scholarly journals Sustainable Lubrication Methods for the Machining of Titanium Alloys: An Overview

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3852 ◽  
Author(s):  
Enrique García-Martínez ◽  
Valentín Miguel ◽  
Alberto Martínez-Martínez ◽  
María Carmen Manjabacas ◽  
Juana Coello
Keyword(s):  
Titanium Alloys ◽  
Cutting Tool ◽  
Chemical Components ◽  
Thermal Gradients ◽  
Dry Machining ◽  
Machining Processes ◽  
Minimum Quantity ◽  
Modern Manufacturing ◽  
High Pressure Coolant ◽  
Very High

Titanium is one of the most interesting materials in modern manufacturing thanks to its good mechanical properties and light weight. These features make it very attractive for use in the aeronautical and aerospace industries. Important alloys, such as Ti6Al4V, are extensively used. Nevertheless, titanium alloys present several problems in machining processes. Their machinability is poor, affected by low thermal conductivity, which generates very high cutting temperatures and thermal gradients in the cutting tool. Lubricants and cutting fluids have traditionally been used to solve this problem. However, this option is unsustainable as such lubricants represent a risk to the environment and to the health of the operator due to their different chemical components. Therefore, novel, sustainable and green lubrication techniques are necessary. Dry machining is the most sustainable option. Nevertheless, difficult-to-machine materials like titanium alloys cannot be machined under these conditions, leading to very high cutting temperatures and excessive tool wear. This study is intended to describe, analyse and review the non-traditional lubrication techniques developed in turning, drilling and milling processes since 2015, including minimum quantity of lubricant, cryogenic lubrication, minimum quantity of cooling lubrication or high-pressure coolant. The aim is to provide a general overview of the recent advances in each technique for the main machining processes.

Solutions for Sustainable Machining

2016 ◽  
Author(s):  
Eckart Uhlmann ◽  
Bernd Peukert ◽  
Simon Thom ◽  
Lukas Prasol ◽  
Paul Fürstmann ◽  
...  
Keyword(s):  
Machine Tools ◽  
High Performance ◽  
Manufacturing Industry ◽  
Cutting Tool ◽  
The United States ◽  
Dry Machining ◽  
Machining Processes ◽  
Sustainable Machining ◽  
Sustainable Solutions ◽  
High Level

The manufacturing industry contributes over 19% to the world’s greenhouse gas emissions [1, 3] and 31% of the total energy consumed annually in the United States of America [2, 3]. There is therefore an increasing demand for sustainable solutions for the production technology industry. At the Technische Universitaet (TU) Berlin, Germany, a collaborative research center (CRC) is focusing on new solutions for the sustainable machining of high performance alloys, with developments from machine tools frames to cutting tool technology being undertaken. An innovative machine tool concept with a modular frame, which allows a high level of flexibility, has been developed. Furthermore, add-on upgrading systems for older machine tools, which are particularly relevant for developing countries, have been developed. These systems allow the accuracy of outdated machine tools to be increased, thus making the machine tools comparable to modern systems. Finally the cutting process also requires solutions for dry machining, as the use of cooling lubricant is environmentally damaging and a significant cost contributor in machining processes. Two solutions are being developed at the TU Berlin: an internally cooled cutting tool and a heating concept for ceramic tools to allow dry machining of high temperature alloys, for example for the aerospace industry.

Influence of Minimum Quantity Lubrication on Friction Coefficient and Work-Material Adhesion During Machining of Cast Aluminum With Various Cutting Tool Substrates Made of Polycrystalline Diamond, High Speed Steel, and Carbides

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Pierre Faverjon ◽  
Joël Rech ◽  
René Leroy
Keyword(s):  
Friction Coefficient ◽  
Aluminum Alloys ◽  
High Speed ◽  
Cutting Tool ◽  
High Speed Steel ◽  
Minimum Quantity Lubrication ◽  
Polycrystalline Diamond ◽  
Dry Machining ◽  
Minimum Quantity ◽  
Work Material

