Study of the stress-strain and temperature fields in cutting tools using laser interferometry

OBRABOTKAMETALLOV MATERIAL SCIENCE Том 23 № 3 2021 EQUIPMEN . INSTRUM TS Vol. No. 4 2021  = 0.32 and with the maximum value of the stresses sum Θ = 1600 MPa in the cutting wedge), the com- ponent of deformations caused by thermal stresses will not exceed 14 % of the total tool deformation in the zone with maximum temperature gradient. Therefore, the temperatures at the grid nodes can be determined with suf fi cient accuracy in engineering calculations by using the formula obtained from equation (22) as: 0 è . t t m T T t   = + (23) The proposed methods were implemented in programs created using MATLAB to calculate the stress components and temperatures. Results and Discussion To study the ef fi ciency of the methods, an experiment was performed in which steel grade X13Cr11Ni- 2W2MoV ( EI961 ) was turned using a tool made of cemented tungsten carbide grade WC-8Co ( VK8 ), with a clearance angle  = 10º, rake angle  = –5º, cutting speed V = 0.1 m/s, and feed S = 0.15  10 − 3 m/rev. In- terference patterns obtained by video recording with a frame rate of 16  10 3 fps under the cutting conditions mentioned above, are shown in Fig. 5. Fig. 5. Interference fringe patterns (camera frame rate 16·10 3 fps): a – before the cutting process; б – during the cutting process (maximum load); в – immediately after the interruption of the process; г – one second after the interruption of the process а b c d Figure 6 shows diagrams of the fringe order m distributions along the rake and clearance faces of the tool (with respect to distance R from the cutting edge). Figure 7 shows the fi elds of stress components σ x , σ y , and  xy and the temperature fi eld obtained using the developed methods. The analysis of the stress component σ x distributions shows that the main stresses are compression stresses and their maximum values are observed on the rake face near the cutting edge. The change in component σ y along the rake face is extreme, with a minimum observed in the tool-chip contact zone. As we move closer to the cutting edge, the stress component σ y increases and changes sign. The change in the tangential component τ xy on the rake face is also extreme. As we move closer to the cutting edge, the τ xy component fi rst decreases to a minimum negative value, and then increases and changes sign. In the contact zone, a narrow zone of negative τ xy values is observed on the clearance face, and outside the contact zone, the component τ x y = 0. The temperature fi eld was quite uniform. The temperature values were relatively low because of the high thermal conductivity of the tool material and low cutting speed. The maximum temperature was observed at the cutting edge. Moving away from the edge, the temperature decreased, while a larger gradient was observed along the rake face. The nature of the temperatures and stress distributions obtained by proving the ef fi ciency of the developed methods coincide with the results obtained by alternative methods in other studies [1, 14].