The Influence of Crystal Lattice Type on the Process of Chip Formation During Cutting

The mechanism of jointed (segmented) chip formation at high cutting speeds is considered. It is shown that this phenomenon is associated with an increase in the yield strength of the metal and a reduction in its ductility with an increase in the cutting speed, and consequently in the rate of deformation. The increase in the rate of deformation with the increasing cutting speed creates a less energy-intensive brittle mechanism of chip element fracture. This, in turn, leads to a decrease in the degree of deformation of the cut layer, cutting forces and chip shrinkage. The effect of the type of crystal lattice of the machined material on the appearance of the chips is manifested through the stacking fault energy that affects the formation of the dislocation structure in the chip formation zone, which determines the output parameters of the cutting process, i.e. resistance to plastic deformation, cutting forces, degree of deformation and shrinkage of the cut layer.

References

[1] Bobrov V.F., Sidel’nikov A.I. Osobennosti obrazovaniia sustavchatoi i elementnoi struzhek pri vysokoi skorosti rezaniia [The formation of jointed and elemental chips at high cutting speeds]. Vestnik mashinostroeniia [Russian Engineering Research]. 1976, no. 7, pp. 61–66.

[2] Poduraev V.N. Obrabotka rezaniem zharoprochnykh i nerzhaveiushchikh materialov [Machining heat-resistant and stainless material]. Moscow, Vysshaia shkola publ., 1965. 518 p.

[3] Ivanov O.I. K voprosu modelirovaniia protsessa struzhkoobrazovaniia pri rezanii metallov [On the simulation of chip formation process by metal-cutting]. Vektor nauki TGU [Vector of sciences. Togliatti State University]. 2014, no. 3(29), pp. 57–61.

[4] Efimovich I.A. Tsiklicheskii kharakter napriazhenno-deformirovannogo sostoianiia rezhushchei chasti instrumenta v protsesse rezaniia [The cyclical nature of stress-strain state of the cutting tool during the cutting process]. Vestnik mashinostroeniia [Russian Engineering Research]. 2003, no. 7, pp. 48–52.

[5] Vorontsov A.L., Sultan-Zade N.M., Albagachiev A.Yu. Development of a new theory of cutting: 4. General principles of a new theory of cutting. Russian Engineering Research, 2008, vol. 28, no. 4, pp. 346–351.

[6] Veits V.L., Maksarov V.V. Model’ formirovaniia lokal’nykh polos sdviga v zone plasticheskoi deformatsii srezaemogo sloia [The model of formation of local shear bands in the plastic-deformation zone shear layer]. Mashinostroenie i avtomatizatsiia proizvodstva: Mezhvuz. Sb. [Mechanical engineering and automation of production. Interuniversity collection]. Sankt-Petersburg, SZPI publ., 1999, is. 14, pp. 32–34.

[7] Komanduri R., Von Turkovich B.F. New observations on the mechanism of chip formation when ma chining titanium alloys. Wear, 1981, vol. 69, no. 2, pp. 179–188.

[8] Zorev N.N. Voprosy mekhaniki protsessa rezaniia [Problems of mechanics of cutting process]. Moscow, Mashgiz publ., 1956. 365 p.

[9] Kabaldin Iu.G., Kuz’mishina A.M. Atomnyi podkhod k protsessam deformatsii i razrusheniia srezaemogo sloia pri rezanii [Approach to nuclear and destruction deformation process of cutting layer cutting]. Trudy NGTU im. R.E. Alekseeva [Works of NSTU named after R.E. Alekseev]. 2014, no. 2(104), pp. 78–88.

[10] Gol’dshtein M.I., Litvina V.S., Bronfin B.M. Metallofizika vysokoprochnykh splavov [Metallophysics of high-strength alloys]. Moscow, Metallurgiia publ., 1988. 312 p.

[11] Veits V.L., Maksarov V.V., Kozlova E.B. Matematicheskoe modelirovanie protsessa struzhkoobrazovaniia pri lezviinoi obrabotke [Mathematical modeling of process of chip formation with processing blade]. Mashinostroenie i avtomatizatsiia proizvodstva: Mezhvuz. Sb. [Mechanical engineering and automation of production. Interuniversity collection]. Sankt-Petersburg, SZPI publ., 1999, is. 14, pp. 139–145.

[12] Rozenberg A.M., Rozenberg Iu.A. Mekhanika plasticheskogo deformirovaniia v protsessakh rezaniia i deformiruiushchego protiagivaniia [Mechanics of plastic deformation in the process of cutting and deforming broaching]. Kiev, Naukova dumka publ., 1990. 320 p.

[13] Obrabotka rezaniem zharoprochnykh, vysokoprochnykh i titanovykh splavov [Machining of high-temperature, high-strength titanium alloys]. Ed. Reznikov N.I. Moscow, Mashinostroenie publ., 1972. 200 p.