Due to the increasing emphasis on environmental constraints, industry works on how to limit the massive use of lubricants by using the micro-pulverization of oil in machining processes and, especially, in the machining of aluminum alloys for the automotive industry. The success of a machining operation is dependent on a friction coefficient and weak adhesion with the tool-work material interface. This paper aims at identifying the influence of cutting tool substrates (high speed steel (HSS), carbide, polycrystalline diamond (PCD)) and of minimum quantity lubrication (MQL) on the friction coefficient and on adhesion in tribological conditions corresponding to the ones observed in the cutting of aluminum alloys (sliding velocity: 20-1500 m/min). An open ball-on-cylinder tribometer, especially designed to simulate these tribological conditions through Hertz contact, has been used. It has been shown that HSS and carbide substrates lead to large friction coefficients (0.8–1) and substantial adhesion in dry conditions, whereas PCD substrates would lead to lower average friction coefficient values (0.4–0.5) and very limited adhesion, which proves the necessity of using PCD tools in the dry machining of aluminum. It has also been shown that the application of MQL leads to a large decrease of the friction coefficient (0.1–0.2) and eliminates almost all traces of adhesions on pins for any substrates, which shows that MQL is an interesting compromise between dry machining and flood cooling.

scholarly journals FEM and Analytical Modeling of the Incipient Chip Formation for the Generation of Micro-Features

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3789
Author(s):  
Michele Lanzetta ◽  
Marco Picchi Picchi Scardaoni ◽  
Armin Gharibi ◽  
Claudia Vivaldi
Keyword(s):  
Material Properties ◽  
Analytical Modeling ◽  
Cutting Tool ◽  
Sustainable Manufacturing ◽  
Cutting Parameters ◽  
Micro Machining ◽  
Machining Processes ◽  
Steel Alloys ◽  
Diamond Blade ◽  
Micro Features

This paper explores the modeling of incipient cutting by Abaqus, LS-Dyna, and Ansys Finite Element Methods (FEMs), by comparing also experimentally the results on different material classes, including common aluminum and steel alloys and an acetal polymer. The target application is the sustainable manufacturing of gecko adhesives by micromachining a durable mold for injection molding. The challenges posed by the mold shape include undercuts and sharp tips, which can be machined by a special diamond blade, which enters the material, forms a chip, and exits. An analytical model to predict the shape of the incipient chip and of the formed grove as a function of the material properties and of the cutting parameters is provided. The main scientific merit of the current work is to approach theoretically, numerically, and experimentally the very early phase of the cutting tool penetration for new sustainable machining and micro-machining processes.

Thermomechanical Fatigue Behavior of Bare and Coated CMSX-4

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
T. Coppola ◽  
S. Riscifuli ◽  
O. Tassa ◽  
G. Pasquero
Keyword(s):  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Turbine Blades ◽  
Thermomechanical Fatigue ◽  
Tensile Creep ◽  
Thermal Gradients ◽  
Test Program ◽  
Complete Set ◽  
Comparison Of The Results ◽  
Very High

Highly cooled turbine blades undergo very high thermal gradients during rapid engine idle-max-idle cycling. Traditional isothermal fatigue data are often insufficient for predicting service lives. A complete set of high temperature tests, in the range of 750–1050°C, was performed on single crystal alloy CMSX-4. The test program comprised tensile, creep, low cycle fatigue, and thermomechanical fatigue (TMF) tests. In particular the cycle time for TMF was 3 min, aiming to simulate the real high-power transient conditions in aircraft engines. Clockwise and counterclockwise diamond cycle types were applied on bare and coated specimens to investigate their influence on the fatigue limit. The comparison of the results obtained with the available ones from open literature is discussed.

scholarly journals Experimental Study of tool Wear Mechanisms in Conventional and High Pressure Coolant Assisted Machining of Titanium Alloy Ti17

2013 ◽  
Vol 554-557 ◽  
pp. 1961-1966 ◽  
Author(s):  
Yessine Ayed ◽  
Guenael Germain ◽  
Amine Ammar ◽  
Benoit Furet
Keyword(s):  
High Pressure ◽  
Titanium Alloy ◽  
Tool Wear ◽  
Titanium Alloys ◽  
Tool Life ◽  
Wear Mechanisms ◽  
Cutting Forces ◽  
Cutting Edge ◽  
Rake Face ◽  
High Pressure Coolant

