scholarly journals Effect of tool wear on quality in drilling of titanium alloy Ti6Al4V, Part II: Microstructure and Microhardness

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Kallol Das ◽  
Mahdi Eynian ◽  
Anders Wretland
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
Surface Quality ◽  
Cutting Forces ◽  
Coolant Flow ◽  
Entry And Exit ◽  
Dry Cutting ◽  
Quality Issues ◽  
Titanium Alloy Ti6al4v

AbstractDrilling of Ti6Al4V with worn tools can introduce superficial and easily measured features such as increase of cutting forces, entry and exit burrs and surface quality issues and defects. Such issues were presented in the part I of this paper. In part II, subsurface quality alterations, such as changes of the microstructure and microhardness variation is considered by preparing metallographic sections and measurement, mapping of the depth of grain deformation, and microhardness in these sections. Drastic changes in the microstructure and microhardness were found in sections drilled with drills with large wear lands, particularly in the dry cutting tests. These measurements emphasize the importance of detection of tool wear and ensuring coolant flow in drilling of holes in titanium components.

Tool Wear Investigation on Dry Electrostatic Cooling in Turning Titanium Alloy Ti6Al4V

2010 ◽  
Vol 97-101 ◽  
pp. 2058-2061 ◽  
Author(s):  
Hui Wang ◽  
Rong Di Han ◽  
Yang Wang
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
Tool Life ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Cutting Fluid ◽  
Dry Cutting ◽  
Set Up ◽  
Titanium Alloy Ti6al4v ◽  
Emulsion Oil

The machinability of Titanium Alloy Ti6Al4V is poor, the traditional methods to machining is application of cutting fluids with the active additives which cause environmental pollution and health problems. In this paper, the dry electrostatic cooling was applied instead of cutting fluid for the aim of green cutting Ti6Al4V. The ionized device and gas supply system was set up, the effects of dry electrostatic cooling, emulsion oil and dry cutting on tool wear have been examined in turning of Ti6Al4V with carbide tools YG8, the curve between tool flank wear and cutting time was proposed, and the equation between cutting speed and tool life was set up. The results of experiments indicated that application of dry electrostatic cooling reduced the tool wear and increased the tool life. The research results show that clean production was achieved in metal cutting associated with dry electrostatic cooling.

scholarly journals Effect of tool wear on quality in drilling of titanium alloy Ti6Al4V, Part I: Cutting Forces, Burr Formation, Surface Quality and Defects

2017 ◽  
Vol 3 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Mahdi Eynian ◽  
Kallol Das ◽  
Anders Wretland
Keyword(s):  
Tool Wear ◽  
Surface Quality ◽  
Cutting Forces ◽  
Removal Rate ◽  
High Strength ◽  
Burr Formation ◽  
Workpiece Material ◽  
Wide Range ◽  
Titanium Alloy Ti6al4v ◽  
High Plastic

AbstractTitanium’s Ti6Al4V, alloy is an important material with a wide range of applications in the aerospace industry. Due to its high strength, machining this material for desired quality at high material removal rate is challenging and may lead to high tool wear rate. As a result, this material may be machined with worn tools and the effects of tool wear on machining quality need to be investigated. In this experimental paper, it is shown how drills of various wear levels affect the cutting forces, surface quality and burr formation. Furthermore, it is shown that high cutting forces and high plastic deformation, along with high temperatures that arise in cutting with worn tools may lead to initiation of microscopic cracks in the workpiece material in proximity of the drilling zone.

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%.

Monitoring of Cutting Conditions with Dry Cutting on CNC Turning Machine

2010 ◽  
Vol 443 ◽  
pp. 382-387 ◽  
Author(s):  
Somkiat Tangjitsitcharoen ◽  
Suthas Ratanakuakangwan
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Cutting Forces ◽  
Cutting Temperature ◽  
Cutting Conditions ◽  
Cutting Condition ◽  
Nose Radius ◽  
Dry Cutting ◽  
Cnc Turning ◽  
Coated Carbide

This paper presents the additional work of the previous research in order to verify the previously obtained cutting condition by using the different cutting tool geometries. The effects of the cutting conditions with the dry cutting are monitored to obtain the proper cutting condition for the plain carbon steel with the coated carbide tool based on the consideration of the surface roughness and the tool life. The dynamometer is employed and installed on the turret of CNC turning machine to measure the in-process cutting forces. The in-process cutting forces are used to analyze the cutting temperature, the tool wear and the surface roughness. The experimentally obtained results show that the surface roughness and the tool wear can be well explained by the in-process cutting forces. Referring to the criteria, the experimentally obtained proper cutting condition is the same with the previous research except the rake angle and the tool nose radius.

scholarly journals Analytical modelling of cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V

