NSM Influence of PCBN Tool Edge Preparation in Orthogonal Hard .pdf by liningnvp

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									                                                                                     ERC
                                                                                     NSM

Influence of PCBN Tool Edge Preparation
  in Orthogonal Hard Turning – A Finite
            Element Analysis
                             By
                    Professor Taylan Altan
                       Ibrahim Al-Zkeri
                         Luca D’Anna

       Engineering Research Center for Net Shape Manufacturing
                       The Ohio State University
                     339 Baker Systems Building
                 1971 Neil Ave., Columbus, Ohio 43210
                            www.ercnsm.org

                          July 18, 2006
                                                                                                       1
                    High Performance Machining        Copyright © ERC/NSM 2006. All rights reserved.
                                                                                    ERC
                              Outline
                                                                                    NSM
1.   Introduction
        Hard Turning Process
        Effect of Edge Preparation and Cutting Conditions in Hard Turning
        Surface Integrity in Hard Turning
        Finite Element Modeling of Machining

2.   Objectives

3.   Research Approach

4.   Modeling Results

5.   Summary and Discussion

6.   Future Outlook

                                                                                                      2
                       High Performance Machining    Copyright © ERC/NSM 2006. All rights reserved.
                                                                                            ERC
                 Introduction – Hard Turning Process
                                                                                            NSM
                                   Hard Turning
     Hard Turning is defined as machining of parts with hardness above about RC 45

Since 1980s, the hard machining technology
has been applied in mechanical finishing of
hardened components such as:
• transmission shafts, bearings, gears and cams
  for the automotive industry
• landing gear struts for the aerospace industry
• Dies and molds for a variety of applications

It offers many benefits:
• multiple operations in a single setup;
• lower equipment costs;
• shorter setup time;
• high material removal rate (4~6 times)
  compared to grinding;
• improved surface integrity;
• easier waste management.
                                                                                                              3
                                                                                        [Dawson, 2002]
                                High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
                                                                                        ERC
              Introduction – Hard Turning Process
                                                                                        NSM
                           Orthogonal Cutting
Orthogonal cutting is a tool for understanding the fundamentals of hard turning.




                             Plane Strain Conditions




                                                                                     [Kerk, 1999]




                                                                                                          4
                            High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
                                                                                ERC
           Introduction – Hard Turning Process
                                                                                NSM
                  Tool Edge Preparation




Tungsten          Cubic Boron
 Carbide            Nitride




                                                                                                  5
                    High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
         Introduction – Effect of Edge Preparation and                                        ERC
                      Cutting Conditions                                                      NSM
                 Effect on Cutting Forces (Experimental Data)

                        Cutting speed = 93 m/min




Process: Orthogonal Cutting (Disc)
                                                       Rake Angle = -15°
Workpiece: AISI 52100 (60 HRC)
Cutting Tool: low-CBN
Feed Rate = 0.0762 mm/rev
Edge hone: Sharp                                                        [Kountanya, 2005]                  6
                            High Performance Machining    Copyright © ERC/NSM 2006. All rights reserved.
                                                                                      ERC
  Introduction – Residual Stresses in Hard Turning
                                                                                      NSM
Effect of Cutting Tool Edge Geometry (Experimental Data)
Process: bar turning                Feed: 0.15 mm/rev
Workpiece: AISI 52100 (57 HRC)      Depth of cut: 0.254 mm
Cutting tool: low-CBN               Cutting Speed: 121.9 m/min




                                 Hone edge
                                 (Radius = 121.9 µm)
                                 Chamfer edge
                                 115 µm x 17°,
                                 25.4 µm edge radius



                                            [Thiele, 1999]
                                                                                                        7
                     High Performance Machining        Copyright © ERC/NSM 2006. All rights reserved.
                                                                                        ERC
   Introduction - Machining Process as a System
                                                                                        NSM

                                             2

             1                                                  6


                              4
                                         3
                                             3


                                     5
                                                     7
1. Workpiece material                    5. Equipment (rigidity, accuracy,
2. Tooling (geometry, material)          clamping)

