Machinability of the EBM Ti6Al4V in Cryogenic Turning

2015 ◽  
Vol 651-653 ◽  
pp. 1183-1188 ◽  
Author(s):  
Stefano Sartori ◽  
Alberto Bordin ◽  
Stefania Bruschi ◽  
Andrea Ghiotti
Keyword(s):  
Tool Wear ◽  
Liquid Nitrogen ◽  
Surface Integrity ◽  
Cutting Temperature ◽  
Chip Morphology ◽  
Cutting Fluid ◽  
Cobalt Chromium ◽  
Machined Surface ◽  
Surgical Implants ◽  
Cutting Zone

In machining operations, the adoption of a cutting fluid is necessary to mitigate the effects of the high temperatures generated on the cutting zone, and, therefore, to avoid severe detrimental effects on the tool wear and surface integrity. In the biomedical field, the traditional processes to manufacture surgical implants made of Titanium and Cobalt Chromium Molybdenum alloys involve turning and milling operations. To cool the cutting tool with standard oil emulsions leaves contaminants on the machined surfaces, which require further cleaning steps that are expensive in terms of time and costs. Currently, this limitation is marginally overcome by machining without the coolant; however, as a consequence, severe tool wear and poor surface integrity take place. In the last years, many studies have been conducted on the application of Liquid Nitrogen as a coolant in machining difficult-to-cut materials such as Ti6Al4V. Thanks to its properties to evaporate immediately when getting in contact with the cutting zone, thus living the workpiece and chips dry and clean other than its ability to lower the cutting temperature. The adoption of Liquid Nitrogen as a cooling mean in machining surgical implants may represent an optimum solution enhancing the benefits of dry machining. This work is aimed at evaluating the performances of the Liquid Nitrogen as a coolant in semi-finishing turning of Ti6Al4V produced by Electron Beam Melting, a comparison with dry turning is presented. The alloy machinability in such conditions is evaluated in terms of tool wear, machined surface integrity and chip morphology.

scholarly journals Effects of Tool Wear on Machined Surface Integrity During Milling of Inconel 718

2021 ◽  
Author(s):  
Liang Tan ◽  
Changfeng Yao ◽  
Dinghua Zhang ◽  
Minchao Cui ◽  
Xuehong Shen
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Tool Wear ◽  
Surface Integrity ◽  
Inconel 718 ◽  
Flank Wear ◽  
Cutting Temperature ◽  
Machined Surface ◽  
Tool Flank Wear ◽  
Machined Surface Integrity

Abstract This paper investigates the effects of tool wear on the machined surface integrity characteristics, including the surface roughness, surface topography, residual stress, microhardness and microstructure, during ball-end milling of Inconel 718. Tool wear, tool lifetime, and cutting force are measured. In addition, a two-dimensional finite element-based model is developed to investigate the cutting temperature distribution in the chip–tool–workpiece contact area. Results show that the ball nose end mill achieves tool lifetime of approximately 350 min. The cutting forces increase sharply with a greater tool flank wear width, while the highest cutting temperature has a decreasing tend at a flank wear width of 0.3 mm. Higher tool flank wear width produces larger surface roughness and deteriorative surface topography. A high-amplitude (approximately −700 MPa) and deep layer (approximately 120 mm) of compressive residual stress are induced by a worn tool with 0.3 mm flank wear width. The surface microhardness induced by new tool is larger than that induced by worn tool. Plastic deformation and strain streamlines are observed within 10 mm depth beneath the surface. The results in this paper provide an optimal tool wear criterion which integrates the surface integrity requirements and the tool lifetime for ball-end finish milling of Inconel 718.