2014 ◽  
Vol 229 (6) ◽  
pp. 1122-1133 ◽  
Author(s):  
Yun Chen ◽  
Huaizhong Li ◽  
Jun Wang
Keyword(s):  
Titanium Alloy ◽  
Cutting Forces ◽  
Chemical Reactivity ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Analytical Modelling ◽  
Shear Instability ◽  
Published Data ◽  
Machining Processes ◽  
Titanium Alloy Ti6al4v

Titanium and its alloys are difficult to machine due to their high chemical reactivity with tool materials and low thermal conductivity. Chip segmentation caused by the thermoplastic instability is always observed in titanium machining processes, which leads to varied cutting forces and chip thickness, etc. This paper presents an analytical modelling approach for cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V. The catastrophic shear instability in the primary shear plane is assumed as a semi-static process. An analytical approach is used to evaluate chip thicknesses and forces in the near-orthogonal cutting process. The shear flow stress of the material is modelled by using the Johnson–Cook constitutive material law where the strain hardening, strain rate sensitivity and thermal softening behaviours are coupled. The thermal equations with non-uniform heat partitions along the tool–chip interface are solved by a finite difference method. The model prediction is verified with experimental data, where a good agreement in terms of the average cutting forces and chip thickness is shown. A comparison of the predicted temperatures with published data obtained by using the finite element method is also presented.

Experimental Investigation of Mechanical-Thermal Characteristics in High Efficiency Turning Titanium Alloy Ti6Al4V

2016 ◽  
Vol 836-837 ◽  
pp. 20-28
Author(s):  
Li Min Shi ◽  
Cheng Yang ◽  
Qi Jun Li
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
Cutting Force ◽  
High Efficiency ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Thermal Characteristics ◽  
Tool Failure ◽  
Minimal Quantity Lubrication ◽  
Titanium Alloy Ti6al4v

Titanium alloy Ti6Al4V has poor machinability, which leads to high unit cutting force and cutting temperature, rapid tool failure. In this study, the effect of the cutting speed, feed rate and cooling condition on cutting force and cutting temperature is critically analysed by turning experiment. At the same time, the relationship is established among tool wear, cutting force and cutting temperature. This investigation has shown that cutting speed is the decisive factor which increasing cutting force and cutting temperature. In the process of turning, tool wear results in high amounts of heat and mechanical stress, which leads to serious tool wear. The Minimal Quantity Lubrication reduces the frictional condition at the chip-tool, decreases cutting force and cutting temperature, and delays the tool failure.

scholarly journals An experimental research on the machinability of a high temperature titanium alloy BTi-6431S in turning process

2018 ◽  
Vol 5 ◽  
pp. 12
Author(s):  
Yanfeng Gao ◽  
Yongbo Wu ◽  
Jianhua Xiao ◽  
Dong Lu
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Tool Wear ◽  
Titanium Alloys ◽  
Cutting Forces ◽  
Shear Bands ◽  
Cutting Parameters ◽  
Aircraft Manufacturing ◽  
Mechanical And Physical Properties ◽  
Alpha Titanium

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.

Performance of Low Cost 3D Printed Minimum Quantity Lubrication Applicator Using Palm Oil in Milling Steel

2020 ◽  
Vol 997 ◽  
pp. 85-92
Author(s):  
Abang Mohammad Nizam Abang Kamaruddin ◽  
Abdullah Yassin ◽  
Shahrol Mohamaddan ◽  
Syaiful Anwar Rajaie ◽  
Muhammad Isyraf Mazlan ◽  
...  
Keyword(s):  
Tool Wear ◽  
Cutting Forces ◽  
Cutting Tool ◽  
Low Cost ◽  
Minimum Quantity Lubrication ◽  
Machining Process ◽  
Cutting Condition ◽  
Dry Cutting ◽  
Minimum Quantity ◽  
Tool Performance

One of the most significant factors in machining process or metal cutting is the cutting tool performance. The rapid wear rate of cutting tools and cutting forces expend due to high cutting temperature is a critical problem to be solved in high-speed machining process, milling. Near-dry machining such as minimum quantity lubrication (MQL) is regarded as one of the solutions to solve this problem. However, the function of MQL in milling process is still uncertain so far which prevents MQL from widely being utilized in this specific machining process. In this paper, the mechanism of cutting tool performance such as tool wear and cutting forces in MQL assisted milling is investigated more comprehensively and the results are compared in three different cutting conditions which is dry cutting, wet cutting (flooding) and MQL. The MQL applicator is constructed from a household grade low-cost 3D printing technique. The chips surface of chips formation in each cutting condition is also observed using Scanning Electron Microscopy (SEM) machine. It is found out that wet cutting (flooding) is the best cutting performance compare to MQL and dry cutting. However, it can also be said that wet cutting and MQL produced almost the same value of tool wear and cutting forces as there is negligible differences in average tool wear and cutting forces between them based on the experiment conducted.

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