Strength of Cutting Tool in Titanium Alloy Machining

2016 ◽  
Vol 685 ◽  
pp. 427-431 ◽  
Author(s):  
Victor Kozlov ◽  
Jia Yu Zhang
Keyword(s):  
Titanium Alloy ◽  
Cutting Force ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Edge ◽  
Contact Load ◽  
Internal Stresses ◽  
Compression Stress ◽  
Clearance Angle ◽  
Specific Contact

In this paper, contact conditions between cutting tool and work material, strength of cutting tool are analyzed. Experimental and theoretical studies of contact load distribution on the artificial flank wear-land that appears on the cutter in a free orthogonal turning disk of titanium alloy (Ti-6Al-2Mo-2Cr) are described. Calculations of internal stresses by the method of finite elements show that for the sharp cutter the main stresses into cutting wedge near to the cutting edge are compression stresses, very large (10 000 MPa) and exceed ultimate compression stress for cemented carbide. Decreasing of main stress with appearance of wear on the flank explains ability working of cutter even at large wear on the flank. Increasing of cutter’s break off probability with appearance of large wear on the flank is explained by increasing of zone where the internal stresses are large enough (more or equal 3 000 MPa) and increasing of defects probability into this zone, which serves as source of cracks. Abbreviation and symbols: m/s – meter per second (cutting speed v); mm/r – millimeter per revolution (feed rate f); MPa – mega Pascal (specific contact load as stress σ or τ); hf – the width of the flank wear land (chamfer) of the cutting tool, flank wear land can be natural or artificial like in this paper [mm]; xh – distance from the cutting edge on the surface of the flank wear land [mm]; σh – normal specific contact load on the flank land [MPa]; τh – shear (tangential) specific contact load on the flank land [MPa]; HSS – high speed steel (material of cutting tool); Py r – radial component of cutting force on the rake face [N]; Pz – tangential component of cutting force [N]; γ – rake angle of the cutting tool [°]; α – clearance angle of the sharp cutting tool [°]; αh – clearance angle of the flank wear land [°]; b – width of a machined plate or disk [mm]; σ-UTS - ultimate compression stress [MPa]; σUTS - ultimate tensile stress [MPa].

Influence of Chip Formation Characteristics on Flank Contact Load Distribution in Titanium Alloy Cutting

2015 ◽  
Vol 756 ◽  
pp. 126-131 ◽  
Author(s):  
Victor Kozlov ◽  
Xu Li
Keyword(s):  
Titanium Alloy ◽  
Chip Formation ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Thickness Ratio ◽  
Cutting Edge ◽  
Contact Load ◽  
Specific Contact

In this paper different contact conditions between tool, chip and work material are analyzed. Experimental and theoretical studies of contact load distribution on the artificial flank wear land of the cutter in free orthogonal turning of a disk made from titanium alloy (Ti-6Al-2Mo-2Cr) are described. Investigations of cutting with various feed rate and cutting speed show that the greatest contact loads are observed immediately at the cutting edge. It is associated with the discontinuous character of titanium alloy chip and the elastic recovery of the transient (machined) surface at the moment when generated chip element is separated. The main influence of the variable chip thickness ratio of the discontinuous chip on the value of the greatest normal contact load near the cutting edge is shown that confirms the author’ hypothesis about a sag of the transient surface in the cutting edge region.Abbreviation and symbols: m/s – meter per second (cutting speed v); mm/r – millimeter per revolution (feed rate f); MPa – mega Pascal (specific contact load as stress σ or τ); hf– the width of the flank wear land of the cutting tool, flank wear land can be natural or artificial like in this paper [mm]; xh– distance from the cutting edge on the surface of the flank wear land [mm]; σh– normal specific contact load on the flank land [MPa]; τh– shear (tangential) specific contact load on the flank land [MPa]; HSS – high speed steel (material of cutting tool); Py r– radial component of cutting force on the rake face [N]; Pz– tangential component of cutting force [N]; γ – rake angle of the cutting tool [°]; α – clearance angle of the sharp cutting tool [°]; αh– clearance angle of the flank wear land [°]; b – width of a machined plate or disk [mm]; a – the thickness of the layer being removed (uncut chip thickness) [mm]; a1– chip thickness [mm]; Ka– chip thickness ratio (Ka= a1/a) as a degree of plastic deformation in chip formation zone; Ka2– variable chip thickness ratio, Ka2= a2/a1, where а2– distance from the rake face surface of the chip to the contact point of two neighbouring elements of the chip [mm]; Φ – shear angle [°]; hd– value, which determines the depth of deformation, for an ordinary task it is equal to the thickness of the machined part or the radius r of the machined disk [mm]; q – intensity of loading in the chip formation region [MPa].

