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Full-Text Articles in Social and Behavioral Sciences
Effect Of Grain Size On Springback And System Energy In Micro V-Bending With Phosphor Bronze Foil, Zhi Fang, Zhengyi Jiang, Xiaogang Wang, Cunlong Zhou, Xianming Zhao, Xiaoming Zhang, Di Wu
Effect Of Grain Size On Springback And System Energy In Micro V-Bending With Phosphor Bronze Foil, Zhi Fang, Zhengyi Jiang, Xiaogang Wang, Cunlong Zhou, Xianming Zhao, Xiaoming Zhang, Di Wu
Faculty of Engineering and Information Sciences - Papers: Part A
In this paper, the effect of grain size on springback in the micro V-bending process of phosphor bronze foil (face-centered cubic structure) is investigated. Grain size effect is expressed by the ratio of material thickness (T) to average grain size (D), and these T/D values are divided into three groups: larger than 1, less than 1, and approximately equal to 1. It has been found that springback angles were the lowest when T/D ≈ 1. Electron backscattering diffraction (EBSD) measurement results show that the twinning boundaries change with the ratios of T/D before and after bending. When T/D > 1, the …
Analysis Of Micro Flexible Rolling With Consideration Of Material Heterogeneity, Feijun Qu, Zhengyi Jiang, Haina Lu
Analysis Of Micro Flexible Rolling With Consideration Of Material Heterogeneity, Feijun Qu, Zhengyi Jiang, Haina Lu
Faculty of Engineering and Information Sciences - Papers: Part A
This paper establishes a finite element model to numerically study the springback in thickness direction during micro flexible rolling process, in which 3D Voronoi tessellation has been applied to describe grain boundary and generation process of grain in the workpiece. To reflect material heterogeneity, nine kinds of mechanical properties defined by nine types of heterogeneity coefficients are selected and assigned to Voronoi polyhedrons as per the statistical distribution of hardness of grains identified by micro hardness testing. Initial workpiece thicknesses of 100, 250 and 500 μm with reduction changing from 20% to 50% are respectively considered in the numerical simulation …
Microstructure And Micro-Texture Evolution During The Dynamic Recrystallisation Of A Ni-30fe-Nb-C Model Alloy, Parvez Mannan, Ahmed A. Saleh, Azdiar A. Gazder, Gilberto Casillas, Elena V. Pereloma
Microstructure And Micro-Texture Evolution During The Dynamic Recrystallisation Of A Ni-30fe-Nb-C Model Alloy, Parvez Mannan, Ahmed A. Saleh, Azdiar A. Gazder, Gilberto Casillas, Elena V. Pereloma
Faculty of Engineering and Information Sciences - Papers: Part A
The evolution of microstructure and micro-texture during discontinuous dynamic recrystallisation of an austenitic Ni-30Fe-Nb-C model alloy subjected to interrupted plane strain compression at strains (ε) of 0.23, 0.35, 0.68, 0.85 and 1.2 was investigated using electron backscattering diffraction and transmission electron microscopy. Throughout the strain range, the majority of dynamic recrystallisation events comprised nucleation in necklace-like arrangements located at and along grain boundaries via bulging. At ε ≥ 0.68, discrete nucleation events were also observed within grain interiors. Grain growth during dynamic recrystallisation is characteristic of strain induced boundary migration. The initial texture comprised Cube-RD ({013}〈100〉), Cube-ND ({001}〈310〉) and Cube …
Effects Of Hydraulic Pressure On Wrinkling And Earing In Micro Hydro Deep Drawing Of Sus304 Circular Cups, Liang Luo, Dongbin Wei, Xiaogang Wang, Cunlong Zhou, Qingxue Huang, Jianzhong Xu, Di Wu, Zhengyi Jiang
Effects Of Hydraulic Pressure On Wrinkling And Earing In Micro Hydro Deep Drawing Of Sus304 Circular Cups, Liang Luo, Dongbin Wei, Xiaogang Wang, Cunlong Zhou, Qingxue Huang, Jianzhong Xu, Di Wu, Zhengyi Jiang
Faculty of Engineering and Information Sciences - Papers: Part A
Influences of hydraulic pressure on forming features in micro hydro deep drawing are different from those in normal drawing due to the small size of specimens. In this study, micro hydro deep drawing of SUS304 sheets was carried out in order to study the impacts of the hydraulic pressure on the quality of the drawn cup. Experimental results indicate that there is a critical hydraulic pressure range from 3 to 6 % of the blank's initial yield stress, where wrinkling and earing development trends change twice. The wrinkling and the earing of the drawn cup also reach their local extremes …