3. Interface (friction, heat transfer)   6. Part (shape, usage, …)
4. Deformation zone                      7. Environment
                                                                                                          8
                        High Performance Machining       Copyright © ERC/NSM 2006. All rights reserved.
              Introduction – Finite Element Modeling of                                            ERC
                              Machining                                                            NSM
                                             System inputs
                                             Nature of the Code
Controlable inputs                           Implicit/Explicit
                                             Mesh Generation, ...               Outputs
Material Properties                                                             Simulation Results
Flow stress curve: σ = f(T,ε,dε/dt,...)                                         Cutting forces
Density: ρ = f(T)                                                               Temperatures
Young`s Modulus: E = f(T)                                                       Chip geometry
Poisson‘s ratio: ν = f(T)                                                       Residual stress
Therm. conductivity.: Κ = f(T)                                                  White layer
Spec. heat capacity: cp = f(T)                                                  Tool Wear
Therm. expansion: δ = f(T)                                                      Distribution of
Contact Tribology                                                               • Stress
Friction model: m or µ = f(T,σn,v)                                              • Strain
Interface heat transfer: hint = f(T)                                            • Strain rate
                                            Uncontrollable inputs               • Velocity
Boundary Conditions
Boun. temperatures: T∞= f(model size)       Numerical Influence
Forced convection: henv = f(T)              Number of remeshing steps
Coolant effect on T∞ & henv , ...           Data interpolation algorithm
                                            Numerical damping, ...
                                                                                                                     9
                                   High Performance Machining       Copyright © ERC/NSM 2006. All rights reserved.
                                                                                 ERC
                 Research Objectives
                                                                                 NSM
Develop a hard turning modeling manual and training examples for
using of DEFORM-2D machining template.

Establish a database that includes a verified input data (flow stress
data, elastic and thermal properties, friction conditions) for precise
FE modeling of Hard Turning of AISI 52100 using CBN tools.

Study and determine the influence of tool edge preparation (edge
hone radius, chamfer angle) and process parameters (feed rate,
cutting speed) upon cutting forces, chip morphology, tool stresses,
and tool temperature.




                                                                                                   10
                     High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
                                                                                   ERC
                   Research Approach
                                                                                   NSM

Phase I:     Development of a manual for modeling of machining
             and training examples in using DEFORM-2D machining
             template.

Phase II:    Develop Robust Input Data for Hard Turning Modeling
             of AISI 52100

Phase III:   Determine Effect of Tool Edge Geometry and Cutting
             Conditions upon Orthogonal Hard Turning Variable



     This research is funded by and conducted in cooperation with
     Diamond Innovations, Inc. (Results of NSF projects supported this
     study).
                                                                                                     11
                       High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
     Phase II: Develop Robust Input Data for Hard                                   ERC
                  Turning Modeling                                                  NSM

• Preparation and comparison of material data (available in literature)
  for hardened AISI 52100 steel and CBN tool.

• Estimation of friction conditions at tool-chip contact (sensitivity
  analysis).

• Development of a methodology to combine flow stress models for
  AISI 52100 obtained from orthogonal and compression tests
  (literature data).

• Development of a flow stress model for AISI 52100 using orthogonal
  machining test (disc machining tests done at DI).

• Calibration of the developed flow stress data using orthogonal cutting
  experiments of discs at different feed rates and cutting speeds.
                                                                                                      12
                        High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
                 Phase II: Develop Robust Input Data for Hard                                              ERC
                              Turning Modeling                                                             NSM
                    Preparation and Comparison of Modeling Input Data
                                             Data Analysis
                                                              .
                                   - Variables considered (ε, ε , T,…)
             Elastic & Thermal
CBN




                                   -   Experimental test used
                 properties        -   Applicable ranges of the variables
                                   -   Stress-Strain curves                                        “Best” Flow
                                   -   Stress-Temperature curves                                  Stress (from
                Friction
Tool-Chip
interface




                                                                                                    machining
                                                                                                       test)
                  Heat
                                            Run FE simulation                                            &
                Transfer
                                   using flow stress models (machining                              Ranges of
                 Coeff.                            test)                                          strain, strain
                                                                                                       rate,
             Elastic & Thermal                                                                   temperature at
AISI 52100




                 properties                Results Comparison
                                                                                                   the primary
                                   Compare FE simulations and with                                cutting zone.
                                   experimental data, considering:
             Flow Stress Data      - Cutting forces
                                   - Thrust forces
                                   - Tool-chip contact length
                                   - Chip thickness
                                                                                                                             13
                                 High Performance Machining                 Copyright © ERC/NSM 2006. All rights reserved.
Phase I: Develop Robust Input Data for Hard                                    ERC
             Turning Modeling                                                  NSM
      Flow Stress Data of AISI 52100 (62 HRC)




