Minimal quantity cooling lubrication in turning of Ti6Al4V: Influence on surface roughness, cutting force and tool wear

2015 ◽  
Vol 231 (9) ◽  
pp. 1542-1558 ◽  
Author(s):  
Salman Pervaiz ◽  
Ibrahim Deiab ◽  
Amir Rashid ◽  
Mihai Nicolescu
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Titanium Alloys ◽  
Cutting Force ◽  
Tool Life ◽  
Heat Dissipation ◽  
Elevated Temperatures ◽  
Chemical Reactivity ◽  
Machining Performance ◽  
Minimal Quantity

Titanium alloys generally show low machinability ratings. They are referred as difficult-to-cut materials due to their inherent properties such as low thermal conductivity, high chemical reactivity and high strength at elevated temperatures. Cooling strategies play an important role to improve the machining performance of the cutting process. In order to facilitate the heat dissipation from the cutting zone, generous amount of coolant is used when machining highly reactive metals such as titanium alloys. Generally, cutting coolants are nominated as pollutants due to their non-biodegradable nature. This article presents experimental evaluation of a minimal quantity cooling lubrication system. The study investigates a combination of sub-zero-temperature air and vegetable oil–based mist as possible environmentally benign alternative to conventional cooling methods. The results are compared with the dry and flood cutting environments as well. Machinability was evaluated experimentally by considering the surface finish, cutting forces, tool life and their associated tool wear mechanisms. It was concluded from the results obtained from the surface roughness, cutting force and tool life investigation that minimal quantity cooling lubrication (internal) cooling strategy has encouraging potential to replace the conventional flood cooling method.

Performance of Brazed Carbide End Mill Tool for Machining of Ti6Al4V

2014 ◽  
Vol 541-542 ◽  
pp. 363-367 ◽  
Author(s):  
Saad Nawaz ◽  
Li Xiao Xing ◽  
Zhou Chai
Keyword(s):  
Tool Wear ◽  
Titanium Alloys ◽  
Tool Life ◽  
Thermal Stresses ◽  
Elevated Temperatures ◽  
Aerospace Industry ◽  
Cutting Speed ◽  
Weight Ratio ◽  
Depth Of Cut ◽  
End Mill

Titanium alloys are attractive materials for aerospace industry due to their exceptional strength to weight ratio that is maintained at elevated temperatures and their good corrosion resistance. Major applications of Titanium alloys were military aerospace industry, but since last decade the trend has now shifted towards commercial industry. On the other hand Titanium alloys are notorious for being poor thermal conductor that leads to them being difficult materials for machining. In this experimental study brazed carbide end mill of grade 5 is used for rough down milling of Ti6Al4V for large depth of cut under different combinations of parameters and application of high pressure coolant. The machining performance was evaluated in terms of tool wear, tool life, thermal crack and tool breaking. The tool wear was mostly observed at the tool tip and at bottom part of tool thermal cracks were observed which propagated with respect to time. Flank wear due to scratching of the cutting chips and diffusion wear because of high thermal stresses were observed specially at the bottom of the cutting tool. At cutting speed of 38m/min tool wear couldnt be observed due to tool failure because of fracture under high thermal stresses. It was found that maximum tool life is obtained at the speed of 25m/min, feed rate of 150mm/min and depth of cut of 10mm. In the end it was concluded that machining of Ti6Al4V is a thermally dominant process which leads to high thermal stresses in machining zone that results in increasing tool wear rate and fracture propagation.

scholarly journals Theoretical and Experimental Investigation Into The Machining Performance in Axial Ultrasonic Vibration–Assisted Cutting of Ti6Al4V

2021 ◽  
Author(s):  
He Sui ◽  
Lifeng Zhang ◽  
Shuang Wang ◽  
Zhaojun Gu
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Influencing Factors ◽  
Ultrasonic Vibration ◽  
Tool Life ◽  
Feed Rate ◽  
Rotation Speed ◽  
Machining Parameters ◽  
Machining Performance ◽  
Cutting Depth

Abstract Axial ultrasonic vibration-assisted cutting (AUVC) has proved to have better machining performance compared with conventional cutting methods; however, the effect of numerous and complex influencing factors on machining performance has not been clearly revealed and a recommended combination of cutting conditions has not been proposed yet, especially for difficult-to-machine material such as Ti6Al4V alloy. This paper focuses on experimental and theoretical investigation into machining performance when cutting Ti6Al4V with the AUVC method. First, a retrospective of the separation characteristics of AUVC is provided and the variable parameter cutting characteristics are demonstrated. We classify the influencing factors on machining performance into four categories: machining parameters, vibration parameters, tool choice, and cooling conditions. The relationship between these factors in terms of their effect on machining performance is established theoretically. Then, it describes experiments to determine the influence of these factors on cutting force, tool life, and surface roughness. For absolute influence, the orders for cutting force, tool life, and surface roughness are respectively cutting depth > amplitude > feed rate > rotation speed, rotation speed > feed rate > amplitude > cutting depth, and feed rate > amplitude > cutting depth > rotation speed. However, for relative influence, the order is unified as: amplitude > feed rate > rotation speed > cutting depth. Finally, it suggests a smaller feed rate, larger amplitude, moderate rotation speed, and smaller cutting depth in addition to a WC tool coated with TiAlN and used under HPC cooling condition for optimal performance of AUVC. This recommendation is based on the theoretical analysis and experimental results of cutting force, surface roughness, and tool life.

