dissimilar aluminum alloys were evaluated. The fracture examination of the tensile samples was evaluated using Scanning Electron Microscope (SEM). Distance Amplitude Curve (DAC) shows that no recordable internal discontinuities are observed for all three weldments. Further, the study articulated that the effect of rotational speed (900  rpm) exhibits better hardness, tensile and flexural strength. In addition, there was a significant improvement in the grain structure and the average % of grain structure with an average grain size was found to be 15.6 µm and it directly influences the mechanical properties.

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