                       R, H – Machining Tests
                       P, C, U – Compression Tests (extrapolated
                       to high strain and strain rate)




                                                                                                 14
             High Performance Machining         Copyright © ERC/NSM 2006. All rights reserved.
            Phase II: Develop Robust Input Data for Hard                                              ERC
                         Turning Modeling                                                             NSM
      Orthogonal cutting Experiments of AISI 52100 using CBN tools
• Orthogonal cutting experimental data from Diamond Innovations Inc.
  were not available at that time.
• Orthogonal cutting machining data (from literature):
                                                                               Tool-chip               Chip
                   Rake     Hone    Cutting           Cutting    Thrust         contact
                                              Feed                                                  thickness
                   angle   radius    Speed             Force     Force          length
                                              (mm)
                   (deg)    (mm)    (m/min)           (N/mm)    (N/mm)           (mm)                 (mm)


 [Balaji, 2004]     0      0.010     120      0.05     168       169               0.08                  ---


[Ramesh, 2002]      0      0.025    121.92    0.152    389       272                ---                  ---

                                                                                                    hmin= 29
[Jivishov, 2005]    -6     0.008     100      0.06     209       123                ---
                                                                                                    hmax= 69



                                                                                                                        15
                                    High Performance Machining         Copyright © ERC/NSM 2006. All rights reserved.
Phase II: Develop Robust Input Data for Hard                                    ERC
             Turning Modeling                                                   NSM
 Comparison of Predicted and Measured Cutting and
             Thrust Forces (literature)
  Cutting Force                                Thrust Force




Forces predicted using Ramesh and Huang models are closer to
the measured forces.                                                                              16
                  High Performance Machining     Copyright © ERC/NSM 2006. All rights reserved.
Phase II: Develop Robust Input Data for Hard                                ERC
             Turning Modeling                                               NSM
       Comparison of Predicted and Measured
            Tool-Chip Contact Length




Chip-tool contact length predicted when using Ramesh and Huang
models are much larger than the measured value.                                               17
                High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
         Phase II: Develop Robust Input Data for Hard                                   ERC
                      Turning Modeling                                                  NSM
       Predicted Chip Formation for Different Flow Stress Data
Caccialupi Model   Poulachon Model    Umbrello Model


                                                                            Hot
                                                                        Compression
                                                                           Tests


 Huang Model                Ramesh Model



                                                                              Machining
                                                                                Tests


                                                         Note: Balaji’s cutting
                                                         conditions are used in
                                                         the simulations.                                 18
                            High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
          Phase II: Develop Robust Input Data for Hard                                         ERC
                       Turning Modeling                                                        NSM
          Coupling of Huang’s and Umbrello’s Flow Stress Models
• Flow stress models obtained using machining test (such as Huang’s model) are not valid
  for low ranges of strains and temperatures.
• Huang’s model is not sensitive to the temperature compared to other models (i.e., flow
  stress almost constant with the temperature change). In addition, the temperature term in
  Huang’s model (Johnson & Cook’s equation) is not fully capable of representing the non-
  linear temperature effect on flow stress.
  Umbrello’s temperature term
                                           (
                                     EXP a ⋅T 5 + b ⋅T 4 + c ⋅T 3 + d ⋅T 2 + e ⋅T + f 
                                                                                                         )
                                         T − Tr  
                                                    m

  Huang’s temperature term          1 −           
                                         Tm − Tr  
                                                     

• Chips predicted using Huang’s model are much
  thicker than experimentally observed (~2⋅feed).

                                                                                                                 19
                                High Performance Machining      Copyright © ERC/NSM 2006. All rights reserved.
    Phase II: Develop Robust Input Data for Hard                                     ERC
                 Turning Modeling                                                    NSM
     Method to Combine Flow Stress Data from Machining (Huang’s
          Model) and Compression (Umbrello’s Model) Tests

                                       Flow Stress Models Application Ranges



                          Cutting
                          TOOL
                          (fixed)
            Chip Flow
Primary Shear
    zone



       Workpiece
       (moving)

 Hunag’s model (machining) appropriate for Primary Shear Zone, Umbrello’s
 model (compression) appropriate for workpiece and chip.
                                                                                                       20
                        High Performance Machining    Copyright © ERC/NSM 2006. All rights reserved.
        Phase II: Develop Robust Input Data for Hard                                     ERC
                     Turning Modeling                                                    NSM
     Validation of Chip Formation Obtained using Umbrello-Huang’s
               Flow Stress Model for AISI 52100 (~62 HRC)

