K P Sreekumar

Erosion Wear Analysis of Plasma Sprayed Ceramic Coating Using the Taguchi Technique

Erosion wear behavior of fly ash–illmenite coating was studied using dry silica sand as an erodent. A plan of experiments based on the Taguchi technique was used to acquire the data in a controlled way. An orthogonal array and signal-to-noise ratio was employed to investigate the influence of the impact angle, the velocity, the size of the erodent, and the standoff distance (SOD) on erosion wear. The objective was to investigate which design parameter significantly affects the erosion wear. It was found that the impact angle is the most powerful factor influencing the erosion wear rate of the coating. Further, when erosive wear behavior of fly ash–illmenite coating was investigated at three impact angles (i.e., at 30°, 60°, 90°), it was revealed that the impact angle is the prime factor and maximum erosion takes place at α= 90°.

Tribo-Performance Analysis of Fly Ash–Aluminum Coatings Using Experimental Design and ANN

This article proposes the application of an artificial neural network (ANN) to a Taguchi orthogonal experiment to develop a robust and efficient method of analyzing and predicting the solid particle erosion wear response of a new class of metal–ceramic coatings. An ANN model based on data obtained from experiments performs self-learning by updating weightings and repeated learning epochs. In this work, plasma-sprayed coatings of fly ash premixed with aluminum powder in different weight proportions are deposited on aluminum substrates at various input power levels of the plasma torch. Erosion wear characteristics of these coatings are investigated following a plan of experiments based on the Taguchi technique, which is used to acquire the erosion test data in a controlled way. The study reveals that the impact velocity is the most significant among various factors influencing the wear rate of these coatings. An ANN approach is then implemented taking into account training and test procedure to predict the tribo-performance under different erosive wear conditions. This technique helps in saving time and resources for a large number of experimental trials and successfully predicts the wear rate of the coatings both within and beyond the experimental domain.

Investigation on Composite Coating of Low Grade Minerals

In this investigation, coatings of fly ash (an industrial waste) mixed with illmenite (a low grade ore mineral) have been deposited on mild steel and copper substrates using conventional atmospheric plasma spray technique. Micro-hardness measurement, phase composition analysis, coating porosity measurement, and surface and interface morphology are studied to characterize the coatings.

Wear Characteristics of Plasma Sprayed Nickel-Aluminum Composite Coatings

In the present investigation plasma spray intermetallic coating of nickel—aluminide was deposited on mild steel substrates. The response of plasma sprayed nickel—aluminide coatings to the impingement of solid particles has been presented in this study. Nickel pre-mixed with alumina powder is deposited on mild steel substances by atmospheric plasma spraying at various operating power level. The coatings are subjected to erosion wear test. Dry silica sand of average particle size 400 μm is used as the erodent. The erosion rate is calculated on the basis of coating mass loss. The erosion studies are made at different velocities and impingement angles. It is observed that, the erosion wear is strongly influenced by the angle of impact. The test is conducted at room temperature, i.e., at 27°C and 60% RH. Coatings deposited at different power levels are found to exhibit different wear rates under similar test conditions. Microstructure of the coating is analyzed with SEM.