High Precision Micro-Grinding of Advanced Materials
Doctoral thesis, 2021
The results show that the flow stress of the material did not change with the changing of cutting speed and cutting strain rate. Moreover, it was observed that the depth of cut and grinding feed rate had the same (neutral) effect on the resultant grinding forces. Therefore, the efficiency of titanium micro-grinding could be highly influenced by changing the topography of the micro-grinding tool through different dressing parameters. However, using higher chip thicknesses resulted in a more efficient process in terms of cutting/chip-formation. The lowest specific energy, obtained in the single grain tests, was 11.5 J/mm3 for both-types of titanium materials. In contrast, a much higher minimum specific energy in real micro-grinding process with several (bonded) grains was observed – showing a higher amount of ploughing and rubbing/friction in the micro-grinding process. The build-up direction of additively-manufactured titanium, at low chip thickness, affected the process efficiency. In larger chip thicknesses, almost the same specific energy was measured independent of the material manufacturing method. The results of the XRD analysis showed that contrary to the specific grinding energy, the residual stresses of the ground surface changed by varying the cutting speed and feed-rate-to-depth-of-cut ratio, vw/ae. Higher cutting speeds resulted in lower compressive residual stress, and higher feed-rate-to-depth-of-cut ratios resulted in higher compressive stresses. This can be attributed to higher temperatures in the chip-formation process compared to the plastic deformation in micro-grinding at higher cutting speeds and lower vw/ae ratios, which was proved via SEM micrographs. A more efficient micro-grinding process was achieved via the Laser-Assisted Micro-Grinding (LAMG) process of a Si3N4 workpiece, where the values of the specific grinding energy, as well as the tool deflection by the LAMG process, were much lower than the Conventional Micro-Grinding (CMG) process.
Ceramic
Additive manufacturing
Laser-assisted micro-grinding
Modeling
Surface integrity
Titanium
Micro-grinding
Process efficiency
Author
Mohammadali Kadivar
Chalmers, Industrial and Materials Science, Materials and manufacture
The effect of dressing parameters on micro-grinding of titanium alloy
Precision Engineering,;Vol. 51(2018)p. 176-185
Journal article
Modeling of the micro-grinding process considering the grinding tool topography
International Journal of Abrasive Technology,;Vol. 8(2017)p. 157-170
Journal article
Laser-assisted micro-grinding of Si3N4
Precision Engineering,;Vol. 60(2019)p. 394-404
Journal article
Surface integrity in micro-grinding of Ti6Al4V considering the specific micro-grinding energy
Procedia CIRP,;Vol. 87(2020)p. 13-18
Paper in proceeding
Performance of micro-grinding pins with different bonding while micro-grinding Si3N4
International Journal of Abrasive Technology,;Vol. 10(2020)p. 16-31
Journal article
Modeling of micro-grinding forces considering dressing parameters and tool deflection
Precision Engineering,;Vol. 67(2021)p. 269-281
Journal article
The role of specific energy in micro-grinding of titanium alloy
Precision Engineering,;Vol. 72(2021)p. 172-183
Journal article
A fundamental investigation was carried out to explore the aspects of grindability (machinability) for advanced materials produced by distinct manufacturing methods, like additive manufacturing and conventional method, from the perspective of grinding forces, specific energy, and surface integrity. This study aimed to understand the effects of process parameters, i.e., cutting speed, the ratio of feed rate to depth of cut, different lubrication conditions and grinding tool topography and its specification on grindability of titanium and silicon nitride (Si3N4). The specific grinding energy is used as a major indicator of grindability in this study. Moreover, in order to achieve a highly precise and effective micro-grinding process, the surface integrity was analyzed in addition to the specific grinding energy.
The research provides a closer look in the micro-grinding process via experimental investigation and modeling studies to find the interaction mechanisms in micro-grinding of ductile and brittle materials for an accurate and efficient process. The present thesis is planned for both academic and industry parties. Researchers can obtain inspiration from the literature analysis through various scientific disciplines, and the effect of fundamental process parameters like chip thickness in process efficiency. Industrial experts can reflect on the role of process parameters in micro-grinding of advanced materials to produce accurate micro-parts without or with minimum surface and subsurface damages.
Subject Categories
Mechanical Engineering
Production Engineering, Human Work Science and Ergonomics
Areas of Advance
Production
ISBN
978-91-7905-457-1
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4924
Publisher
Chalmers
Online via Zoom
Opponent: Jan C. Aurich, Prof. Dr.-Ing, University of Kaiserslautern, Germany