Experimental Study on Surface Integrity, Dimensional Accuracy, and Micro-Hardness in Thin-Wall Machining of Aluminum Alloy

Author(s):  
Gururaj Bolar ◽  
Shrikrishna N. Joshi

This article presents an experimental investigation into the influence of process parameters viz. feed per tooth, axial depth of cut on milling force, surface finish, wall deflection and micro-hardness during thin-wall machining of an aerospace grade aluminum alloy 2024-T351. Results revealed that the process parameters significantly influence the surface finish and dimensional accuracy of machined thin-walls. High feed rate promoted the formation of built-up-edge (BUE). Combination of high feed and axial depth of cut aided in catastrophic failure of tools. Surface damages such as material plucking, material shearing, material adhesion and deformed feed mark layer formation were observed. Axial depth of cut negatively influenced the wall deflection leading to loss of dimensional accuracy. Interestingly, the micro-hardness at the machined surface was found to be lower than that of the bulk material hardness. These results will be useful in selection of suitable process parameters for quality and precise machining of thin-wall parts.

2021 ◽  
Vol 8 ◽  
pp. 17
Author(s):  
Gururaj Bolar ◽  
Shrikrishna Nandkishor Joshi

The selection of optimal process parameters is essential while machining thin-wall parts since it influences the quality of the product and affects productivity. Dimensional accuracy affects the product quality, whereas the material removal rate alters the process productivity. Therefore, the study investigated the effect of tool diameter, feed per tooth, axial and radial depth of cut on wall deflection, and material removal rate. The selected process parameters were found to significantly influence the in-process deflection and thickness deviation due to the generation of unfavorable cutting forces. Further, an increase in the material removal rate resulted in chatter, thus adversely affecting the surface quality during the final stages of machining. Considering the conflicting nature of the two performance measures, Non-dominated Sorting Genetic Algorithm-II was adopted to solve the multi-objective optimization problem. The developed model could predict the optimal combination of process variables needed to lower the in-process wall deflection and maintain a superior surface finish while maintaining a steady material removal rate.


2011 ◽  
Vol 264-265 ◽  
pp. 1124-1129 ◽  
Author(s):  
Ramesh Rudrapati ◽  
Pradip Kumar Pal ◽  
Asish Bandyopadhyay

Good surface finish is one of the important demands from the outputs of a cylindrical grinding machine. Also it is expected that dimensional accuracy, including accuracy in roundness, is fine in traverse cut cylindrical grinding. Now, like any other machine tool, cylindrical grinding machines also do vibrate, and vibration will affect accuracy and surface finish of the parts produced in grinding. The analysis of vibration in cylindrical grinding is then very much important. In the present study some aspects of vibration – behavior of cylindrical grinding machine have been experimented and analyzed. The process parameters have been varied and vibration signals have been measured in different directions by positioning an accelerometer at tail stock of the machine. The data have been analyzed through various statistical techniques to identify and predict vibration at given combinations of process parameters. The results and analysis of data give useful idea about dynamic performance of cylindrical grinding machine in traverse cut cylindrical grinding operation.


2021 ◽  
Vol 27 (4) ◽  
pp. 296-305
Author(s):  
Arpit Srivastava ◽  
Mukesh Kumar Verma ◽  
Ramendra Singh Niranjan ◽  
Abhishek Chandra ◽  
Praveen Bhai Patel

Abstract Aluminum alloy 7075-T651 is a widely used material in the aviation, marine, and automobile sectors. The wide application marks the importance of this material’s research in the manufacturing field. This research focuses on optimizing input process parameters of the turning process in the machining of Aluminum 7075-T651 with a tungsten carbide insert. The input machining parameters are cutting speed, feed, and depth of cut for the output response parameters cutting force, feed force, radial force, material removal, and surface roughness of the workpiece. For optimization of process parameters, the Taguchi method, with standard L9 orthogonal array, is used. ANOVA is applied to obtain signifi-cant factors and optimal combinations of process parameters.


2003 ◽  
Vol 125 (2) ◽  
pp. 289-296 ◽  
Author(s):  
E. Liasi ◽  
W. P. T. North

In this paper, an integrated model for a turning process (in the radial direction) is presented. Furthermore, properties of adaptive control and more specifically self-tuning regulators (STR) are discussed and a self-tuning regulator is designed based on LQG methods. The objective is to suppress the radial vibrations due to surface micro-hardness variations and hence improve the resulting surface finish. The effectiveness of the control system is evaluated by means of computer simulations—a case study is presented.


Author(s):  
J. Ma ◽  
Shuting Lei ◽  
Huaqi Lu

Titanium alloys are widely used in aerospace industry owing to excellent mechanical properties. While because of high chemical reactivity and low thermal conductivity, titanium alloys are classified as hard-to-cut materials. In this paper, Finite Element Method (FEM) is employed to conduct numerical investigation in the effects of milling process parameters (milling speeds, feed per tooth, and axial depth of cut) on three-dimensional (3D) high speed milling of Titanium alloy (Ti-6Al-4V). The tool material used is Carbide and Johnson-Cook plastic model is employed to model the workpiece due to its capability of modeling large strains, high strain rates, and temperature dependent visco-plasticity. Different milling speeds, feed per tooth, and axial depth of cut are used to explore the effects of the milling process parameters on the cutting temperature, cutting forces, and power required for machining. This model provides fundamental understanding of cutting mechanics of the 3D high speed milling of Titanium alloy (Ti-6Al-4V).