scholarly journals Influence of Cutting Tool Wear on Contact Stresses and Temperature Distribution in Titanium Alloy Machining

2017 ◽  
Vol 743 ◽  
pp. 252-257 ◽  
Author(s):  
Victor Kozlov ◽  
Jia Yu Zhang ◽  
Ekaterina Letshiner ◽  
Wen Ze Zhao
Keyword(s):  
Titanium Alloy ◽  
Temperature Distribution ◽  
Experimental Research ◽  
Contact Stress ◽  
Cutting Tool ◽  
Flank Wear ◽  
Contact Stresses ◽  
Cutting Edge ◽  
Normal Contact Stress ◽  
Normal Contact

This paper analyses the results of experimental research of contact stresses distribution over an artificial flank wear-land and temperature distribution in a cutting wedge in a free orthogonal turning of the disk made from titanium alloy (Ti-6Al-2Mo-2Cr) by a cutter with a sharp-cornered edge and with a rounded cutting edge. The investigation was carried out by the method of “split cutter” (sectional tool) and method of variable length of an artificial flank wear land. Experiments with variable feed rate and cutting speed show that in titanium alloy machining with a sharp-cornered cutting edge, the highest normal contact stress over the flank land (σh max = 3400…2200 MPa) is observed immediately at the cutting edge, and the curve has a horizontal region with a length of 0.2…0.6 mm. At larger distance from the cutting edge, the value of normal contact stress is dramatically reduced to 1100…500 MPa. The character of normal contact stresses for a rounded cutting edge is different: it is uniform and its value is approximately 2 times smaller as compared to machining with sharp-cornered cutting edge. In author’s opinion it is connected with generation of a seizure zone in chip formation region and explains working capacity of very worn-out cutting tools in machining titanium alloys. The results of experimental research of temperature distribution in the cutting tool wedge show that temperature reaches 1000 °С at essential wear over the flank surface. Such high value of temperature on the contact surface causes softening of work material, and explains the small value of tangential contact stresses (τh = 800…200 MPa) and reduction of normal contact stresses σh far from the cutting edge for a sharp-cornered cutting edge.

The Application of FEA in High-Speed Cutting Tool

2011 ◽  
Vol 314-316 ◽  
pp. 1258-1261
Author(s):  
Lian Qing Ji ◽  
Kun Liu
Keyword(s):  
Titanium Alloy ◽  
Cutting Force ◽  
High Speed ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Temperature ◽  
Material Model ◽  
Friction Model ◽  
High Speed Cutting ◽  
Key Technologies

The history and application of the FEA are briefly presented in this paper. Several key technologies such as the building of material model, the establishment of the chip - tool friction model as well as meshing are described. Taking the high-speed cutting of titanium alloy (Ti - 10V - 2Fe - 3Al) as an example , reasonable cutting tools parameters are determined by simulating the influences of cutting temperature, cutting force on the tools parameters using FEA.

