Papers by Keyword: Ironing

Abstract: Most forming oils have changed to chloride-free oil containing no chloride additives to protect environments regarding as the big issue of sustainable manufacturing. Several high-performance oil without chloride and die coating has been developed recently. In this study, the effect of micro-dimples on a die formed by a cutting machine or a laser device was tried to use chloride-free oil for ironing of stainless steel. The heavy galling occurred during ironing of stainless steel when the normal die without micro-dimples is used under a condition lubricated with chloride-free oil. The micro-dimples formed by the cutting machine only promoted galling because a large amount of burr remained around the dimples. The micro-dimples formed by the ultrashort pulse laser prevent from galling. The dimples have a smooth and mild profile on the die. The coverage area ratio of micro-dimples larger than 20% is needed for better ironing. A zigzag arrangement of the dimples uses the oil efficiently for well lubrication because galling occurs at the no dimples line between two rows of dimples if the dimples are neatly arranged parallel to the ironing direction.

Abstract: This study aims to evaluate the functionality and effectiveness of a new tool for ironing 3D printed components using FDM technology. The ironing process draws inspiration from the ball burnishing process, employing a spherical tool that, by exerting pressure, modifies the component's surface. The process involves heat transfer between the tool and the component to soften and deform the surface more easily. A theoretical analysis of the resulting surface roughness following this process was conducted to identify the parameters at play and their influence. It was found that the two main parameters are the fillet radius and the distance between passes. Additionally, practical tests were carried out to confirm the hypotheses, revealing the influence of three other parameters: tool Z-axis positioning, temperature, and movement speed. The surface after treatment exhibits an average roughness of Ra = 0.378 μm, significantly better than values obtained with ironing performed with the nozzle and with quality comparable to grinding. This lays the groundwork for possible future optimization of parameters based on the component's characteristics and the material used.

Abstract: This paper describes the tribological investigation of the cold forming and ejection process during ironing of hollow components with helical internal geometry. The experimental tests on a test tool are intended to evaluate the tribological system by varying the surface pretreatment of the blanks and the lubricant. For the evaluation of the tribological effects the ironing and ejection force are measured. In addition, the die filling as well as the surface quality of the pressed parts are determined, allowing the correlation of the test results with the tribological conditions. Furthermore, a numerical investigation of the process was performed. The numerical results are presented and compared with the experimental results.

Abstract: Oil with a chlorinated extremely-pressure additive (EP-additive) is effective to prevent galling in cold forming for stainless steel. However environmental issues have pressured the manufacture to replace this oil with high performance oil without chloride. Particularly, sulfur-based EP-additives are accepted as a practicable replacement for chlorinated EP-additives. Thus, the authors analyzed the structures of organic-sulfur compounds. Moreover, the effects of the molecular structures on the anti-galling performance are estimated by a cup internal ironing test. This test has been devised to classify the performance of sample oils by the ironing load and the damage on the workpiece after the test. Consequently, sulfurized olefin was superior to sulfurized ester and sulfurized fatty oil in cold ironing for stainless steel. It was also clarified that sulfur EP-additives generated iron sulfide and sulfate on the surface of stainless steel by using the surface analyses of X-ray photoelectron spectroscopy.

Abstract: This paper presents a new stretch forming method that applies compressive force for forming a deep cup with a flange. In this method, a punch and a die having a hole are used, and the main parameters are the depth of the die hole, d_dh, and the clearance between the punch and the die, c. The effect of d_dh and c was investigated by using an aluminum blank of thickness 2 mm in an experiment and a finite element analysis (FEA). When d_dh was too small, the material flow could not be controlled appropriately, and when d_dh was too large, a local thinning occurred during initial stretching into the die hole. When c was set at large, the side wall thickness of the formed cup was uneven, but a deep cup could be obtained by setting c below a half of the blank thickness. As a result, a deep cup of height 8.3 mm and with a flange was formed successfully under the condition that d_dh was 1.5 mm and c was 0.5 mm.