A Study on the High Speed Face Milling of Ti-6Al-4V Alloy

Manufacturing ◽  
2002 ◽  
Author(s):  
Balkrishna Rao ◽  
Yung C. Shin
Keyword(s):  
Tool Wear ◽  
Surface Integrity ◽  
Experimental Analysis ◽  
High Speed ◽  
Numerical Study ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Face Milling ◽  
Machined Surface ◽  
Element Analysis

This paper is concerned with the experimental and numerical study of the high speed face milling of Ti-6Al-4V titanium alloy. Machining is carried out by uncoated carbide and polycrystalline diamond cutters in the presence of an abundant supply of coolant. Experimental analysis is conducted in terms of cutting forces, chip morphology, surface integrity and tool wear. The experimental analysis is supplemented by simulations from the finite element analysis where needed. The highest cutting speed realized for both the cutting tool materials is 600 sfpm with the diamond cutter operating at feeds lower than that for carbide. Good surface integrity in terms of residual stress and surface finish is achieved under the machining conditions used with limited tool wear. Residual stresses imparted to the machined surface are compressive with the diamond tool yielding higher values and are the most sensitive to feed. Tool wear patterns are described in terms of various cutting conditions.

An Investigation Into Machinability of Sintered Nanocrystalline Hydroxyapatite

2011 ◽  
Author(s):  
Sanket S. Kulkarni ◽  
Mark Haynes ◽  
Lorraine Reimers ◽  
Kaushik R. Achanta ◽  
Shuting Lei
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Surface Integrity ◽  
Cutting Forces ◽  
Chip Morphology ◽  
Optical Microscope ◽  
Machined Surface ◽  
Tissue Replacement ◽  
Nanocrystalline Hydroxyapatite ◽  
Machining Strategies

Close physical properties with human bone make sintered hydroxyapatite (HAP) a suitable bioceramic material for hard tissue replacement. When being used as implant devices in the human body, the HAP bioceramic needs to be machined to the closest possible configuration with minimal surface roughness. This study investigates the machinability of a newly developed, fully dense nanocrystalline hydroxyapatite (nHAP) bioceramic in turning operations. Efforts are focused on the effects of various machining conditions on surface integrity. Surface roughness is measured using a surface profilometer and the machined surface is observed using a scanning electron microscope (SEM). Chip morphology and tool wear are examined using an optical microscope. Cutting forces are measured using a three-component dynamometer. Based on the experimental results, it is found that the nHAP bioceramic is not very difficult to machine because the tool wear and cutting forces are small. However, the big challenge is how to obtain a smooth and strong surface without chipping or fracturing the material. Two machining strategies are proposed for improving the surface integrity of the sintered nHAP bioceramic in the future.

scholarly journals Influence of turning tool wear on the surface integrity and anti-fatigue behavior of Ti1023

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110112
Author(s):  
Li Xun ◽  
Wang Ziming ◽  
Yang Shenliang ◽  
Guo Zhiyuan ◽  
Zhou Yongxin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Plastic Deformation ◽  
Titanium Alloy ◽  
Fatigue Life ◽  
Tool Wear ◽  
Surface Integrity ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Machined Surface ◽  
Deformation Layer

Titanium alloy Ti1023 is a typical difficult-to-cut material. Tool wear is easy to occur in machining Ti1023, which has a significant negative effect on surface integrity. Turning is one of the common methods to machine Ti1023 parts and machined surface integrity has a direct influence on the fatigue life of parts. To control surface integrity and improve anti-fatigue behavior of Ti1023 parts, it has an important significance to study the influence of tool wear on the surface integrity and fatigue life of Ti1023 in turning. Therefore, the effect of tool wear on the surface roughness, microhardness, residual stress, and plastic deformation layer of Ti1023 workpieces by turning and low-cycle fatigue tests were studied. Meanwhile, the influence mechanism of surface integrity on anti-fatigue behavior also was analyzed. The experimental results show that the change of surface roughness caused by worn tools has the most influence on anti-fatigue behavior when the tool wear VB is from 0.05 to 0.25 mm. On the other hand, the plastic deformation layer on the machined surface could properly improve the anti-fatigue behavior of specimens that were proved in the experiments. However, the higher surface roughness and significant surface defects on surface machined utilizing the worn tool with VB = 0.30 mm, which leads the anti-fatigue behavior of specimens to decrease sharply. Therefore, to ensure the anti-fatigue behavior of parts, the value of turning tool wear VB must be rigorously controlled under 0.30 mm during finishing machining of titanium alloy Ti1023.