Calculation of Contact Stresses during Titanium Alloy Cutting

2018 ◽  
Vol 769 ◽  
pp. 364-370
Author(s):  
Victor Kozlov ◽  
Jia Yu Zhang ◽  
Ying Bin Guo ◽  
Sai Kiran Sabavath
Keyword(s):  
Titanium Alloy ◽  
Feed Rate ◽  
Cutting Tool ◽  
Contact Stresses ◽  
Cutting Edge ◽  
Initial Time ◽  
Small Magnitude ◽  
Normal Contact Stress ◽  
Normal Contact ◽  
Flank Surface

The paper presents data about distribution of contact stresses on a rake surface and flank-land of a cutter in free orthogonal turning of a disk made from a titanium alloy (Ti-6Al-2Mo-2Cr). On the cutting edge of the bar blade, there is a normal force Nρ, directed perpendicularly to a transient surface, with a large magnitude of specific linear force qN r= 182.6 N/mm, but the tangential force on the cutting edge Fρis equal to zero. On the rake surface, there are uniformly distributed shear contact stresses with very small magnitude of τ ≈ const ≈ 25 MPa, irrespective of feed rate, which speaks about plastic character of the contact on the rake surface. The greatest normal contact stress on the rake surface σmax≈ 1009 MPa, irrespective of feed rate. The greatest magnitude of normal contact stresses on the flank surface chamfer near the cutting edge σh max= 3400-2200 MPa confirms the hypothesis about recovery of a transient surface sag after separation of a formed element of a chip, and explains increased wear of the cutting tool on the flank surface at initial time. Normal σhand shear τhcontact stresses on the flank surface chamfer are essentially diminish with a distance from the cutting edge. It explains working ability of the cutting tool even at very large wear on the flank surface (hf> 3 mm). Our experimental data allows calculating the components of cutting force and contact stresses on the rake and flank surfaces of cutting tools during titanium alloy (Ti-6Al-2Mo-2Cr) machining.

Cut-Forming: A New Method of Producing Wire

1977 ◽  
Vol 99 (1) ◽  
pp. 225-228 ◽  
Author(s):  
T. Hoshi ◽  
M. C. Shaw
Keyword(s):  
Cutting Force ◽  
Cutting Tool ◽  
Cutting Edge ◽  
New Method ◽  
Round Wire

A new method of making wire is discussed in which cutting and forming are combined into one process. A chip is first obtained by cutting a billet using a specially designed cutting tool. This chip immediately enters a circular die adjacent to the cutting edge of the tool and is forced past the orifice of the die by the cutting force. The chip leaving the orifice is in the form of a perfectly round wire.

A Numerical Study to Investigate the Influence of Edge Preparation in Vibration Assisted Machining

2018 ◽  
Author(s):  
Salman Pervaiz ◽  
Sathish Kannan ◽  
Wael Abdel Samad
Keyword(s):  
Cutting Forces ◽  
Small Amplitude ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Numerical Study ◽  
Cutting Tools ◽  
Cutting Edge ◽  
Internal Stresses ◽  
Machining Performance ◽  
Edge Preparation

In machining operation, cutting tool performs a central role towards the overall machining performance. A user from metal cutting community always look for better cutting tools that can enhance productivity by reducing tool wear and cost. Modification in the micro-geometry of cutting edge is termed as edge preparation, and it is performed to improve the machining performance by strengthening the cutting edge, reducing internal stresses of coating and lowering the edge chipping etc. Edge preparation has a controlling influence on the formation of deformation zones, cutting temperature, cutting forces and stresses at the cutting interface. Vibration assisted machining (VAM) concept is gaining fame in the metal cutting sector community for machining difficult-to-machine materials. In VAM, cutting tool moves with a small amplitude vibration instead of moving with a constant cutting velocity. This small amplitude vibrational movement provides better machining performance for difficult-to-cut brittle materials. The current numerical study utilized different edge prepared micro-geometries such as sharp edge, round edge and chamfer edge etc. cutting tools, and then these cutting tools were used in the numerical simulations of VAM. The study shows higher magnitude of cutting forces under VAM with tools with modified geometry. The study is beneficial for the metal cutting community and opens new areas of industrial applications.