Abstract: This paper studied sizes and distribution of Fe-containing constituents in 3104 ingots, their breakage during subsequent rolling and the resultant influence on the final gauge sheet performance in ironing beverage cans. It was observed that coarse Fe-containing constituents had retained on the sheet surface from the ingot scalped by 7 mm per rolling face. They broke up during rolling by 7.5 times and mostly in reversing mill, but they still were coarse on the final gauge sheet that caused pitting formation on can side walls during ironing at body makers. The microstructure of the sheet rolled from 20 mm scalped ingot was fine and did not contain constituents over 20 μm in size that resulted in its robust performance at body makers. It was shown that Fe-containing constituents were extremely critical for the sheet microstructure and its subsequent ironing performance at body makers. The ingot scalping depth should be determined based on their sizes and distribution below the rolling faces to avoid coarse constituent remains on the sheet surface.

Abstract: In industrial practice, where the amount of products produced in a minute is calculated in hundreds of units, the ironing process of thin-walled cylindrical shell products is carried out with very high speed. In the multi-stage forming process it is important to ensure the stability of parameters of the raw material. Properties of input sheets are defined in international standards, but after the rolling process the properties of input tapes may be various while still in the acceptable tolerance. Differentiation of properties of sheets has a significant impact on the progress of the examined process. The multi-stage forming process requires raw material with a high susceptibility to deformation and an adequate level of plasticity margin. In this study tapes of equal thickness and similar chemical composition from various suppliers have been analyzed. Selected aluminum alloys sheet are currently used in Europe in production of beverage packaging. On the basis of uniaxial tension test results, plasticity margin for a selected tape has been determined. Deformation range and plasticity margin have been analyzed in relation to the stability of production process Defining the correlation between identified strength parameters and the stability of production line allowed to examine the impact of plasticity margin for effectiveness and efficiency of the process. In mass production, each break in machine work results in loss of millions of units. The analysis allowed to compare the value of plasticity indicators of the raw tape deformability in the complex process of forming thin-walled cylindrical shell products and influence for increase the efficiency and reduction of defects.

Abstract: The objective of this work is to investigate the tribological behavior between WC-Co cemented carbide and austenitic stainless steel under repeated rotation sliding. Influences of cobalt content of commercial grade cemented tungsten carbide on friction coefficient and material transfer phenomena have been explored. Three grades of commercial WC-Co cemented carbide with similar medium WC grain size were employed; WC-12Co, WC-14Co and WC-19Co. The average grain size were ranges between 0.85-1.1 μm and the hardness of about 86-88 HRA have been given by the material maker. The composition analysis and the average grain size of tungsten carbide have been rechecked. Furthermore, the carbide grain size distribution was recorded and the fracture toughness was calculated for each WC-Co grade. The experiments were carried out using ball on disk test. The ball was made from SUS304 grade and the disk was fabricated by 3 grades of WC-Co cemented carbide. The friction coefficient was measured under dry sliding. The characteristics of contact surfaces were explored on the ball as well as on the disk after tests to reveal the presence of a metallic transfer on the WC-Co cemented carbide disk and the wear scar on the ball. The measurement results of wear volume on the stainless steel ball disclosed that maximum wear rate was found from the stainless steel ball rub against WC-19Co tool material.

Abstract: Manufacturing of beverage cans is porcessed by using multi-stage ironing following deep drawing from the sheet material of aluminum and steel. An earing profiles are develops during deep drawing of cylindrical cup due to the planar anisotropic properties of sheet. Therefore, the analysis of earing is important to evaluate and control the development of earing. This paper describes a simulation of the cold ironing process in the forming cylinder cap. The ironing process in this study was focused on the prediction of height increasing, earing and thinning. Two different materials of aluminum AA5042 and AKDQ steel were selected for comparison. The results show that the increasing of cup height was in the same trend.

Abstract: Matrix cone angle is an important parameter in the ironing stretch process of two-piece can body. On the base of analyzing the ironing stretch technology, finite element simulation method with ABAQUS software was applied to simulate ironing stretch process of can body, the influence of matrix cone angle on ironing stretch technology was analyzed quantitatively, and then the reasonable range of matrix cone angle was recommended. The result indicated that the best range of matrix cone angle is 6°~9°, which can provide reference for the mould optimization and technology formulation.