International Journal of Machine Tools

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International Journal of Machine Tools

  1. 1. Investigation of the effect of rake angle and approaching angle on main cutting force and tool tip temperature<br />International Journal of Machine Tools & Manufacture<br />Authors: HaciSaglam<br />FarukUnsacar<br />SuleymanYaldiz<br />Date of Publication: May 5, 2005<br />Presenter: Matt Maxfield<br />Date: October 7, 2009<br />
  2. 2. Function of this Paper<br />Compare measured and calculated results of cutting force components and temperature variation on the tool tip of various tool geometries used in machining AISI 1040 Steel<br />
  3. 3. The Importance of Cutting Force & Temperature<br />Due to more demanding manufacturing processes and systems, the requirements for reliable technological information have increased<br />Cutting forces are mainly affected by cutting speed, feedrate, undeformed chip thickness, cutting tool material, tool geometry, depth of cut and tool wear<br />There are many empirical equations for cutting force but experimental measurements are more reliable<br />Predicting temperature distribution is important in determining the maximum cutting speed<br />
  4. 4. References<br />
  5. 5. How does this relate to us?<br />Learning about machining processes<br />Learning about the effects of tool geometry <br />Rake face - tool’s leading edge<br />Rake angle - slant angle of tool’s leading edge (α)<br />Flank - following edge of cutting tool<br />Relief angle – angle of tool’s following edge above part surface <br />
  6. 6. Design and Parameters<br />Tested practically under workshop conditions<br />Each test conducted with sharp uncoated carbide tool insert<br />Constants<br />Depth of cut<br />Cutting speed<br />Variables<br />Approach angle<br />Rake angle <br />Work piece material selected to represent the major group used in industry (AISI 1040 Steel)<br />Full factorial design<br />
  7. 7. Method of Testing <br />Experiments were carried out on a CNC turning machine<br />Main cutting force (Fc), feed force (Ff), and thrust force (Ft) were measured using a three component turning dynamometer<br />A radiation sensor was used for temperature measurement on the tool tip<br />
  8. 8. Method of Testing <br />Test conducted under dry conditions<br />Full factorial design of experiment<br />Experimental results compared with calculated results<br />
  9. 9. Calculating Forces and Temperatures<br />Main cutting force (Fc)<br />Ac = chip cross-sectional area<br />Ks = specific cutting force<br />Average temperature rise<br />Pu = friction power spent on the tool face<br />Pu = FuVc<br />Fu= friction force<br />Fu = Fc sin αr +Ff cosαr<br />Mc = metal removal rate<br />Cs = specific coefficient of heat of workpiece<br />
  10. 10. Experimental Results<br />The effect of approaching angle on main cutting force and tool tip temperature<br />
  11. 11. Experimental Results<br />The effect of rake angle on main cutting force and tool tip temperature<br />
  12. 12. Experimental Results<br /><ul><li>The effect of feedrate on main cutting force and tool tip temperature</li></li></ul><li>Correlations of Experimental vs. Calculated<br />Deviation of calculated cutting force components form measured values<br />Average deviation of main cutting force calculations for 64 experiments was 0.37%<br />
  13. 13. Design Challenges<br />The average deviation of the temperature for 64 experiments was 42%<br />Due to the flowing chips some of the heat was conducted to the workpiece and an acurate tool tip measurement was not able to be made<br />For a reliable measurement a thermocouple should be embedded into the cutting insert<br />
  14. 14. Conclusions<br />Increasing the rake angle over its optimum value has a negative effect on tool’s performance and accelerates tool wear which leads to an increase in cutting force<br />It is difficult to create a fully comprehensive model of all cutting parameters for cutting force<br />Feedrate = cutting force<br />Rake angle = cutting force<br />Optimum rake angle = 12°<br />Optimum machining at γ=0° and χ=75° <br />
  15. 15. Conclusions<br />How does this paper help in industry?<br />Practical in gaining a better understanding of the effects of rake angle and approach angle on cutting force but did have some design flaws in analyzing temperature<br />Is there any technical advancement?<br />It adds to the current knowledge about cutting force variables by testing parameters not studied as frequently<br />What industries are most affected by this research?<br />Machinist who work with steel <br />Most industries<br />

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