A New Micro Scale Fe Model Of Crystalline Materials In Micro Forming Process, Liang Luo, Haibo Xie, Dongbin Wei, Xiaogang Wang, Cunlong Zhou, Zhengyi Jiang
A New Micro Scale Fe Model Of Crystalline Materials In Micro Forming Process, Liang Luo, Haibo Xie, Dongbin Wei, Xiaogang Wang, Cunlong Zhou, Zhengyi Jiang
Faculty of Engineering and Information Sciences - Papers: Part A
Micro forming of metals has drawn global attention due to the increasing requirement of micro metal products. However, the size effects become significant in micro forming processes and affect the application of finite element (FE) simulation of micro forming processes. Dividing samples into small areas according to their microstructures and assigning individual properties to each small area are a possible access to micro forming simulation considering material size effects. In this study, a new model that includes both grains and their boundaries was developed based on the observed microstructures of samples. The divided subareas in the model have exact shapes …
Finite Element Method Analysis Of Surface Roughness Transfer In Micro Flexible Rolling, Feijun Qu, Haibo Xie, Zhengyi Jiang
Finite Element Method Analysis Of Surface Roughness Transfer In Micro Flexible Rolling, Feijun Qu, Haibo Xie, Zhengyi Jiang
Faculty of Engineering and Information Sciences - Papers: Part A
Micro flexible rolling aims to fabricate submillimeter thick strips with varying thickness profile, where the surface quality of products is mainly determined by initial workpiece surface roughness and subsequent surface asperity flattening process, which is affected by process parameters during rolling. This paper shows a 3D finite element model for flexible rolling of a 250 μm thick workpiece with reduction of 20 to 50%, and rolling phase with thinner thickness indicates a better ability to decrease the surface roughness. Four types of initial workpiece surface roughness are studied in the simulation, and the influences of process parameters, such as friction …
An Experimental And Numerical Investigation On Micro Rolling For Ultra-Thin Strip, Haibo Xie, Kenichi Manabe, Tsuyoshi Furushima, Kazuo Tada, Zhengyi Jiang
An Experimental And Numerical Investigation On Micro Rolling For Ultra-Thin Strip, Haibo Xie, Kenichi Manabe, Tsuyoshi Furushima, Kazuo Tada, Zhengyi Jiang
Faculty of Engineering and Information Sciences - Papers: Part A
The demand for miniaturized parts and miniaturized semi-finished products is increasing nowadays, because microforming processes can improve production rate and minimize material waste due to less forming passes. However, traditional macro metal forming processes and modelling cannot be simply scaled down to produce miniaturized micro parts. In this study, a 2-Hi micro rolling mill has been successfully built. Experimental and numerical investigations on the micro rolling process for ultra-thin SUS 304 stainless steel strip have been conducted. The experimental results show that the micro rolling deformation of ultra-thin strip is influenced by size effect which results from the specimen size …
Lubrication Characterisation Analysis Of Stainless Steel Foil During Micro Rolling, Haibo Xie, Kenichi Manabe, Tsuyoshi Furushima, Kazuo Tada, Zhengyi Jiang
Lubrication Characterisation Analysis Of Stainless Steel Foil During Micro Rolling, Haibo Xie, Kenichi Manabe, Tsuyoshi Furushima, Kazuo Tada, Zhengyi Jiang
Faculty of Engineering and Information Sciences - Papers: Part A
Physical parameters, such as microscopic and roughness, play important roles in microforming process due to an increasing ratio of surface to volume of the deformed material. The study on lubrication characterisation in microforming is getting more attractive to researchers because traditional models are not reliable in this scaled down process. In this study, the micro rolling deformation characterisation has been investigated on SUS 304 stainless steel considering lubricant effect and feature size effect. The foil thickness plays an important role in the tribological features of micro rolling. The evolutions of both oil film thickness and foil surface are analysed accordingly. …