Using micro deep drawing with ironing stages to form stainless steel 304 micro cups

2013 ◽  
Vol 15 (2) ◽  
pp. 298-305 ◽  
Author(s):  
Jenn-Terng Gau ◽  
Sujith Teegala ◽  
Kun-Min Huang ◽  
Tun-Jen Hsiao ◽  
Bor-Tsuen Lin
2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Jingwei Zhao ◽  
Tao Wang ◽  
Fanghui Jia ◽  
Zhou Li ◽  
Cunlong Zhou ◽  
...  

AbstractIn the present work, austenitic stainless steel (ASS) 304 foils with a thickness of 50 µm were first annealed at temperatures ranging from 700 to 1100 ℃ for 1 h to obtain different microstructural characteristics. Then the effects of microstructural characteristics on the formability of ASS 304 foils and the quality of drawn cups using micro deep drawing (MDD) were studied, and the mechanism involved was discussed. The results show that the as-received ASS 304 foil has a poor formability and cannot be used to form a cup using MDD. Serious wrinkling problem occurs on the drawn cup, and the height profile distribution on the mouth and the symmetry of the drawn cup is quite non-uniform when the annealing temperature is 700 ℃. At annealing temperatures of 900 and 950 ℃, the drawn cups are both characterized with very few wrinkles, and the distribution of height profile, symmetry and mouth thickness are uniform on the mouths of the drawn cups. The wrinkling becomes increasingly significant with a further increase of annealing temperature from 950 to 1100 ℃. The optimal annealing temperatures obtained in this study are 900 and 950 ℃ for reducing the generation of wrinkling, and therefore improving the quality of drawn cups. With non-optimized microstructure, the distribution of the compressive stress in the circumferential direction of the drawn foils becomes inhomogeneous, which is thought to be the cause of the occurrence of localized deformation till wrinkling during MDD.


2021 ◽  
Vol 2020 (1) ◽  
pp. 012040
Author(s):  
S N Yuan ◽  
H B Xie ◽  
F H Jia ◽  
H Wu ◽  
D Pan ◽  
...  

2021 ◽  
Author(s):  
Di Pan ◽  
Guangqing Zhang ◽  
Fanghui Jia ◽  
Hamidreza Kamali ◽  
Yao Lu ◽  
...  

Abstract Micro deep drawing is a process to manufacture the thin walled, hollow, box or cup like products at micro scale. Lubricant can affect the products’ quality in micro deep drawing at micro scale due to the decrease of coefficient of friction between the material and tools, it is crucial to enhance the forming efficiency. In this study, 40 µm thickness stainless steel 301 (SUS301) was annealed at 980 ℃ for 2 min under protection of argon gas ambient, and this stainless steel was selected as the specimen material. The micro deep drawing was conducted on a micro press machine under dry and 4% TiO2 nanoparticle lubrication conditions with different forming velocities. The experimental results showed that the micro cup’s profile is affected by changing the forming velocity under the dry and nanoparticle lubrication conditions. Under the dry condition, the surface became rough with the increase of the forming velocity, and then the micro forming efficiency under application of nanoparticle lubricant increases with a rise of drawing velocity.


Author(s):  
Ihsan Irthiea ◽  
Zaid Mahmood

Due to its simplicity, versatility of process and feasibility of prototyping, using flexible tools in sheet forming seems appropriate for producing cups at microscales. This article presents a novel micro deep drawing technique in which a cooperation of a floating ring, as a primary rigid die, with a rubber pad, as a main flexible die, is employed for forming micro-cups. The function of the floating ring is to overcome minor wrinkles that commonly occur at flange portion, while the flexible die is to complete the forming stroke. The influence of initial sheet thickness, drawing ratio, punch corner radius and rubber height is studied through simulations and experiments. Furthermore, three size scales are adopted to investigate the possibility of using the proposed technique under different process dimensions. The code ABAQUS/Standard is utilized to build the finite element models and thereafter micro-forming experiments are carried out to verify the numerical results. For this purpose, a special setup is developed to be compatible with simulation models. The results show that the formed cups are characterized by very accurate dimensions, high surface quality, homogeneous wall thickness distribution in terms of maximum thinning and thickening and relatively large aspect ratio.


