On the transition of failure mechanisms during machining process with varied speeds: A molecular dynamics study

Zhang，J. Q.; He，B. B.; Zhang，B.

2023-11-24

10.1016/j.jmapro.2023.09.064

Journal of Manufacturing Processes   影响因子和分区

1526-6125

2212-4616

Conventional machining theory states that the machining of a ductile material may create continuous, serrated, and/or fragmented chips with increasing machining speeds. In this study, transitions of failure mode under varied machining speeds in single-crystalline silicon were analyzed based on molecular dynamics (MD) simulations of the ultra-high-speed machining of single-crystalline silicon. The MD simulations employ the periodic boundary conditions along the third direction which can mimic the material failure in cutting plane. The uncut depth reaches 39 nm, which is sufficiently large to accommodate complex atomic evolutions. The simulation results indicate that jetted chips occurred in front of the cutter, when the machining speed is increased to approximately 2.7 × 10 m/s, which is attributed to the shock pressure induced by the chip inertia. Essentially, the Rankine-Hugoniot jump conditions were introduced to explain the influence of the shock pressure. Both the calculations based on Rankine-Hugoniot jump conditions and the MD results imply that the shock wave speed is equal to the machining speed at the steady machining state. In addition, the transition from fragmented-chip to jetted-chip morphology exhibits a stage wherein the two primary adiabatic shear bands are simultaneously activated. The present work sheds light on the underlying mechanism of chip formation at an ultra-high-machining speed beyond 1000 m/s.

Adiabatic shear banding Molecular dynamic simulation Shock wave Ultra-high-speed machining

SCI ; EI

英语

第一 ; 通讯

Peacock Program of Shenzhen[KQTD20190929172505711] ; Shenzhen Science and Technology Innovation Commission of China[JSGG20210420091802007] ; Guangdong Province[2021B1515120009]

Engineering

Engineering, Manufacturing

WOS:001105421100001

ELSEVIER SCI LTD

20234214904853

Ductile fracture ; Shear bands ; Shear flow ; Shock waves

Fluid Flow, General:631.1 ; Physical Chemistry:801.4 ; Classical Physics; Quantum Theory; Relativity:931

2-s2.0-85173907540

Scopus

Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Zhang，J. Q.,He，B. B.,Zhang，B.. On the transition of failure mechanisms during machining process with varied speeds: A molecular dynamics study[J]. Journal of Manufacturing Processes,2023,106:537-551.

Zhang，J. Q.,He，B. B.,&Zhang，B..(2023).On the transition of failure mechanisms during machining process with varied speeds: A molecular dynamics study.Journal of Manufacturing Processes,106,537-551.

Zhang，J. Q.,et al."On the transition of failure mechanisms during machining process with varied speeds: A molecular dynamics study".Journal of Manufacturing Processes 106(2023):537-551.