Study of the Effect of Tool Wear on Cutting Ti6Al4V Process

2013 ◽  
Vol 690-693 ◽  
pp. 2030-2035
Author(s):  
Shu Bao Yang ◽  
Hong Chao Ni ◽  
Guo Hui Zhu
Keyword(s):  
Tool Wear ◽  
Cutting Force ◽  
Cutting Temperature ◽  
Chip Morphology ◽  
Key Factors ◽  
Serrated Chip ◽  
Comprehensive Properties ◽  
Commercial Applications ◽  
On Chip ◽  
Rapid Tool

Ti6Al4V alloy is widely used in the aircraft industry, marine and the commercial applications due to its excellent comprehensive properties. However, its poor machinability prevents it from application widely, and the rapid tool wear is one of the key factors. The FEM models of cutting titanium alloy are established. The effect of tool wear on chip morphology, cutting temperature and cutting force are studied. The simulation results show that: the cutting force and cutting temperature will rise with the increase of tool wear. Furthermore, the degree of chip deformation will improve, but the frequency of serrated chip tooth occurred will decrease.

scholarly journals Effects of the Tribological Behaviour of h-BN MQL Nano Cutting Fluid (NCF-MQL) on Turning Inconel 625

2019 ◽  
Vol 11 (4) ◽  
pp. 107-121 ◽  
Author(s):  
Chinmaya PADHY ◽  
Pariniti SINGH
Keyword(s):  
Optimization Technique ◽  
Minimum Quantity Lubrication ◽  
Chip Morphology ◽  
Machining Process ◽  
Cutting Fluid ◽  
Inconel 625 ◽  
Machining Parameters ◽  
Machining Performance ◽  
Tribological Behaviour ◽  
Machined Surface

Minimum quantity lubrication (MQL) is currently a widely used lubricating technique during machining, in which minimum amount of lubricant in the form of mist is delivered to the machining interface, thus helps to reduce the negative effects caused to the environment and human health. Further, to enhance the productivity of machining process specifically for hard-to-cut materials, nano cutting fluid (suitably mixed nano materials with conventional cutting fluid) is used as an alternative method to conventional lubrication (wet) in MQL. In this study, h-BN nano cutting fluid was formulated with 0.1% vol. concentration of h-BN in conventional cutting fluid (Servo- ‘S’) for NCF-MQL technique and its tribological behaviors on machining(turning) performance of Inconel 625 were studied and compared with other lubricating conditions (dry, wet, MQL conventional). The tribological effects were analyzed in terms of tool wear analysis, chip morphology along with statistical analysis for machined surface and evolved cutting forces during machining. The optimal input machining parameters for experiments were defined by the use of Taguchi and Grey relational based multi response optimization technique. Finally, the tribological study shows that the use of h-BN NCF-MQL is a viable and sustainable option for improving machining performance of hard- to- cut material like Inconel 625.

Investigations on the Application of Minimum Quantity Solid Lubrication in Turning

2017 ◽  
Author(s):  
Mayur A. Makhesana ◽  
Kaushik M. Patel
Keyword(s):  
Tool Wear ◽  
Cost Effective ◽  
Solid Lubricants ◽  
Cutting Fluid ◽  
Solid Lubrication ◽  
Machining Processes ◽  
Machined Surface ◽  
Minimum Quantity ◽  
Set Up ◽  
Experimental Findings

