State of the art in micro forming

Vollertsen, Frank; Niehoff, H. Schulze; Hu, Zhenbang

doi:10.1016/j.ijmachtools.2006.01.033

Cited by 254 publications

(128 citation statements)

References 9 publications

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“…variations in material and mechanical properties as the processes are miniaturised to micro scale, which have been reported extensively [2][3][4][5][6]. When the microstructure is kept as a constant, only a few grains are involved within the micro scale components through the dimension of interest, and thus there are only a few grains located in the deformation zone.…”

Section: Introductionmentioning

confidence: 99%

Influences of temperature and grain size on the material deformability in microforming process

Jiang

Zhao

et al. 2016

Int J Mater Form

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This paper investigated the influences of temperature and grain size on the deformability of pure copper in micro compression process. Based on the dislocation theory, a constitutive model was proposed taking into account the influences of forming temperature, Hall-Petch relationship and surface layer model. Vacuum heat treatment was employed to obtain various grain sizes of cylindrical workpieces, and then laser heating method was applied to heat workpieces during microforming process. Finite element (FE) simulation was also performed, with simulated values agreed well with the experimental results in terms of metal flow stress. Both the FE simulated and experimental results indicate that forming temperature and grain size have a significant influence on the accuracy of the produced product shape and metal flow behaviour in microforming due to the inhomogeneity within the deformed material. The mechanical behaviour of the material is found to be more sensitive to forming temperature when the workpieces are constituted of fine grains. experimental results indicate that forming temperature and grain size have a significant influence on the accuracy of the produced product shape and metal flow behaviour in microforming due to the inhomogeneity within the deformed material. The mechanical behaviour of the material is found to be more sensitive to forming temperature when the workpieces are constituted of fine grains.

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Section: Introductionmentioning

confidence: 99%

Influences of temperature and grain size on the material deformability in microforming process

Jiang

Zhao

et al. 2016

Int J Mater Form

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“…With the constant improvement of macro manufacturing, people gradually begin to research in the micro field [1][2]. Micro parts made by sheet metal are widely used in the fields of communications, electronics, and micro-electromechanical systems.…”

Section: Introductionmentioning

confidence: 99%

The Investigation on Mask and Plasticine Laser Shock Forming

et al. 2016

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Abstract.A novel technology called mask and plasticine laser shock forming (MAPLSF) was introduced to manufacture micro-features on the surface of pure copper foil with the thickness of 40ȝm. In this process, the laser-generated shock wave and plasticine are used to replace the conventional rigid punch and die. The result showed that the shape of laser beam can be roughly manufactured on the surface of the workpiece and this mold-free laser shock forming process is a fast method to fabricate controlled micro-feature on the metallic foils. In this damage-free forming process, the workpicec can keep good surface, because the plasticine is softer than metal foils.

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“…Engle and Eckstein [1] proposed the surface layer model in which the specimen was divided into two portions: interior part and surface layer, to explain the reduction of flow stress in microforming process. Geiger et al [4] and Vollertsen et al [2,5] published papers with respect to micro-forming and carried out a comprehensive review of state of the art of micro-forming technology. Ma et al [6] researched the size effect on fracture behaviour in deep drawing process.…”

Section: Introductionmentioning

confidence: 99%

Grain size effect of thickness/average grain size on mechanical behaviour, fracture mechanism and constitutive model for phosphor bronze foil

Fang

Jiang

Wang

et al. 2015

Int J Adv Manuf Technol

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X. (2015). Grain size effect of thickness/average grain size on mechanical behaviour, fracture mechanism and constitutive model for phosphor bronze foil. International Journal of Advanced Manufacturing Technology, 79 (9-12), 1905Technology, 79 (9-12), -1914 Grain size effect of thickness/average grain size on mechanical behaviour, fracture mechanism and constitutive model for phosphor bronze foil AbstractSize effects play a significant role in microforming process, and any dimensional change can have a great impact on materials' mechanical properties. In this paper, the size effects on deformation behaviour and fracture of phosphor foil were investigated in the form of grain size effect: the ratio of materials' thickness (T) to average grain size (D) by micro tensile tests. The ratio was designed to be closed to but larger than, less than and equal to 1, respectively. The results show that the amount of plastic deformation decreases with the decrease of the ratio of T/D, which indicates that the grain size plays a significant role and grain deformation modes differ when the ratio changes. It is also found that their fractograph reflects different features in terms of micro-dimples and cleavage planes, further demonstrating that when T/D >1, its materials have a tendency to fracture ductilely, while materials would like to conduct brittle fracture when T/D Grain size effect of thickness/average grain size on mechanical behaviour, fracture mechanism and constitutive model for phosphor bronze foil Abstract: In this paper, the size effects on deformation behaviour and fracture of phosphor foil were investigated in terms of the ratio of materials' thickness (T) to average grain size (D) by micro tensile tests. The results show that the amount of plastic deformation decrease with the decrease of the ratio of T/D, which indicates that the grain size plays a significant role and grain deformation modes differ when the ratio changes. It is also found that their fractograph reflect different features in terms of micro-dimples and cleavage planes, further demonstrating that when T/D>1, its materials have a tendency to fracture ductilely, while materials would like to conduct brittle fracture when T/D<1. So the ratio of T/D which is close to 1 can be regards as the divide of ductile fracture and brittle fracture. For T/D<1, a new constitutive model is proposed based on the classic composite model. The model's results are compared with the experimental ones and the efficiency of the developed models is verified.

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State of the art in micro forming

Cited by 254 publications

References 9 publications

Influences of temperature and grain size on the material deformability in microforming process

Influences of temperature and grain size on the material deformability in microforming process

The Investigation on Mask and Plasticine Laser Shock Forming

Grain size effect of thickness/average grain size on mechanical behaviour, fracture mechanism and constitutive model for phosphor bronze foil

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