Grain and geometry size effects on plastic deformation in roll-to-plate micro/meso-imprinting process

et al. 2018

Micromachines

The fabrication of the micro-channel array through micro-embossing on an ultrafine-grained (UFG) LZ91 Mg-Li alloy was investigated in this paper. Micro-embossing tests indicated that the depth of the channels increase with increasing temperatures. Micro-array channels with widths ranging from 50 μm to 200 μm were performed with an applied force of 2 kN at 423 K, following by a dwell time of 60 s on the UFG LZ91 Mg-Li alloy. The surface topography indicates that embossed micro-channels for UFG LZ91 Mg-Li with all widths are clearly printed well with good geometrical transferability and no obvious defects. The comparison filling behavior of UFG and the CG LZ91 Mg-Li alloy reveals that grain sizes mainly affect the filling quality of micro-embossing. The results indicate a potential application of the UFG Mg-Li alloy in the mass fabrication of micro-electro-mechanical system (MEMS) components.

Section: Introductionmentioning

confidence: 99%

The Fabrication of Micro-Array Channels with the Ultrafine-Grained LZ91 Mg-Li Alloy by Micro-Embossing

et al. 2018

Micromachines

“…The experiments in this paper showed the same type of defects for the same reason in Gao [20,21] and Klocke [22][23][24]. It was di cult to coordinate the two simultaneous behaviors of plate extension and micro-groove formation.…”

Section: Defect Analysismentioning

confidence: 67%

Process Analysis and Roller Optimization of Micro-Groove Multi-Pass Rolling

Gao

Zhu

et al. 2021

Preprint

Micro-grooves with special structure can reduce the surface friction resistance. Rolling method can be used to form micro-grooves on metal surface efficiently. However, the micro grooves formed by this plastic forming method still had some defects, which had a serious negative impact on the drag reduction and mechanical properties of the micro grooves. Therefore, it is of great significance to optimize the multi pass rolling process to avoid the micro-groove defects. In this paper, a series of analysis on the microstructure, strain and material displacement of micro-grooves were carried out to explain the causes of micro groove defects. It was found that the overall extension of the plate has an adverse effect on the formation of micro-grooves and the hole types of the roller were optimized accordingly. The results of simulation and experiment showed that the optimized roller could produce the designed micro-groove, which perfectly avoided the generation of micro defects.

“…Gao et al [21,22] designed the Roll to Plate (R2P) method to manufacture rectangular micro-grooves. That is, firstly, the workpiece was placed on a mold plate with microgrooves, and then the micro-groove structures were pressed on the workpiece by the pressure from two flat rollers.…”

Section: Introductionmentioning

confidence: 99%

Process analysis and hole type optimization of micro-groove multi-pass rolling

Int J Adv Manuf Technol

Gao

Zhu

et al. 2021

The micro-grooves with special structure and size have the special function of reducing surface flow resistance. Placing the micro-grooves over a larger area on the aircraft surface can achieve effective drag reduction, that is, a decrease in the resistance experienced during operation. Rolling method can be used to form micro-grooves on metal surface efficiently. However, the micro-grooves formed by this plastic forming method may have some defects, which in turn could cause serious negative impact on the drag reduction and mechanical properties of the micro-grooves. Therefore, optimization of the multi-pass rolling process to avoid the micro-groove defects is of great significance. This paper includes a series of analysis on the microstructure, strain, and material displacement of micro-grooves, which were carried out to explain the causes of micro-groove defects. Micro-grooves were formed on the surface of the sheet, and the plate also underwent both thickness reduction and extension in the Y-direction, under the pressure exerted by the roller. It was found that the extension of the plate had an adverse effect on the formation of micro-grooves; thus, the hole types of the roller were optimized accordingly. The simulation and experimental results showed that the optimized roller could produce the desired micro-grooves, which perfectly eliminated the generation of micro defects.