Machining-Induced Work Hardening Behavior of Inconel 718 Considering Edge Geometries

As a representative type of superalloy, Inconel 718 is widely employed in aerospace, marine and nuclear industries. The significant work hardening behavior of Inconel 718 can improve the service performance of components; nevertheless, it cause extreme difficulty in machining. This paper aims to investigate the influence of chamfered edge parameters on work hardening in orthogonal cutting of Inconel 718 based on a novel hybrid method, which integrates Coupled Eulerian-Lagrangian (CEL) method and grain-size-based functions considering the influence of grain size on microhardness. Orthogonal cutting experiments and nanoindentation tests are conducted to validate the effectiveness of the proposed method. The predicted results are highly consistent with the experimental results. The depth of work hardening layer increases with increasing chamfer angle and chamfer width, also with increasing feed rate (the uncut chip thickness). However, the maximum microhardness on the machined surface does not exhibit a significant difference. The proposed method can provide theoretical guidance for the optimization of cutting parameters and improvement of the work hardening.

Multi-Response Optimization of cutting parameters in MQL assisted Turning of Haynes 25 alloy with Taguchi based Grey Relational Analysis

Haynes 25 is a cobalt based superalloy gaining its importance in aerospace, heat treatment applications, chemical handling equipment, commercial gas turbine engines, bearing material, etc. This alloy is featured with low thermal conductivity, wear and corrosion resistance, strength with good resistance to oxidation at high temperatures. In the present study, optimization of process parameters in turning Haynes 25 alloy with uncoated and coated carbide tools under the minimum quantity lubrication (MQL) using Taguchi based grey relational analysis (GRA) method is attempted. The influence of cutting parameters and nano-particle concentration on surface roughness, tool wear, cutting and thrust forces are analyzed to improve the alloy machinability. The work also compares the responses obtained with uncoated and coated tool inserts and analyzes the effect of nano-particle concentration. Further, the experimental cutting and thrust forces are computed and validated using FE based DEFORM 3D software. The results obtained through simulation are in good accordance with experimental data within an average relative error of about 12 %.

Analysis and Optimization of cutting parameters of Carbon Steel EN8D used in the Shaft of Crawler Excavator under Carriage Track Roller Assembly for Model PC 200 - Review

Excavators are popular earthmoving vehicles that consists of a bucket, arm, rotating cab, and movable tracks. These components provide superior digging power and mobility, allowing this heavy equipment to perform a variety of functions. Currently, Industries which uses crawler excavators having Carbon Steel material for movable track roller are facing problem of strength, weight and high cost of track roller material and processes. Hence, selection of proper relevant material and its manufacturing processes will be done which could increase strength as well as decrease weight and overall cost of excavator under carriage track roller assembly parts. Thus, after suitable identification of materials and manufacturing process of track roller assembly parts, optimization and analysis will be done to confirm selected materials. In the present work, by using Taguchi approach, the turning of EN8D carbon steel is carried out in order to optimize the turning process parameters. The present paper deals with the optimization of selected process parameters, i.e., Speed, Feed rate, Depth of cut. Taguchi orthogonal array is designed with three levels of machining parameters and different experiments are done using L9 (3^3) orthogonal array. Taguchi method stresses the importance of studying the response variation using the signal to noise (S/N) ratio, resulting the minimization of quality characteristic variation due to uncontrollable parameter. Predicted value of cutting parameters and verification test values are valid when compared with the optimum value. It is found that optimum value of verification test is within the limits of predicted value and the objective of the work is full filled. Keywords: Crawler excavator, track roller, Taguchi method, Optimization, EN8D carbon steel, signal to noise (S/N) ratio etc.