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Assessment of machinability of inconel 718: A comparative study of CVD & PVD coated tools

Tue, 01 Oct 2019 00:00:00 GMT

Title: Assessment of machinability of inconel 718: A comparative study of CVD & PVD coated tools Authors: Yadav, Rajiv Kumar; Chatterjee, Suman; Abhishek, Kumar; Mahapatra, Siba Sankar Abstract: This paper highlights the parametric appraisal in turning of inconel 718 using fuzzy inference system coupled with imperialistic competitive algorithm (ICA) approach. The machining variables such as spindle speed, feed rate and depth of cut have been taken into consideration to analyse their effect on evaluation characteristics viz. material removal rate (MRR), flank wear and surface roughness. Fuzzy inference system (FIS) has been used to integrate aforementioned evaluation characteristics into a single response known as multi performance characteristic index (MPCI) to address the issue of impreciseness and uncertainties involved in decision making. Mathematical models have also been proposed for MPCI using non-linear regression analysis which acts as an objective function in ICA. ICA is new meta-heuristic based on social political theory which is used to obtain global optimal parametric combination in machining of Inconel 718. The results indicate that single layer (single coating: AlTiN) physical vapour deposition (PVD) coated tool is more efficient as compared to multi-layered (four coatings: TiN, TiCN, Al₂O₃ and TiN) chemical vapour deposition (CVD) coated tool. Page(s): 281-297

Analysis and characterization of weld quality during butt welding through friction stir welding

Tue, 01 Oct 2019 00:00:00 GMT

Title: Analysis and characterization of weld quality during butt welding through friction stir welding Authors: Pandey, Ankit Kumar; Chatterjee, Suman; Mahapatra, Siba Sankar Abstract: In the present study, butt weld produced by friction stir welding of aluminium 1060 alloy has been analyzed. Destructive test, non-destructive test, and SEM image analysis methods have been implemented to investigate the microstructural evolution and mechanical properties of welded joints. The effects of tool rotation speed, welding speed, tool pin profile and tool offset have been investigated to optimize welding conditions for required weld properties. Face-centered central composite design of response surface methodology has been adapted to analyze the effect of parameters with an optimal number of experiments. It has been observed that weld produced with threaded pin tool has higher ultimate tensile stress and ultimate flexural stress. Radiography test has shown that cracks are not present in the produced weldment. From the study of the fracture surface of the tensile test specimen, it has been found that ductility of weld is highest at the top area and decreases towards the bottom area of weld. Dimple formation has been found at the top area of the fracture surface but has been absent in the bottom area of weld. Vickers hardness of weld zone and the heat affected zone has found to be less than the base material. Page(s): 298-310

MQL assisted cleaner machining using PVD TiAlN coated carbide insert: Comparative assessment

Tue, 01 Oct 2019 00:00:00 GMT

Title: MQL assisted cleaner machining using PVD TiAlN coated carbide insert: Comparative assessment Authors: Das, Rabin Kumar; Sahoo, Ashok Kumar; Kumar, Ramanuj; Roy, Sudesna; Mishra, Purna Chandra; Mohanty, Tanmaya Abstract: Minimum quantity lubrication (MQL) is an alternative over dry machining due to economic and ecological sustainability. In the current research, a comparative investigation has been carried out on machinability and surface integrity aspects of hardened AISI 4340 steel using PVD TiAlN coated carbide inserts during dry and MQL assisted hard turning. Under the dry condition, turned surface has been encountered tensile residual stress whereas compressive residual stress has been generated under MQL condition. Formation of a white layer on the chip has not been experienced under both conditions. Cutting speed predominantly influences tool wear and feed influences more on surface roughness. Dimensional deviation and auxiliary flank wear have been significantly reduced under MQL condition with 16.21% cost savings. An improvement in machinability characteristics and surface integrity under MQL cutting has been noticed compared to dry with favorable interaction and contribute towards cleaner machining process. This may be adopted in machining shop floor as a good replacement over dry machining. Page(s): 311-325

Optimization of multipoint incremental sheet metal forming of SS430 sheets using GRA

Tue, 01 Oct 2019 00:00:00 GMT

Title: Optimization of multipoint incremental sheet metal forming of SS430 sheets using GRA Authors: Ramkumar, Kathalingam; Baskar, Neelagandan; Paulraj, Gopalan; Elangovan, Krishnan; Narayanan, Chinnaiyan Sathiya Abstract: Incremental sheet metal forming (ISF) is one of the best flexible manufacturing processes used to convert a sheet metal into required final shape using tool movement. In incremental sheet metal forming process, a single pointed forming tool is allowed to move over the sheet metal as per the pre-programmed numerical control of a computer. The advantage of making any complex part without die confirms its importance in the emerging automated industries. But this process has some limitations such as less formability and high surface roughness compared to the conventional forming process. Longer processing time is another drawback of the incremental sheet forming. This paper proposes a newly designed multi-point incremental forming (MPIF) tool to avoid the drawbacks faced by industry in increasing the formability and wall angle of the sheet metal with reduced time. The sheet metal stainless steel (SS) grade 430 has been used for forming process and the outputs obtained from MPIF and single point incremental forming (SPIF) have been compared with respect to wall angle, formability, surface roughness, spring back and forming time. Grey relational analysis (GRA) has been used to find the optimal value for the various responses obtained. The analysis of variance (ANOVA) calculation method has also been used to find the factors that influence the output responses. The responses obtained by the experiment have proved that the multipoint tool results better output. Page(s): 326-333