Jivishov’s cutting experiment conditions:         Experiment                        Prediction




                                                                 [Jivishov, 2005]
                                                                                                         21
                           High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
           Phase II: Develop Robust Input Data for Hard                                                          ERC
                        Turning Modeling                                                                         NSM
     Effective Strain and Cutting Force (Negative Tool)
                                                                                             Workpiece Material:
                                                                                             AISI 52100 (62 HRC)




                                                               Effective Strain
                                                                                             Tool Material:
                                                                                             Low-CBN

                                                                                             Cutting Speed:
                                                                                             100 m/min


                                                                                             Edge Radius:
                                                                                             0.008 mm

                     Experiment                                                              Rake Angle:
                                                                                             -6 deg

                                                                                             Depth of Cut:
                                                                                             0.06 mm

                                                                                             Fracture criterion:
                                                                                             None
22                                                                                                                                 22
                                  High Performance Machining                      Copyright © ERC/NSM 2006. All rights reserved.
      Phase III: Determine the Effect of Tool Edge                                  ERC
          Geometry and Cutting Conditions                                           NSM
Phase III involved the following Tasks:

• Planning the orthogonal (2D) experiments of AISI 52100 using CBN
  tool (at DI).

• Analysis of experimental data (cutting forces, chip morphology, tool-
  chip contact length (wear marks), hone radius before and after
  cutting).

• Prediction of the effect of tool edge geometry (chamfer angle, hone
  radius) and cutting conditions (feed rate, cutting speed) upon cutting
  forces, chip morphology, chip-tool contact length, tool temperature,
  and tool stresses.

• Comparison and correlation of predictions and experiments.

                                                                                                      23
                        High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
     Phase III: Determine Effect of Tool Edge                                    ERC
       Geometry and Cutting Conditions                                           NSM
             Orthogonal Cutting Experiments




Experiments are conducted at DI (Dr. Raja
Kountanya and Dr. Biju Varghese).                                                                  24
                     High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
          Phase III: Determine the Effect of Tool Edge                                             ERC
              Geometry and Cutting Conditions                                                      NSM
          Orthogonal Cutting Experiments (by DI) and Simulations
                                                      α
Common process parameters:
Work Material        AISI- E52100 (60 HRC)
                     Low-CBN (TiN-binder, No coating)
Insert               rake angle (α) of 5 ° and clearance
                     angle (δ) of 6°                                      Chamfer Edge

Width of Cut         3.16 mm (0.125 in)
                     0.2 mm (0.008 in) constant on all                   r
Chamfer Width (w)                                           w
                     tools.                                                                       δ
Variable process parameters:
                                                                    γ

Chamfer Angle (γ)    15, 20, and 30 deg
                                                                                     Cutting
                     0.0005, 0.001, 0.0015 inch (12.7,
Hone Radius (r)                                                                       Tool
                     25.4, and 38.1 µm)
                     200, 300, and 600 fpm (60.96, 91.44,
Cutting Speed (Vc)
                     and 182.88 m/min)
                                                                f
                     0.003 and 0.006 in/rev (0.0762,                     Workpiece
                                                                                                   Vc
Feed Rate (f)
                     0.1524 mm/rev)

                                                                                                                     25
                                 High Performance Machining         Copyright © ERC/NSM 2006. All rights reserved.
        Phase III: Determine the Effect of Tool Edge                                      ERC
            Geometry and Cutting Conditions                                               NSM
                Comparison of Experiments and Predictions

Comparison Parameters:
• Cutting and thrust Force
• Chip morphology
  (Segmentation Frequency,                          tmin
  shear angle, thickness)                                       Cutting Tool
• Tool-Chip contact length
  (wear marks)
• Tool stresses (Simulation)
• Tool temperature (Simulation)
Tool-Chip Contact
Fraction = a / b




                                                                                                            26
                           High Performance Machining      Copyright © ERC/NSM 2006. All rights reserved.
                Phase III: Determine Effect of Tool Edge                                                   ERC
                  Geometry and Cutting Conditions                                                          NSM
               Predicted and Measured Effect of Edge Hone Radius