Experimental Investigation of the Tool Wear and Tool Life in Micro Hard Milling

2013 ◽  
Author(s):  
Shreyas Shashidhara ◽  
Xinyu Liu ◽  
Weihang Zhu ◽  
James Curry ◽  
Victor Zaloom
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Abrasive Wear ◽  
Cutting Force ◽  
Tool Life ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Dry Machining ◽  
Edge Chipping ◽  
Edge Radius

The objective of this project is to experimentally investigate the influence of Minimum Quantity Lubrication (MQL) on tool wear and tool life in micro hardmilling. The experiments were performed on stainless steel using uncoated WC micro-mill with the nominal diameter of 508 microns. The tool wear is characterized by the volume of the material loss at the tool tip. In order to reveal the progression of the tool wear, the worn tool was examined periodically under SEM after a fixed amount of workpiece material removal (1.25 mm3 or 5 slots in this study). The tool life was characterized as the amount of material removed, instead of the conventional cutting times. The feedrate and the spindle speed were fixed, and two levels of axial depth of cut (50 and 75 microns) were compared. The higher depth of cut leads to longer tool life. The machining performance under MQL is superior to the dry machining for both process conditions in terms of the tool life. The cutting forces in feed direction and the surface roughness at the bottom of the slots were also examined during the experiments. The magnitude of the machining forces showed cyclic pattern for both MQL and dry machining. The SEM images and the cutting force signals suggested that the dominant mode of the tool wear in micro-milling is edge chipping and abrasive wear at the tool tip. The loss of the micro-grain of WC at the cutting edge leads to edge chipping, which reduces the effective cutting diameter; the abrasive wear enlarge the edge radius, causing the cutting force increase. As the cutting edge radius reaches a certain dimension, the whole edge was stripped off, a new edge formed with a smaller edge radius, and the cycle restarts. Under MQL cutting conditions, three cycles were observed before tool failure, while under dry machining conditions, the tool only experienced two cycles before tool breakage. The surface roughness at the bottom of the slots improved significantly with the application of MQL for all levels of the tool wear. The surface roughness did not increase drastically as the tool wear increased. It reached a plateau after the tool wear went into gradual wear state. Further experiments and theoretical analysis will be pursued in the future to gain a deeper understanding of tool wear mechanism in micro-milling.

Rotary Ultrasonic Machining of Titanium Alloy: A Feasibility Study

2005 ◽  
Author(s):  
N. J. Churi ◽  
Z. C. Li ◽  
Z. J. Pei ◽  
C. Treadwell
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Titanium Alloy ◽  
Tool Wear ◽  
Titanium Alloys ◽  
Cutting Force ◽  
Aerospace Industry ◽  
Ultrasonic Machining ◽  
Rotary Ultrasonic Machining ◽  
Conventional Machining

Due to their unique properties, titanium alloys are attractive for some unique applications especially in the aerospace industry. However, it is very difficult to machine these materials cost-effectively. Although many conventional and non-conventional machining methods have been reported for machining them, no reports can be found in the literature on rotary ultrasonic machining of titanium alloys. This paper presents an experimental study on rotary ultrasonic machining of a titanium alloy. The tool wear, cutting force, and surface roughness when rotary ultrasonic machining of the titanium alloy have been investigated using different tool designs and machining conditions. The results are compared with those when machining the same material with diamond grinding.

scholarly journals Experimental Investigation on Machinability of Titanium Alloy by Laser-Assisted End Milling

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1552
Author(s):  
Dong-Hyeon Kim ◽  
Choon-Man Lee
Keyword(s):  
Surface Roughness ◽  
Experimental Investigation ◽  
Titanium Alloy ◽  
Titanium Alloys ◽  
Cutting Force ◽  
Cutting Tool ◽  
End Milling ◽  
Chemical Reactivity ◽  
Depth Of Cut ◽  
Laser Assisted Machining

The Machining of titanium alloys is challenging because of their high strength, low thermal conductivity, high chemical reactivity, and high stresses at the cutting tool edges. Laser-assisted machining is an effective way to improve the machinability of titanium alloys. This paper presents an experimental investigation of the machinability of cutting force and surface roughness in laser-assisted end milling of titanium alloy Ti-6Al-4V. The absorptivity of Ti-6Al-4V was determined by conducting preheating experiments using a high-power diode laser with a wavelength of 940–980 nm. A thermal analysis was performed using the finite element method to predict temperature distribution. The depth of cut was determined where tensile strength decreased sharply, and the predicted surface temperature is presented in the analysis results. The experiments were performed with conventional machining and laser-assisted machining. Surface roughness, tool wear, and cutting force were evaluated. In contrast to the results of conventional end milling, laser-assisted end milling improved surface roughness. Moreover, laser-assisted end milling proved more effective than conventional end milling in terms of cutting tool damage. Our results proved that heat assistance significantly influenced the magnitude of the cutting forces—while the actual reduction in forces varied slightly depending on the force component, cutting tool, and cutting conditions, force components showed a reduction of roughly 13–46%.

