Akademik Veri Yönetim Sistemi
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS, PART E: JOURNAL OF PROCESS MECHANICAL ENGINEERING, cilt.0, sa.0, ss.1-14, 2025 (SCI-Expanded, Scopus)
This study addresses the effects of cryogenic
cooling-induced severe plastic deformation (SPD) on microstructure alteration
and dynamic recrystallization in the machining of 316LVM alloy. In particular,
surface integrity properties such as nanocrystallization, phase transformation,
and deformation hardening in the subsurface layer were experimentally
investigated. Machining was carried out under liquid nitrogen cooling with
cutting parameters consisting of a cutting speed of 300 m/min, a depth of cut
of 1.2 mm, and two different feedrates (0.1 and 0.5 mm/rev). An SPD layer with
a thickness of ~27-38 μm and a featureless layer with a thickness of 6 μm were
detected in the subsurface of the sample machined at the high feedrate. Furthermore,
nanostructures with grain features averaging 93 nm in size were observed in the
featureless layer using an atomic force microscope. As a result of X-ray
diffraction analysis, while no deformation-induced martensitic phase
transformation was observed in the nanocrystal surface layer, a 338% peak
broadening was detected. Due to work-hardening, microhardness increased by
115%, reaching 516 HV at a depth of 10 μm in the subsurface. It is thought that
the nanocrystallization occurring in the 316LVM alloy with high stacking fault
energy results from continuous dynamic recrystallization induced by SPD.