Atmospheric plasma spraying was employed to deposit Zirconia/Alumina (ZrO2/Al2O3) and Zirconia/Alumina-Titania (ZrO2/Al2O3-TiO2) multilayer coatings with bonding material (Ni-Cr-Al) on the EN31 Mild Steel substrate. The investigation was carried out on multilayer ceramic coated specimen by thermal torch and shock test methods. The coated specimens were prepared as per ASTM standards. Micro structural analysis was carried out using scanning electron microscope to investigate the thermal resistance of the two different multilayer ceramic coatings. The results show that the multi-layered ZrO2/Al2O3 coating possesses improved thermal properties when compared to ZrO2/Al2O3-TiO2 multilayer coating.

Atmospheric plasma spraying (APS) was employed to deposit Al2O3, ZrO2, Al2O3/ZrO2and ZrO2/Al2O3 coatings on the stainless steel substrate. Microstructural analysis of the as-sprayed coatings was carried out using scanning electron microscope (SEM). Elemental analysis of the coatings was performed using Energy-dispersive X-ray Spectroscopy (EDS) attached with SEM. The corrosion behaviors of the coatings were performed using both the potentiostat and salt spray test in 5 wt% NaCl solution. The results show that the bilayered ZrO2/Al2O3 coating possesses improved corrosion resistance when compared to the other three coatings.

The cutting forces, form of chips and the morphology of the chip influences the productivity of any machining process. In this research work, the form of chips produced and its morphology in machining Ti-6Al-4V alloy is studied under dry, wet, and cryogenic machining conditions. The cutting force, feed force and thrust force which greatly influences the efficiency of the cutting tool is also studied. Efficiency of the cryogenic cutting coolants (Carbon dioxide and liquid nitrogen) in terms of chip morphology and cutting forces are analyzed in comparison with dry and wet machining conditions. The use of cryogenic coolants yielded chips with uniform serrated teeth with low average peak value and smaller pitch values. Cryogenic CO2 coolant in particular reduced the cutting force in the range of 21 – 41%, feed force in the range of 11 – 39% and thrust force in the range of 14 – 43% when compared to wet machining.

Machining of titanium alloy Ti–6Al–4V is a challenging task because of the greatly increased cutting temperature that results in short tool life. Numerous attempts have been made in the past by employing various cutting fluids for machining purpose, including liquid nitrogen (LN2) as the cryogenic coolant. This study deals with the influence of cryogenic coolants, especially LN2 and carbon dioxide (CO2), in machining of Ti–6Al–4V and its effects on cutting temperature, cutting forces, surface roughness, chip morphology, and tool wear. The results obtained in cryogenic machining are compared with that of dry and wet machining. Cutting temperature was reduced to an extent of 36% and 47% in cryogenic CO2 machining and cryogenic LN2 machining in comparison with wet machining. The application of CO2 produced reduced cutting forces up to 24% and improved surface finish up to 48% compared to cryogenic LN2 machining. It also produced better chip control and minimized tool wear than dry, wet, and LN2 machining.

This work investigates the effect of carbon dioxide (CO2) as the cutting fluid in turning AISI 316 stainless steel work material on cutting temperature, cutting force, tool wear, surface roughness, and chip morphology when compared to dry and wet machining. Compared to wet machining, in CO2 machining the cutting temperature was reduced up to 35%, and the surface finish of the machined workpiece increased by 4–52% along with the reduced tool wear.

This experimental work is carried out to investigate the performance and influence of cryogenic coolants such as CO2 (carbon dioxide) and LN2 (liquid nitrogen) on cutting temperature, cutting force, tool wear, surface finish and chip morphology in machining of AISI 1045 steel compared to wet machining. The results proved that the application of cryogenic coolants reduced the cutting temperature drastically which resulted in appreciable improvement in surface finish of the product and reduced tool wear. The use of cryogenic LN2 reduced the cutting temperature about 3–17% when compared to CO2 coolant. Application of CO2 reduced the cutting forces and improved the surface finish of the machined part to an extent about 2–12% and 2–14% respectively when compared to the use of cryogenic LN2 coolant. Tool wear was found to be less on the application of CO2 compared to the wet and LN2 machining conditions.

The intensive temperatures in high speed machining not only limit the tool life but also impair the machined surface by inducing tensile residual stresses, microcracks and thermal damage. This problem can be handled largely by reducing the cutting temperature. When the conventional coolant is applied to the cutting zone, it fails to remove the extent of the heat effectively. Hence, a cryogenic coolant is highly recommended for this purpose. In this paper, an attempt has been made to use cryogenic carbon dioxide (CO2) as the cutting fluid. Experimental investigations are carried out by turning AISI 1045 steel in which the efficiency of cryogenic CO2 is compared to that of dry and wet machining with respect to cutting temperature, cutting forces, chip disposal and surface roughness. The experimental results show that the application of cryogenic CO2 as the cutting fluid is an efficient coolant for the turning operation as it reduced the cutting temperature by 5%–22% when compared with conventional machining. It is also observed that the surface finish is improved to an appreciable amount in the finished work piece on the application of cryogenic CO2. The surface finish is improved by 5%–25% in the cryogenic condition compared with wet machining.