2011 ◽  
Vol 264-265 ◽  
pp. 1118-1123
Author(s):  
Pradip Kumar Pal ◽  
Asish Bandyopadhyay ◽  
Ramesh Rudrapati

Cylindrical grinding is an efficient and useful method of achieving good dimensional accuracy and fine finish. Very often one of the main objectives of grinding process is to obtain very good surface finish. The present investigation takes into account the effects of common grinding parameters on surface finish obtained in cylindrical grinding. The material selected is mild steel. The grinding wheel dimensions and its specification are kept in-varied. Grinding parameters like in-feed, longitudinal feed and work speed have been varied at several levels. Surface finish parameter (Ra) has been measured and noted for evaluation of surface finish, by using the instrument Talysurf. These data have been analyzed, interpreted and discussed in the context of varied conditions of cylindrical traverse cut grinding. Apart from identifying relationships between process parameters and surface finish through graphical presentations, a number of techniques (Full Factorial Design, Response Surface Methodology (RSM) and MATLAB) have been applied on the experimental data to arrive at some conclusive remarks. The paper effectively shows how selection of process parameters may yield desirable surface finish.


2016 ◽  
Vol 852 ◽  
pp. 255-259 ◽  
Author(s):  
B. Singaravel ◽  
Chimmalagi Marulaswami ◽  
Thangiah Selvaraj

Turning is one of the fundamental machining operations and its process parameters leads to better machining performance. The economic benefit of turning operation is providing components with appropriate dimensional accuracy. In this work, the effects of process parameters on dimensional accuracy (circularity and cylindricity) parameters are analyzed in turning of EN25 steel. The process parameters considered are cutting speed, feed rate and depth of cut in order to minimize circularity and cylindricity. The result revealed that the minimum dimensional accuracy error values such as circularity and cylindricity are obtained in the combination of higher value of cutting speed and lower value of feed rate and depth of cut. This analysis is used to meet the machined work piece within the tolerance limit and improve the quality criteria.


2021 ◽  
Vol 9 ◽  
Author(s):  
Anis Fatima ◽  
◽  
Muhammad Wasif ◽  
Muhammad Omer Mumtaz ◽  
◽  
...  

Metal cutting operations involve intense heat generation owing to plastic deformation of the work piece and due to friction at the tool-work piece and tool-chip interface. The heat generated in metal cutting unfavourably affects the quality and thus the functional performance of the product. It is known that quality and functional performance is the function of roughness and dimensional accuracy. To maintain a longer component life, along with the robust material choice, a component should have good surface finish and dimensional accuracy. While, for the organization to monitor and control their environmental issues in a holistic manner, emphasis in adopting eco-friendly practices and protecting environment has been growing continuously across all the business sectors. In this study, an attempt is made to optimize the process parameter of stainless steel AISI-410 alloy, a nuclear graded material, for better surface finish. For this, Taguchi L9 orthogonal array was utilise to identify the process parameter and cutting environment. Analysis of variance (ANOVA) was also conducted to highlight the significant parameter that affects the surface finish most. A statistical model to forecast the surface roughness was also developed and was validated by an experiment with a maximum error of 12%. Results indicates that feed rate is the most critical factor that effects the surface roughness with the contribution of 91.5%, followed by environment with 5.22% contribution, cutting speed and depth of cut with 2.7 % and 0.4 % respectively. The correlation coefficient of 0.9213 and conformation tests reveals that developed statistical model predicts surface roughness with the statistical error limit.


2017 ◽  
Vol 23 (5) ◽  
pp. 845-857 ◽  
Author(s):  
Parlad Kumar Garg ◽  
Rupinder Singh ◽  
IPS Ahuja

Purpose The purpose of this paper is to optimize the process parameters to obtain the best dimensional accuracy, surface finish and hardness of the castings produced by using fused deposition modeling (FDM)-based patterns in investment casting (IC). Design/methodology/approach In this paper, hip implants have been prepared by using plastic patterns in IC process. Taguchi design of experiments has been used to study the effect of six different input process parameters on the dimensional deviation, surface roughness and hardness of the implants. Analysis of variance has been used to find the effect of each input factor on the output. Multi-objective optimization has been done to find the combined best values of output. Findings The results proved that the FDM patterns can be used successfully in IC. A wax coating on the FDM patterns improves the surface finish and dimensional accuracy. The improved dimensional accuracy, surface finish and hardness have been achieved simultaneously through multi-objective optimization. Research limitations/implications A thin layer of wax is used on the plastic patterns. The effect of thickness of the layer has not been considered. Further research is needed to study the effect of the thickness of the wax layer. Practical implications The results obtained by the study would be helpful in making decisions regarding machining and/or coating on the parts produced by this process. Originality/value In this paper, multi-objective optimization of dimensional accuracy, surface roughness and hardness of hybrid investment cast components has been performed.


2015 ◽  
Vol 830-831 ◽  
pp. 112-115 ◽  
Author(s):  
Anil Kumar Jain ◽  
Kasala Narasaiah ◽  
Shibu Gopinath

In present scenario most of airframe components employ aluminum alloy materials having wall thickness of 1.2 to 3mm. With advancement of manufacturing techniques such as high speed machining, it is possible to machine components with wall/floor thickness up to 0.3 to 0.5 mm with high aspect ratio. The aim of making such parts is to reduce weight of payload. The machining of monolithic structure involves removing of material up to 95% from the raw material. The objective of the study is to achieve maximum material removal rate without compromise on geometry, dimensional accuracy while machining the part. This paper proposes a working methodology for high speed machining which includes efficient process planning, based on static and dynamic analysis. This paper provides insight knowledge of selection of cutting tool, fixture design, clamping method, cutting process parameters; machine tool and computer aided manufacturing (CAM) strategy, optimum stock for minimal bending and distortion. This technology has been demonstrated in hexagonal test specimen of 0.5 mm thin wall and also proven on the indigenous developed global positioning system (GPS) components.


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