Titanium alloys are known for their excellent mechanical properties, especially at high temperature. But this specificity of titanium alloys can cause high cutting forces as well as a significant release of heat that may entail a rapid wear of the cutting tool. To cope with these problems, research has been taken in several directions. One of these is the development of assistances for machining. In this study, we investigate the high pressure coolant assisted machining of titanium alloy Ti17. High pressure coolant consists of projecting a jet of water between the rake face of the tool and the chip. The efficiency of the process depends on the choice of the operating parameters of machining and the parameters of the water jet such as its pressure and its diameter. The use of this type of assistance improves chip breaking and increases tool life. Indeed, the machining of titanium alloys is generally accompanied by rapid wear of cutting tools, especially in rough machining. The work done focuses on the wear of uncoated tungsten carbide tools during machining of Ti17. Rough and finish machining in conventional and in high pressure coolant assistance conditions were tested. Different techniques were used in order to explain the mechanisms of wear. These tests are accompanied by measurement of cutting forces, surface roughness and tool wear. The Energy-dispersive X-ray spectroscopy (EDS) analysis technique made it possible to draw the distribution maps of alloying elements on the tool rake face. An area of material deposition on the rake face, characterized by a high concentration of titanium, was noticed. The width of this area and the concentration of titanium decreases in proportion with the increasing pressure of the coolant. The study showed that the wear mechanisms with and without high pressure coolant assistance are different. In fact, in the condition of conventional machining, temperature in the cutting zone becomes very high and, with lack of lubrication, the cutting edge deforms plastically and eventually collapses quickly. By contrast, in high pressure coolant assisted machining, this problem disappears and flank wear (VB) is stabilized at high pressure. The sudden rupture of the cutting edge observed under these conditions is due to the propagation of a notch and to the crater wear that appears at high pressure. Moreover, in rough condition, high pressure assistance made it possible to increase tool life by up to 400%.

Optimization of Control Gains in Numerical Control

2016 ◽  
Vol 1136 ◽  
pp. 651-654
Author(s):  
Hideki Aoyama ◽  
Duo Zhang
Keyword(s):  
Feed Rate ◽  
Machine Tools ◽  
Cutting Tool ◽  
Numerical Control ◽  
Machining Processes ◽  
Nc Program ◽  
Acceleration And Deceleration

It is frequently the case that the feed rate indicated in a numerical control (NC) program does not obtain in actual machining processes and the cutting tool does not path the points indicated in the NC. A reason underlying such problems is that control gains are not optimized, which causes issues with acceleration and deceleration in the control of machine tools. To address these problems, in this paper, we propose a method for the optimization of control gains using the MATLAB and Simulink software by considering the weight of the workpiece, the controlling distance, and the controlling speed. Simulations confirmed the effectiveness of our proposed optimization.

The Ledge Tool: A New Cutting Tool Insert

1985 ◽  
Vol 107 (2) ◽  
pp. 99-106 ◽  
Author(s):  
R. Komanduri ◽  
M. Lee
Keyword(s):  
Titanium Alloys ◽  
High Speed ◽  
Cutting Tool ◽  
Metal Removal ◽  
Face Milling ◽  
Cemented Carbide ◽  
Depth Of Cut ◽  
Peripheral Milling ◽  
Cemented Carbide Tool ◽  
Edge Wear

The salient features of a simple, wear-tolerant cemented carbide tool are described. Results are presented for high-speed machining (3 to 5 times the conventional speeds) of titanium alloys in turning and face milling. This tool, termed the ledge cutting tool, has a thin (0.015 to 0.050 in.) ledge which overhangs a small distance (0.015 to 0.060 in.) equal to the depth of cut desired. Such a design permits only a limited amount of flank wear (determined by the thickness of the ledge) but continues to perform for a long period of time as a result of wear-back of the ledge. Under optimum conditions, the wear-back occurs predominantly by microchipping. Because of geometric restrictions, the ledge tool is applicable only to straight cuts in turning, facing, and boring, and to face milling and some peripheral milling. Also, the maximum depth of cut is somewhat limited by the ledge configuration. In turning, cutting time on titanium alloys can be as long as ≈ 30 min. or more, and metal removal of ≈ 60 in.3 can be achieved on a single edge. Wear-back rates in face milling are about 2 to 3 times higher than in straight turning. The higher rates are attributed here to the interrupted nature of cutting in milling. Use of a grade of cemented carbide (e.g., C1 Grade) which is too tough or has too thick a ledge for a given application leads to excessive forces which can cause gross chipping of the ledge (rapid wear) and/or excessive deflection of the cutting tool with reduced depth of cut. Selection of a proper grade of carbide (e.g., Grades C2, C3, C4) for a given application results in uniform, low wear-back caused by microchipping. Because of the end cutting edge angle (though small, ≈ 1 deg) used, the ledge tool can generate a slight taper on very long parts; hence an N.C. tool offset may be necessary to compensate for wear-back. The ledge tool is found to give excellent finish (1 to 3 μm) in both turning and face milling. In general, conventional tooling with slight modifications can be used for ledge machining. The ledge tool can also be used for machining cast iron at very high speeds.

Sign in / Sign up

Export Citation Format

Share Document