Research on Wear Mechanisms while Turning Titanium Alloy TC4

2010 ◽  
Vol 97-101 ◽  
pp. 1845-1848
Author(s):  
Dong Liu ◽  
Wu Yi Chen ◽  
Hong Hai Xu ◽  
Xue Ke Luo
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
Cutting Force ◽  
Flank Wear ◽  
Aerospace Industry ◽  
Cutting Temperature ◽  
High Chemical ◽  
Adhesion Wear ◽  
Wear Tool ◽  
High Chemical Activity

Titanium alloys are widely used in aerospace industry due to their excellent mechanical properties. Because of their low thermal conductivity, high chemical activity, large friction coefficient and so on, such problems occur during the cutting process as high cutting temperature, large specific cutting force and serious tool wear, leading to low machining efficiency. The cutting force, forms of tool wear; wear mechanics were experimentally studied and analyzed while machining titanium alloy TC4 using carbide tools YS8 and YG8. The experimental results indicated that the tool wear of YG8 influenced cutting force not very remarkable when flank wear smaller than 0.25mm. But when the flank wear was bigger than 0.25mm, the cutting force increased rapidly with the flank wear increased. And the tool wear influenced the cutting force dramatically. The forms of tool wear during machining TC4 using carbide tool were adhesion wear, tool chipping and. The desquamation and chipping of tool caused by adhesion wear were the main reason of the tool failure.

Edge Preparation on Cutting Force, Cutting Temperature and Tool Wear for Hard Turning

2014 ◽  
Vol 800-801 ◽  
pp. 424-429
Author(s):  
Pei Rong Zhang ◽  
Zhan Qiang Liu
Keyword(s):  
Tool Wear ◽  
Cutting Force ◽  
Hard Turning ◽  
Flank Wear ◽  
Cutting Temperature ◽  
Cutting Edge ◽  
Crater Wear ◽  
Cutting Edge Preparation ◽  
Flank Face ◽  
Edge Preparation

The paper investigates the effects of cutting edge preparation on cutting force, cutting temperature and tool wear for hard turning. An optimized characterization approach is proposed and five kinds of cemented tools with different edge preparation are adopted in the simulations by DEFROM-2DTM. The results show that both the forces and cutting temperature on the rake face climb up and then declines with the increasing of factor K (Sγ/Sα). While the temperature on flank face decrease with the increasing of the factor K. When the cutting conditions are identical, flank wear reduces while crater wear exacerbates before easing with the increasing of the factor K. The simulation results will provide valuable suggestions for optimization of cutting edge preparation for hard turning in order to obtain excellent machining quality and longer tool life.

Performance evaluation of a tungsten carbide–based self-lubricant cutting tool

2016 ◽  
Vol 232 (10) ◽  
pp. 1825-1836 ◽  
Author(s):  
Ayyankalai Muthuraja ◽  
Selvaraj Senthilvelan
Keyword(s):  
Tungsten Carbide ◽  
Cutting Force ◽  
Tool Life ◽  
Solid Lubricant ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Tools ◽  
Chip Morphology ◽  
Machined Surface ◽  
Flank Surface

Tungsten carbide cutting tools with and without solid lubricant (WC-10Co-5CaF2 and WC-10Co) were developed in-house via powder metallurgy. The developed cutting tools and a commercial WC-10Co cutting tool were used to machine cylindrical AISI 1020 steel material under dry conditions. The cutting force and average cutting tool temperature were continuously measured. The cutting tool flank surface and chip morphology after specific tool life (5 min of cutting) were examined to understand tool wear. The flank wear of the considered cutting tools was also measured to quantify the cutting tool life. The surface roughness of the workpiece was measured to determine the machining quality. The developed cutting tool with solid lubricant (WC-10Co-5CaF2) generated 20%–40% less cutting force compared to that of the developed cutting tool without solid lubricant (WC-10Co). In addition, the finish of the workpiece surface improved by 16%–20% when it was machined by the solid lubricant cutting tool. The cutting tool with solid lubricant (WC-10Co-5CaF2) exhibited a 15%–18% reduction in flank wear. Curlier and smaller saw tooth chips were generated from the WC-10Co-5CaF2 cutting tool, confirming that less heat was generated during the cutting process, and the finish of the machined surface was also improved.

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