Machining is the manufacturing process, capable of producing required shape and size by material removal. In recent times industries are striving to enhance the performance of machining processes. One of the problem associated with machining is the amount of heat generation as a result of friction between tool and workpiece. Heat generated may affect the quality of machined surface and tool wear. In order to control it, cutting fluid is applied in large quantity. The problem arises with the use of cutting fluid is its effect on worker’s health and environment. The present investigation is an attempt to explore the use the solid lubricants in machining as an alternative to cutting fluid. The work involves development of minimum quantity solid lubrication set up. Turning experiments has been performed by applying solid lubricants mixed with cutting fluid in minimum quantity. The performance of minimum quantity solid lubrication has been assessed in form of obtained surface finish, power consumption and tool wear during turning. Experimental findings discovered the superiority of minimum quantity solid lubrication over conventional cutting fluid and can be considered as cost effective and sustainable lubrication method.

Control of Machining Process for Titanium Alloy Based on Green Cooling and Lubricating Technology

2012 ◽  
Vol 580 ◽  
pp. 7-11
Author(s):  
Yue Zhang ◽  
Li Han ◽  
You Jun Zhang ◽  
Xi Chuan Zhang
Keyword(s):  
Titanium Alloy ◽  
Water Vapor ◽  
High Speed ◽  
Cutting Temperature ◽  
Small Diameter ◽  
Machining Process ◽  
Machined Surface ◽  
Cutting Zone ◽  
Cutting Experiments ◽  
Special Control

The machining process of titanium alloys always need special control by using coolant and lubricant as it is one of the difficult-to-cut materials. The cutting experiments are carried out based on green cooling and lubricating technology. To achieve green cutting of titanium alloy Ti-6Al-4V with water vapor cooling and lubricating, a minitype generator is developed. Compared to dry and wet cutting, the using of water vapor decreases the cutting force and the cutting temperature respectively; enhances the machined surface. And it can help to chip forming and breaking. Water vapor application also improves Ti-6Al-4V machinability. The excellent cooling and lubricating action of water vapor could be summarized that water molecule has polarity, small diameter and high speed, can be easily and rapidly to proceed adsorption in the cutting zone. The results indicate that the using of water vapor has the potential to attain the green cutting of titanium alloy.

Intensification of Finish Turning of Stainless Steels with the Use of Technological Cutting Fluids

2013 ◽  
Vol 371 ◽  
pp. 23-27
Author(s):  
Vadim Boguslavskiy ◽  
Tatiana Ivchenko ◽  
Viktor Polchenko ◽  
Iliya Navka
Keyword(s):  
Quantitative Estimation ◽  
Cutting Temperature ◽  
Cost Price ◽  
Cutting Fluid ◽  
Finish Turning ◽  
Cutting Zone ◽  
Definition Of ◽  
Cutting Regimes ◽  
The Cost ◽  
Further Development

The low workability of special brands corrosion-proof, heat resisting and high-resistance steels and alloys, widespread in details and nodes of modern machines, causes high labour input and the cost price of their manufacture. In this connection probes of possibilities of heightening of capacity and lowering of the cost price of handling of these materials at the expense of improvement of working conditions of the cutting instrument and, in particular, at the expense of application of various technological cutting fluid (TCF). High temperatures in a workpiece range, arising because of low heat conduction of intractable materials, define necessity of probe of the temperature phenomena for a cutting zone. The further development of a technique of definition of temperatures is of interest for these aspects of materials in a cutting zone at use ТСF and the account of their influence on a choice of optimum conditions of cutting. Researches of limitations on the roughness of the treated surface and cutting temperature are executed, in-use during optimization of cutting regimes at finish turning stainless materials, including with the use of technological cutting fluid. Analytical dependences of optimum cutting serve and speed from the parameters of finish turning process are set, providing the quantitative estimation of possibilities of the cutting regimes increase due to application of TCF. The estimation of efficiency of TCF application is executed on the basis of coefficient of increase of the treatment productivity.

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