scholarly journals Comparative assessment of hard turning under dry and minimum quantity lubrication

2021 ◽  
Vol 1206 (1) ◽  
pp. 012007
Author(s):  
Avez Shaikh ◽  
Ajinkya Shinde ◽  
Satish Chinchanikar ◽  
Guruprasad Zagade ◽  
Sonia Pardeshi
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Tool Life ◽  
Hard Turning ◽  
Cutting Speed ◽  
Comparative Assessment ◽  
Depth Of Cut ◽  
Machining Performance ◽  
Dry Cutting ◽  
Optimal Surface

Abstract Hard turning with CBN and ceramic inserts is commonly regarded as a cost-effective alternative to grinding. However, there have been few studies comparing hard turning with low-cost carbide tools to high-cost CBN and ceramic cutting tools. However, when it comes to the usage of cutting coolant during severe turning, there are mixed outcomes. In this study, a PVD-coated TiSiN-TiAlN carbide tool was used to hard turn AISI 52100 steel in a dry and MQL environment. Through multi-objective optimization, a comparative assessment in terms of surface roughness, cutting force, and tool life under various cutting settings is provided. In terms of three components of cutting force, surface roughness, and tool life, mathematical models were constructed to forecast and improve machining performance. Under both dry and MQL conditions, the study discovered an optimal cutting speed of 108 m/min, a feed value of 0.09 mm/rev, and a depth of cut of 0.16 mm. Under MQL, hard turning produced optimal surface roughness and tool life of 0.88 m and 64 minutes, respectively. In comparison to hard turning under dry cutting, the optimal surface roughness was 1.07 m and the tool life was 49 minutes. Under MQL, tool life increased by over 31%, according to the findings of the experiments. Under dry and MQL conditions, however, no significant differences in cutting forces and surface roughness were identified.

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%.

Dry Machining of Inconel 825 Superalloys

2021 ◽  
Vol 11 (4) ◽  
pp. 26-39
Author(s):  
Kshitij Pandey ◽  
Saurav Datta
Keyword(s):  
Tool Wear ◽  
Surface Morphology ◽  
Cutting Force ◽  
Carbide Tool ◽  
Dry Machining ◽  
Machining Performance ◽  
Force Magnitude ◽  
Wear Pattern ◽  
Inconel 825

The present work investigates application feasibility of PVD TiN/TiCN/TiN coated cermet and CVD Al2O3/TiCN coated SiAlON for dry machining of Inconel 825 superalloy. Machining performance is interpreted through cutting force magnitude, tool-tip temperature, and mechanisms of tool wear. Results are compared to that of CVD multi-layer TiN/TiCN/Al2O3/TiN coated WC-Co tool. It is evidenced that SiAlON tool generates lower cutting force but experiences higher tool-tip temperature than other two counterparts. Apart from abrasion and adhesion, carbide tool witnesses coating peeling and ploughing. In contrast, SiAlON tool suffers from inexorable chipping and notching. Wear pattern of cermet tool seems less severe than carbide and SiAlON. Chip's underside surface morphology appears relatively better in case of cermet tool.

Investigation on the Tool Wear Model and Equivalent Tool Life in End Milling Titanium Alloy Ti6Al4V

2018 ◽  
Author(s):  
Kai Guo ◽  
Bin Yang ◽  
Jie Sun ◽  
Vinothkumar Sivalingam
Keyword(s):  
Tool Wear ◽  
Titanium Alloys ◽  
Tool Life ◽  
End Milling ◽  
Cutting Speed ◽  
Carbide Tool ◽  
Wear Model ◽  
Wear Process ◽  
Coated Carbide Tool ◽  
Coated Carbide

Titanium alloys are widely utilized in aerospace thanks to their excellent combination of high-specific strength, fracture, corrosion resistance characteristics, etc. However, titanium alloys are difficult-to-machine materials. Tool wear is thus of great importance to understand and quantitatively predict tool life. In this study, the wear of coated carbide tool in milling Ti-6Al-4V alloy was assessed by characterization of the worn tool cutting edge. Furthermore, a tool wear model for end milling cutter is established with considering the joint effect of cutting speed and feed rate for characterizing tool wear process and predicting tool wear. Based on the proposed tool wear model equivalent tool life is put forward to evaluate cutting tool life under different cutting conditions. The modelling process of tool wear is given and discussed according to the specific conditions. Experimental work and validation are performed for coated carbide tool milling Ti-6Al-4V alloy.

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