Dr. Yuvaraj N

The purpose of the present investigation was to evaluate the abrasive water jet cutting performance by the application of a cryogenic liquid nitrogen jet in the cutting process. This technique was developed for improving the process capability of conventional abrasive water jet machining and enable a higher depth of cut and material removal rate, and better kerf profile and surface integrity. The experiments were conducted on AA5083-H32 aluminium alloy, using two different cutting methods, namely, abrasive water jet cutting and cryogenic assisted abrasive water jet cutting. Both cutting conditions were investigated by varying the water jet pressure, the abrasive mesh size and the abrasive water jet impact angle. Optical microscopy and Scanning Electron Microscope with Energy Dispersive X-ray Spectroscopy was used for studying the micro structure and morphology of the cut surfaces under both cutting conditions. There was an improvement in cutting performance features such as depth of penetration, material removal rate and kerf profile with the use of cryogenic assistance cutting approach. These results were produced due to the beneficial modification of erosion mechanism in the cutting zone as well as a reduction in particle embedment with the cut surface by about 56%.

Nowadays, advanced machining techniques are widely used for solving various issues in manufacturing operations that include machining high strength materials, production of complex shaped profiles, better surface features, capable of high levels of precision, miniaturization, reduction of waste and secondary operations and lower production time. Among the various advanced machining techniques, abrasive water jet (AWJ) machining has received more attention from researchers and practicing engineers in manufacturing industries due to its capability of extensive operations and excellent quality of the cutting edge obtained during this process much superior to others, is reported by previous researchers. AWJ process is classified into abrasive water injection jet and abrasive slurry jet on the basis of the different ways of mixing between abrasive and water. This study explores the researches made on Injection type AWJ machining process as it is widely accepted by researchers and Industries for solving various issues. Review articles on AWJ have been collected from the year of 1960–2019. Hence, this study provides a detailed report on AWJ machining process (majority of discussion on metals and their compounds) through demonstration of various studies on subjects that include performance and surface characteristics, hybrid processes, versatile operations, micro machining and medical applications. A literature survey of recent trends and their applications of AWJ process has also been documented. Optimization studies have been discussed with various techniques used in the AWJ machining process. This has been referred to in this paper. In addition, future opportunties in AWJ have been discussed including a demand for requirements in various fields. The entire collection of results are of help in finding the niche applications for manufacturing operations in future. The outcome of this paper would also support present and future researchers in the identification of the significant process parameters, work materials and advanced techniques for getting better results in AWJ machining process.

This paper reports the identification of abrasive water jet process parameters for the cutting of AA5083-H32 aluminium alloy using the fuzzy TOPSIS method. Such identification requires a precise work in abrasive water jet (AWJ) cutting, considering that it determines the quality and performance of the process. In the present work, optimisation studies were carried out through using the fuzzy TOPSIS method for the determination of better optimal process parameters. The Taguchi full factorial method was used for the experimental design and the weighting of each output response was determined by a triangular fuzzy number method. The selection of optimal input parameters such as water jet pressure of 150 MPa, abrasive mesh size of #80 and jet impingement angle of 80º have been suggested for the precise work conducted in AWJ. A scanning electron microscope (SEM) was used for examining the AWJ cut surfaces at the optimal level of process parameter settings. An energy dispersive X-ray spectroscopy was employed to confirm the number of silicon particles embedded in the cut surfaces. The experimental result indicates the improvement in the quality of AWJ cutting by the fuzzy TOPSIS method through the identification of better optimal input process parameters.

This paper investigates the 3D surface topography, 2D roughness profiles and micrographs were analyzed in the abrasive water jet (AWJ) cutting of AISI D2 steel kerf wall cut surfaces by varying water jet pressures and jet impact angles. In 3D surface topography, roughness parameters such as Sq, Ssk, Sp, Sv, Sku, Sz and Sa were improved
by various jet impact angles with different water jet pressures. However, the roughness parameters Ssk and Sku strongly depend on the water jet pressure and jet impact angle.This is confirmed by kerf wall cut profile structures. Fine irregularities of peaks and valleys are found on the AWJ cut surfaces, as evident from 2D roughness profiles. The SEM micrographs confirm production of an upper zone not very much damaged and a lower striation free bottom zone, by using the jet impact angle of 70o with a water jet pressure of 200 MPa. Finally, the results indicate a jet impact angle of 70o maintaining the surface integrity of D2 steel better than normal jet impact angle of 90o. The results are
useful in mating applications subjected to wear and friction. This has resulted in enhancement of the functionality of the AWJ machined D2 steel components.

In the present experimental study, abrasive water jet (AWJ) cutting tests were conducted on D2 steel by different jet impingement angles and abrasive mesh sizes. The experimental data was statistically analyzed using the simos-grey relational method and ANOVA test. In addition, the outcome of influencing cutting parameters, namely jet pressure, jet impingement angle and abrasive mesh size on the different response parameters, namely, the jet penetration, material removal rate, taper ratio, roughness and topography, were studied. Micro hardness test and surface morphology analyis were employed to examine the D2 cut surfaces at different AWJ cutting conditions. The chemical element study was performed to determine the abrasive particle contamination in the AWJ kerf wall cut surfaces. The ANOVA test result indicated the jet pressure and jet impingement angle as the influencing process parameters affecting the various performance characteristics of AWJ cutting. The overall AWJ cutting performance of the D2 steel has been improved through proper identification of the optimal process parameter settings, namely jet pressure 225 MPa, abrasive mesh size #100 and jet impingement angle 70° by the simos-grey relational analysis.

Cryogenic assisted machining is a recent machining technique, which is used for producing definite components with a satisfactory surface condition. In the present work, surface integrity studies have been carried out on the abrasive water jet (AWJ), and cryogenic assisted abrasive water jet (CAAWJ) cutting of AA5083-H32 aluminium alloy by varying the jet impingement angles and abrasive mesh sizes. Micrographs, surface morphology, 3D surface topography, 2D roughness profile, XRD peak analysis, surface residual stress and micro-hardness have been characterized in the AWJ, and CAAWJ cut surfaces. Of the two cutting conditions, the CAAWJ cutting process enhances the functional performance of the cut surfaces, leaving no traces of severe wear tracks, while obtaining a uniform roughness profile pattern, higher surface compressive residual stress and hardening. The results indicate the effect of variations in the jet impingement angles, and the abrasive mesh sizes contributing a satisfactory surface condition, existing in CAAWJ by the Liquid Nitrogen jet.

The chapter reports on the investigation of cryogenic-assisted abrasive water jet (CAAWJ) machining of AISI D2 steel with varying the jet impact angles and abrasive mesh sizes. The performance measurement is considered in this study such as depth of penetration and taper ratio. Also, the surface integrity characteristics are considered in the present study such as abrasive contamination, surface topography, XRD peaks, residual stress, and micro hardness. The CAAWJ machining process improves the performance measurement such as higher depth of penetration and lower taper ratio for the machining of D2 steel. Also, the CAAWJ cut surface consists of better surface integrity features over the AWJ cut surface. The phase transformation effect of target material under cryogenic cooling helps to turn the mode of the material removal mechanism from ductile to brittle erosion process and yield a better performance. The results also indicate that the oblique jet impact angles have been produced better performance characteristics than the jet impact angle of 90 o at room temperature.