             Maximum difference: 19%                              Maximum difference: 12%




              Maximum difference: 13%




                                                                     Maximum difference: 2%




Experiments no. 1, 8 and 9: cutting speed = 300 ft/min (91.44 m/min), feed = 0.003 in. (0.0762 mm), rake
angle = 5°(tool holder), clearance angle = 6°, chamfer angle = (-) 20° / Friction: Zorev Model.                              27
                                       High Performance Machining           Copyright © ERC/NSM 2006. All rights reserved.
                  Phase III: Determine Effect of Tool Edge                                                    ERC
                    Geometry and Cutting Conditions                                                           NSM
             Predicted Effect of Edge Hone Radius upon Tool Stresses




Experiments no. 8, 9, and 1(from left): cutting speed = 300 ft/min (91.44 m/min), feed = 0.003 in. (0.0762 mm),
rake angle = 5°(tool holder), clearance angle = 6°, chamfer angle = (-) 20° / Friction: Zorev Model.
                                                                                                                                28
                                       High Performance Machining              Copyright © ERC/NSM 2006. All rights reserved.
                 Phase III: Determine Effect of Tool Edge                                                    ERC
                   Geometry and Cutting Conditions                                                           NSM
          Predicted Effect of Edge Hone Radius upon Tool Temperature




Experiments no. 8, 9, and 1(from left): cutting speed = 300 ft/min (91.44 m/min), feed = 0.003 in. (0.0762 mm),
rake angle = 5°(tool holder), clearance angle = 6°, chamfer angle = (-) 20° / Friction: Zorev Model.
                                                                                                                               29
                                      High Performance Machining              Copyright © ERC/NSM 2006. All rights reserved.
                                                 Phase III: Determine Effect of Tool Edge                                                  ERC
                                                   Geometry and Cutting Conditions                                                         NSM
                                                  Predicted and Measured Effect of Chamfer Angle
                                              Maximum difference: 19%                           Maximum difference: 9%
      Tool-Chip Contact Fraction




                                   0.8
                                              Maximum difference: 17%                           Maximum difference: 7%
                                   0.6

                                   0.4

                                   0.2                          Predictions
                                                                Experiments
                                   0.0
                                         10      15       20      25        30   35
                                                      Chamfer Angle [deg]

Experiments no. 1, 6 and 7: cutting speed = 300 ft/min (91.44 m/min), feed = 0.003 in. (0.0762 mm), hone
edge radius = 15∼20 µm, rake angle = 5°(tool holder), clearance angle = 6° / Friction: Zorev Model.                                                          30
                                                                            High Performance Machining      Copyright © ERC/NSM 2006. All rights reserved.
                  Phase III: Determine Effect of Tool Edge                                                    ERC
                    Geometry and Cutting Conditions                                                           NSM
               Predicted Effect of Chamfer Angle upon Tool Stresses




Experiments no. 6, 1 and 7 (from left): cutting speed = 300 ft/min (91.44 m/min), feed = 0.003 in. (0.0762 mm),
hone edge radius = 15∼20 µm, rake angle = 5°(tool holder), clearance angle = 6° / Friction: Zorev Model.
                                                                                                                                31
                                       High Performance Machining              Copyright © ERC/NSM 2006. All rights reserved.
                  Phase III: Determine Effect of Tool Edge                                                    ERC
                    Geometry and Cutting Conditions                                                           NSM
             Predicted Effect of Chamfer Angle upon Tool Temperature




Experiments no. 6, 1 and 7 (from left): cutting speed = 300 ft/min (91.44 m/min), feed = 0.003 in. (0.0762 mm),
hone edge radius = 15∼20 µm, rake angle = 5°(tool holder), clearance angle = 6° / Friction: Zorev Model.
                                                                                                                                32
                                       High Performance Machining              Copyright © ERC/NSM 2006. All rights reserved.
                 Phase III: Determine Effect of Tool Edge                                                     ERC
                   Geometry and Cutting Conditions                                                            NSM
                Predicted Effect of Cutting Speed upon Tool Stresses


 With increasing cutting
 speed from 91.44 m/min
 to 182.88 m/min, the
 maximum tool stress
 decreases as a result of
 large increase in tool
 temperature (next slide)
 coupled    with   slight
 decrease    in   cutting
 forces.