2015 ◽  
Vol 661 ◽  
pp. 77-82
Author(s):  
Chao Cheng Chang ◽  
Han Sheng Chen

The study investigated the effect of grain size on the micro deep drawing of SUS304 stainless steel squares. Three stainless steel sheets with different thicknesses of 0.05 mm, 0.1 mm and 0.2 mm were treated by annealing processes at 1100 °C in which the holding times were varied in order to adjust the grain size. The sheets were used in the micro deep drawing processes for producing the square cups with 3 mm side length and 1.8 mm height. According to the design rules from references, the dimensions of the blank were determined to reduce the variation on the rim height of the square cup. The results showed that two peak values appeared on the load curves and the as-received sheet with the smallest grain size led to the largest load. Moreover, the cases of the as-received sheet with smaller grains had smoother surface textures than those of the annealed sheets with larger grains.


2018 ◽  
Vol 11 (2) ◽  
pp. 84-89
Author(s):  
Ahmed A. Zainulabdeen ◽  
Jabbar H. Mohmmed ◽  
Najmuldeen Y. Mahmood

Anisotropy of materials has harmful effects during deep drawing operations and reduce it will strongly enhance the productivity and quality of deep drawing yields. In this work the effect of annealing treatment on texture and anisotropy behavior of cold rolled stainless steel 304 sheets were investigated. Uniaxial tensile test samples cut at 0o, 45o and 90o to the rolling direction were prepared in order to measure the anisotropy parameters (normal anisotropy, r_n, and planar anisotropy, ∆r). Two annealing temperatures (1050, and 1150) °C were used to study their effects on anisotropy behavior. The results show that the normal anisotropy value of annealed samples at 1150°C increases by (31%) as compared to the received samples. This indicates that the annealed samples at 1150 °C have the highest formability. Also, results show significant reduction (about 88.7%) in planar anisotropy value for 1150°C annealed samples. This gave rise to an increase in deep drawing yield


2018 ◽  
Vol 190 ◽  
pp. 15001 ◽  
Author(s):  
Julien Kovac ◽  
Lukas Heinrich ◽  
Bernd Koehler ◽  
Andreas Mehner ◽  
Brigitte Clausen ◽  
...  

Al-Sc-Zr alloys are interesting for the production of high strength micro components by micro deep drawing. These alloys show a good hardenability due to the formation of nanometer-scale spheroidal Al3(Sc, Zr) precipitates, which are highly coherent with the aluminum matrix. However, the formation of these precipitates in Al-Sc-Zr foils fabricated by conventional metallurgical methods dramatically reduces their ductility and drawability. In this work, magnetron sputtering was used to produce Al-Sc-Zr foils and Al-Sc-Zr / stainless steel bimetallic foils which are nearly free of these precipitates. Tensile tests were carried out to measure and compare the mechanical properties of monometallic Al-Sc-Zr foils and bimetallic Al-Sc-Zr / stainless steel foils deposited with varying plasma target powers and containing different volume fractions (layer thickness) of Al-Sc-Zr. Micro deep drawing was used to determine the drawability of selected monometallic and bimetallic foils. The results show that the density of monometallic Al-Sc-Zr foils can be improved significantly by increasing the DC target power and by using the high power impulse magnetron sputtering (HiPIMS) technology, resulting in foils with higher ductility. Bimetallic foils achieved higher strength and ductility than monometallic Al-Sc-Zr foils. Their mechanical properties vary with the target power and the volume fraction (thickness) of Al-Sc-Zr. The limit drawing ratio of HiPIMS deposited monometallic foil was 1.7 or 1.8 depending on the side of the foil facing the die, whereas a limit drawing ratio of 1.9 was observed for bimetallic foils.


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