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Tungsten carbide tool places in are coated by customized composition of Ti/TiCN/TiN/TiCN/TiN for multilayer and monolayer TiC-C using PVD assisted CAE technique. Quality physiognomies of coatings are evaluated using VDI3198 and Calo tests. Thickness of the coatings for Ti-multilayer and monolayer are found to be 1.837 and 1.198 µm respectively and adhesion quality of HF1 attained. Highly alloyed steel MDN431 is used as machining material to evaluate the performance of coatings. The coated tool insert performance has been evaluated at the machining parameters cutting speed in the range of 59-118 m/min, feed rate is 0.062-0.125 mm/rev and depth of cut is ap 0.2-0.4 mm during machining of MDN431 steel. Experiments are conducted based on L27 full factorial design. Cutting forces and surface roughness are analysed using regression analysis. Desirability approach as well as PSO technique is used to optimize the process parameters. Least cutting force and surface roughness are obtained at the condition of Vc-118 m/min, f-0.063 mm/rev, ap-0.2 mm and Vc-59 m/min, f0.063 mm/rev, ap-0.2 mm for Ti-multilayer and TiC-C coatings respectively. To augment the capability of predictive regression models and coefficients of determination (COD), ANN modelling has been adopted. Cutting forces and surface roughness are predicted using ANN and mathematical regression models, predicted data follows the experimental data with minimum absolute error. Tool wear was reduced by 65.7% in Ti-multilayer and TiC-C coated tools compared to uncoated tool. [ABSTRACT FROM AUTHOR]

Turbine forgings and other components are required to be high resistance to corrosion and oxidation because which they are highly alloyed with Ni and Cr. Midhani manufactures one of such material MDN431. It’s a hard-to-machine steel with high hardness and strength. PVD coated insert provide an answer to problem with its state of art technique on the WC tool. Machinability studies is carried out on MDN431 steel using uncoated and Ti-multilayer coated WC tool insert using Taguchi optimisation technique. During the present investigation, speed (398-625rpm), feed (0.093-0.175mm/rev), and depth of cut (0.2-0.4mm) varied according to Taguchi L9 orthogonal array, subsequently cutting forces and surface roughness (Ra) were measured. Optimizations of the obtained results are done using Taguchi technique for cutting forces and surface roughness. Using Taguchi technique linear fit model regression analysis carried out for the combination of each input variable. Experimented results are compared and found the developed model is adequate which supported by proof trials. Speed, feed and depth of cut are linearly dependent on the cutting force and surface roughness for uncoated insert whereas Speed and depth of cut feed is inversely dependent in coated insert for both cutting force and surface roughness. Machined surface for coated and uncoated inserts during machining of MDN431 is studied using optical profilometer. [ABSTRACT FROM AUTHOR]

Present studies deals with comparison of high velocity oxy fuel and flame spray coating process by developing CoMoCrSi (Tribaloy T400) coating on a titanium grade-15 substrate. Prior to coating, feedstock is processed to obtain higher fraction intermetallics through high energy ball milling technique under controlled atmosphere. Processed feedstock material is sprayed on a Ti-15 substrate through HVOF and Flame spray process. The coated specimens are subjected to metallurgical and mechanical characterization using optical microscope, scanning electron microscope, energy dispersive spectroscopy, x-ray diffraction, Vickers mico hardness tester and bond strength using pull off test method. HVOF sprayed coating exhibits superior properties compared to Flame sprayed coating in terms of surface roughness, porosity, micro hardness and adhesion strength. The detailed studies of two coating systems is discussed. [ABSTRACT FROM AUTHOR]