Experiments no. 4, 1, and 5 (from left): feed = 0.003 in. (0.0762 mm), rake angle = 5°(tool holder), clearance
angle = 6°, chamfer angle = (-) 20°, hone edge radius = 15∼20 µm / Friction: Zorev Model.
                                                                                                                                33
                                       High Performance Machining              Copyright © ERC/NSM 2006. All rights reserved.
                  Phase III: Determine Effect of Tool Edge                                                    ERC
                    Geometry and Cutting Conditions                                                           NSM
             Predicted Effect of Cutting Speed upon Tool Temperature




Experiments no. 4, 1, and 5 (from left): feed = 0.003 in. (0.0762 mm), rake angle = 5°(tool holder), clearance
angle = 6°, chamfer angle = (-) 20°, hone edge radius = 15∼20 µm / Friction: Zorev Model.
                                                                                                                                34
                                       High Performance Machining              Copyright © ERC/NSM 2006. All rights reserved.
                 Phase III: Determine Effect of Tool Edge                                                    ERC
                   Geometry and Cutting Conditions                                                           NSM
            Predicted Effect of Chip Segmentation upon Tool Stresses




Experiments no. 1: cutting speed = 300 ft/min (91.44 m/min), feed = 0.003 in. (0.0762 mm), rake angle = 5°
(tool holder), clearance angle = 6°, chamfer angle = (-) 20°, hone edge radius = 15∼20 µm / Friction: Zorev
Model.                                                                                                                         35
                                      High Performance Machining              Copyright © ERC/NSM 2006. All rights reserved.
                                                                                       ERC
             Summary and Discussion (1 of 2)
                                                                                       NSM
• Collection and comparison of
    – Elastic and Thermal properties and Flow stress models for AISI 52100
      (HRC 62) suitable for machining
    – Materials properties on High-CBN and Low-CBN tools
    – Tool- Chip interface conditions
• Simulations were run using the available flow stress models for AISI 52100
  and comparing the predictions with the experimental data from the
  literature.
• Developed flow stress model based on the coupling of two models
  (machining and compression) enhanced predictions of cutting forces and
  tool-chip contact length.
• Effects of chamfer angle and edge hone radius upon cutting and thrust
  forces, tool-chip contact length, and shear angle are predicted with
  maximum error of 19 %.
• Influences of chamfer angel and edge hone radius upon tool stresses and
  temperature are non-linear.

                                                                                                         36
                           High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
                                                                                      ERC
            Summary and Discussion (2 of 2)
                                                                                      NSM
• Effect of cutting speed and feed rate upon cutting and thrust forces is
  predicted with maximum error of 19 % for speeds within the calibration
  range and up to 41% for cutting speeds and feed rates out of the range.
• Segmented chip formation is predicted, however, the predicted chips have
  average thickness less by ~50% compared to the measured chips.
• Tool von Mises stresses are found to fluctuate by ~16 % of the average
  stress due to chip segmentation.




                                                                                                        37
                          High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
                                                                                                ERC
                               Future Outlook
                                                                                                NSM
• Follow up work:
    – Develop a flow stress model for AISI 52100 using orthogonal machining test (disc
      machining tests done at DI) for better representation of the used AISI 52100.
    – Couple the developed model with a flow stress data from compression test.
    – Calibrate and validate the coupled flow stress data using the orthogonal cutting
      experiments of discs at different feed rates and cutting speeds (conducted at DI).
• Machining Workshop (held on May 2006 at Diamond Innovations, Inc):
    – Follow up with many of the attendees’ comments such as FE modeling reliability, low
      predictability of thrust force compared to experiment, flow stress determination, chip
      segmentation, 3D chip flow, chip breakage, prediction of residual stresses, tool wear.
    – Explore the possibility to establish a consortium for the application of finite element
      modeling of machining in practice.




                                                                                                                  38
                                High Performance Machining       Copyright © ERC/NSM 2006. All rights reserved.
                                                                         ERC
                                                                         NSM




     THANK YOU FOR YOUR ATTENTION

           ANY QUESTIONS?




39                                                                                         39
             High Performance Machining   Copyright © ERC/NSM 2006. All rights reserved.
                                                                                                    ERC
                              Zorev Friction Model
                                                                                                    NSM




     Sticking region: height ≈ 2 x feed. apply shear model, m = 1.
     Sliding region: Coulomb’s friction law, µ = 0.35, because the shear stress decreases on
     the rake face.
                                                                                 [Zorev, 1963]
40                                                                                                                    40
                                   High Performance Machining        Copyright © ERC/NSM 2006. All rights reserved.

								
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