Chip-free surface patterning of toxic brittle polycrystalline materials through micro/nanoscale burnishing
Authors: Weihai Huang, Jiwang Yan *
Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
Burnishing of toxic brittle crystalline materials is performed to avoid chip generation.
The formation mechanisms of slip lines and cracks in burnishing process are revealed.
Local lattice distortion dominates the subsurface layer while no phase transformation occurs.
Twin boundary blocks the dislocation propagation and cause grain boundary step formation.
Various types of micro patterns are created on polycrystalline zinc selenide by burnishing
DOI: https://doi.org/10.1016/j.ijmachtools.2020.103688
Multiscale modeling of coupling mechanisms in electrically assisted deformation of ultrathin sheets: An example on a nickel-based superalloy
Authors: Y.Z. Liu, M. Wan, B. Meng *
School of Mechanical Engineering and Automation, Beihang University, Beijing, 100191, PR China
Grain size effect in electrically assisted deformation of ultrathin superalloy sheets was investigated.
Dislocation density model was modified and verified to consider grain size and electroplastic effects.
Joule heating effect and normalized flow stress reduction are non-monotonically related to grain size.
Pulsed current suppresses the grain size effect of polycrystalline, but promotes that for multicrystalline.
DOI:https://doi.org/10.1016/j.ijmachtools.2021.103689
Stability properties of regenerative cutting processes, based on impulse response functions expressed in the impulse dynamic subspace
Authors: Zoltan Dombovari *
MTA-BME Lendület Machine Tool Vibration Research Group, Department of Applied Mechanics, Budapest University of Technology andEconomics, Budapest H-1521, HungaryDynamics and Control Department, Ideko, Elgoibar E20870, Spain
Machining process dynamics is described using measured signals directly.
Process models are directly constructed by using impulse response functions.
Dynamics of machining processes is transformed by using impulse dynamic subspace.
Numerical method on the base of acquired frequency response functions.
Surface property, stability behavior and measure of stability are determined.
Effectivity, convergence tests and experimental validations are performed.
DOI: https://doi.org/10.1016/j.ijmachtools.2021.103691
Towards understanding the machining mechanism of the atomic force microscopy tip-based nanomilling process
Authors: Jiqiang Wang a,b, Yongda Yan a,b, Zihan Li b, Yanquan Geng a,b,*
a The State Key Laboratory of Robotics and Systems, Robotics Institute, Harbin Institute of Technology, Harbin, Heilongjiang, 150080, PR China
b Center for Precision Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, 150001, PR China
A theoretical model of nanomilling process was established to predict the machined depth of the nanochannel.
The undeformed chip thickness, brittle-to-ductile transition and machining mechanism were investigated.
The material removal mechanism in brittle regime was analyzed on the basis of the holistic elastic stress field.
The sample subsurface damage and phase transformation for nanomilling were investigated by TEM and Raman.
The parameters for nanomilling process to fabricate nanochannel without pile-up on silicon were obtained.
DOI: https://doi.org/10.1016/j.ijmachtools.2021.103701