Calculation of Contact Stresses during Titanium Alloy Cutting

Abstract:

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 N_ρ, directed perpendicularly to a transient surface, with a large magnitude of specific linear force q_{N r} = 182.6 N/mm, but the tangential force on the cutting edge F_ρ is 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 σ_max ≈ 1009 MPa, irrespective of feed rate. The greatest magnitude of normal contact stresses on the flank surface chamfer near the cutting edge σ_{h 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 σ_h and shear τ_h contact 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 (h_f > 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.

• Periodical: Key Engineering Materials (Volume 769)
• Pages: 364-370
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.769.364
• Online since: April 2018
• Authors: Victor Kozlov*, Jia Yu Zhang, Ying Bin Guo, Sai Kiran Sabavath
• Keywords: Contact Load Distribution, Contact Stresses, Flank Surface Chamfer, Machining Titanium Alloy, Tool Wear

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