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

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%.

Author(s):  
E. O. Ezugwu ◽  
J. Bonney ◽  
W. F. Sales ◽  
R. B. da Silva

Usage of titanium alloys has increased since the past 50 years despite difficulties encountered during machining. In this study PCD tools were evaluated when machining Ti-6Al-4V alloy at high speed conditions under high pressure coolant supplies. Increase in coolant pressure tend to improve tool life and minimise adhesion of the work material on the cutting tool during machining. Adhesion can be accelerated by the susceptibility of titanium alloy to galling during machining.


2018 ◽  
Vol 5 ◽  
pp. 12
Author(s):  
Yanfeng Gao ◽  
Yongbo Wu ◽  
Jianhua Xiao ◽  
Dong Lu

Titanium alloys are extensively applied in the aircraft manufacturing due to their excellent mechanical and physical properties. At present, the α + β alloy Ti6Al4V is the most commonly used titanium alloy in the industry. However, the highest temperature that it can be used only up to 300 °C. BTi-6431S is one of the latest developed high temperature titanium alloys, which belongs to the near-α alloy group and has considerably high tensile strength at 650 °C. This paper investigates the machinability of BTi-6431S in the terms of cutting forces, chip formation and tool wear. The experiments are carried out in a range of cutting parameters and the results had been investigated and analyzed. The investigation shows that: (1) the specific cutting forces in the machining of BTi-6431S alloy are higher than in the machining of Ti6Al4V alloy; (2) the regular saw-tooth chips more easily formed and the shear bands are narrower in the machining of BTi-6431S; (3) SEM and EDS observations of the worn tools indicate that more cobalt elements diffuse into the workpiece from tool inserts during machining of BTi-6431S alloy, which significantly aggravates tool wear rate. The experimental results indicate that the machinability of BTi-6431S near alpha titanium alloy is significantly lower than Ti-6Al-4V alloy.


Author(s):  
Kaushalandra Patel ◽  
Guoliang Liu ◽  
Suril R. Shah ◽  
Tuğrul Özel

Abstract Micro-textures applied to cutting tool surfaces provide certain advantages such as reducing tool forces, stresses, and temperature hence overall friction between the tool–chip contact and improving chip adherence and associated tool wear. This study explores the effect of micro-texture geometry parameters fabricated on the rake face of tungsten carbide inserts that were tested in dry turning titanium alloy Ti-6Al-4V. The effects of micro-texture geometry on the cutting forces, tool stresses, tool temperatures, tool wear rate, and variable friction coefficient were studied with 3D finite element (FE) simulations. The simulation model was validated comparing cutting forces predicted and measured. The results indicated some effects of micro-textured tool geometry parameters being significant and others are not as significant. The experiments reveal that the effects of micro-groove width, depth, and distance from cutting edge are found to be significant on cutting forces, but the spacing is not as much. The effect of increasing feed rate on cutting force and tool wear was significant and suppressed the advantages offered by micro-grooved texture tool geometry. The simulation results indicate that the effect of micro-texture parameters such as groove depth and distance from cutting edge is significant on tool temperature and wear rate. The variable nature of friction coefficient was emphasized and represented as functions of state variables such as normal stress and local temperature as well as micro-texture parameters.


Author(s):  
A R Machado ◽  
J Wallbank

A high-pressure coolant system was used to machine Ti6Al4V and Inconel 901. A 14.5 MPajet of cutting fluid was applied against the chip flow at the rake face of the tool and this works as an efficient chip-breaker. Conventional overhead flood cooling was also used to establish a base for comparison. Chip control, cutting force, cutting temperature, chip-tool contact length, surface integrity, tool lives and wear mechanisms were studied. The high-pressure coolant system used improved tool lives significantly when machining the titanium alloy but it proved to be detrimental to tool lives when machining the nickel alloy.


2015 ◽  
Vol 45 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Mozammel Mia ◽  
Nikhil Ranjan Dhar

Hard turning of harder material differs from conventional turning because of its larger specific cutting forces requirements. The beneficial effects of hard turning can be offset by excessive temperature generation which causes rapid tool wear or premature tool failure if the brittle cutting tools required for hard turning are not used properly. Under these considerations, the concept of high-pressure coolant (HPC) presents itself as a possible solution for high speed machining in achieving slow tool wear while maintaining cutting forces at reasonable levels, if the high pressure cooling parameters can be strategically tuned. This paper deals with an experimental investigation of some aspects of the turning process applied on hardened steel (HRC48) using coated carbide tool under high-pressure coolant, comparing it with dry cut. The results indicate that the use of high-pressure coolant leads to reduced surface roughness, delayed tool flank wear, and lower cutting temperature, while also having a minimal effect on the cutting forces.


2016 ◽  
Vol 6 ◽  
pp. 154-159 ◽  
Author(s):  
Kamlesh Phapale ◽  
Sandip Patil ◽  
Swapnil Kekade ◽  
Shital Jadhav ◽  
Amit Powar ◽  
...  

2009 ◽  
Vol 618-619 ◽  
pp. 89-92 ◽  
Author(s):  
Suresh Palanisamy ◽  
Dean Townsend ◽  
M. Scherrer ◽  
Robert Andrews ◽  
Matthew S. Dargusch

Removal of heat from the cutting zone is critical when machining titanium. The application of high pressure coolant during turning of titanium results in longer tool life and better surface finish. In this paper, the effect of the application of cutting fluid at high pressure during the milling of titanium alloys is presented.


1970 ◽  
Vol 39 (2) ◽  
pp. 71-77 ◽  
Author(s):  
M Kamruzzaman ◽  
NR Dhar

To avoid surface distortion and to improve tool life, machining of alloy steel and other hard materials under high speed-feed condition requires instant heat transfer from the work-tool interface where the intensity of cutting temperature is the maximum. Conventional cooling is completely unable and other special techniques like MQL and cryogenic cooling are not suitable in context of product quality and cost effectiveness. Supply of high-pressure coolant (HPC) with high velocity may provide the best control to reduce cutting temperature and tool wear as well as increase tool life. This paper deals with an experimental investigation on the effect of high-pressure coolant on temperature, tool wear, surface roughness and dimensional deviation in turning 42CrMo4 steel by uncoated carbide inserts and comparing it with dry condition. It is observed that the cutting temperature and tool wear is reduced, tool life is increased, surface finish is improved, and dimensional deviation is decreased with the use of high-pressure coolant. Keywords: High-pressure coolant (HPC), Alloy steel, Temperature, Wear and Product quality. doi:10.3329/jme.v39i2.1849 Journal of Mechanical Engineering, Vol. ME39, No. 2, Dec. 2008 71-77


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