scholarly journals Friction and Wear Behavior of Deep Drawing Tools Using Volatile Lubricants Injected Through Laser-Drilled Micro-Holes

JOM ◽  
2021 ◽  
Author(s):  
Gerd Reichardt ◽  
Manuel Henn ◽  
Paul Reichle ◽  
Georg Umlauf ◽  
Kim Riedmüller ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Deep Drawing ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Sheet Material ◽  
Surface Damage ◽  
Drilling Process ◽  
Mineral Oils ◽  
Tribological System ◽  
Micro Holes

AbstractIn deep drawing processes, the use of lubricants is mandatory in order to prevent wear on tools and surface damage to the formed sheet metal components. Here, frequently used lubricants are synthetic and mineral oils, emulsions, and waxes. However, these conventional lubricants have to be applied to the sheet material prior to the forming operation and removed afterwards by cleaning processes. Additionally, the lubricants often contain substances that are harmful to the environment and to human health. To counteract these economic and ecological disadvantages, research is currently being conducted on a novel tribological system. For this, volatile media such as liquid carbon dioxide and gaseous nitrogen are being used, and are introduced directly into the friction zones between the tool and the sheet metal material during deep drawing under high pressure through special laser-drilled micro-holes. This paper covers the latest investigations and findings regarding the design of flow-optimized micro-holes, the laser drilling process, the friction characterization on tool radii, and the tool wear to be expected when using the lubrication medium CO2.

scholarly journals Lubricant-free deep drawing using CO2 and N2 as volatile media injected through laser-drilled microholes

2018 ◽  
Vol 190 ◽  
pp. 14007
Author(s):  
Ehsan Zahedi ◽  
Christoph Woerz ◽  
Gerd Reichardt ◽  
Georg Umlauf ◽  
Mathias Liewald ◽  
...  
Keyword(s):  
Deep Drawing ◽  
Friction And Wear ◽  
Oil Lubrication ◽  
Liquid Carbon ◽  
Environment Friendly ◽  
Mineral Oils ◽  
Tribological System ◽  
The University ◽  
Intermediate Medium ◽  
Conventional Oil

Most metal forming processes use lubricants based on mineral oils as an intermediate medium to reduce friction and wear. To avoid the well-known drawbacks of oil lubrication, a novel and environment friendly lubrication system for deep-drawing processes was demonstrated at the University of Stuttgart. Liquid carbon dioxide and gaseous nitrogen are being used as volatile lubrication during the deep-drawing process, locally injected at high pressure through laser-drilled microholes. This new tribological system provides a significantly enlarged working range and at least 15% larger drawing depths compared to conventional oil lubrication.

scholarly journals Lubricant-free deep drawing using CO2 and N2 as volatile media injected through laser-drilled microholes

2019 ◽  
Vol 6 ◽  
pp. 11
Author(s):  
Ehsan Zahedi ◽  
Christoph Woerz ◽  
Gerd Reichardt ◽  
Georg Umlauf ◽  
Mathias Liewald ◽  
...  
Keyword(s):  
Deep Drawing ◽  
Friction And Wear ◽  
Oil Lubrication ◽  
Liquid Carbon ◽  
Environment Friendly ◽  
Mineral Oils ◽  
Tribological System ◽  
The University ◽  
Intermediate Medium ◽  
Conventional Oil

Most metal forming processes use lubricants based on mineral oils as an intermediate medium to reduce friction and wear. To avoid the well-known drawbacks of oil lubrication, a novel and environment friendly lubrication system for deep-drawing processes was demonstrated at the University of Stuttgart. Liquid carbon dioxide and gaseous nitrogen are being used as volatile lubrication during the deep-drawing process, locally injected at high pressure through laser-drilled microholes. This new tribological system provides a significantly enlarged working range and at least 15% larger drawing depths compared to conventional oil lubrication.

Development of a New Ecological Lubrication System for Sheet Metal Forming Based on CO2 in Liquid

2015 ◽  
Vol 651-653 ◽  
pp. 480-485 ◽  
Author(s):  
Markus Singer ◽  
Mathias Liewald ◽  
Anne Feuer
Keyword(s):  
Sheet Metal ◽  
Contact Area ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Sheet Material ◽  
Lubrication System ◽  
Blank Holder ◽  
Tribological System ◽  
Micro Holes

Ecological aims and political requirements today are increasing demands on lubricants in sheet metal forming and their impact on environment. For that reason, metal forming industry wants to reduce the amount of lubricants containing polluting additives with a long-term goal of avoiding lubrication entirely. Additionally, dry metal forming will reduce the cleaning steps after the forming operation. This paper shows a new tribological system in which lubrication is replaced by CO2 in a liquid state. Here, CO2 is expanding directly into contact area between workpiece and tool surface and changes its state from gas to solid. The combination of this particular dry ice as well as the pressure of approximately 57 atm affects resulting friction coefficient significantly. After forming operation, CO2 medium vaporizes and a dry component can be used immediately for the next process steps. In this case, the lubricant is applied directly into the contact area. Therefore, laser drilled micro holes are located in the contact area of the tool. Very first gained experimental results disclose such feasibility, the effects and the potential of this new lubrication system at that moment is based on strip draw tests. Different numbers of micro holes are examined to support blank holder pressure ranging between 5 MPa and 6 MPa. In this investigation a mild strength steel DC04 is used as sheet material. This knowledge is aimed to be used for further investigation and later transfer into real deep and stretch forming processes.

scholarly journals IMPROVEMENT OF TECHNOLOGICAL PROCESS OF DRILLING THIN SHEET STEELS

2020 ◽  
pp. 48-54
Author(s):  
Anatoliy Ostrovsky
Keyword(s):  
Sheet Metal ◽  
Technological Process ◽  
Agricultural Sector ◽  
Sheet Material ◽  
Thin Sheet ◽  
Small Diameter ◽  
Main Tool ◽  
Drilling Process ◽  
Different Diameters ◽  
The Right

This article considers the technological process of drilling holes in sheet metal. The existing typical technological process, with detailed analysis, provides grounds for substantiating the idea of an innovative solution. There is a connection between the improvement of economic indicators of this technological operation with the change of geometric parameters of the tool. The comparison of existing technological processes, operations, and transitions of production of round openings with the use of spiral drills is given. The traditional technique involves a clear sequence of the technological process with the use of tools for marking, kerning, and sequential use of screw drills of different diameters. Therefore, after the previous operation of marking the center of the two holes, perform the operation of kerning. The core (recess in the metal) prevents the deviation of the small diameter screw drill from the marking lines. After the above steps, the traditional technological process involves drilling a small diameter hole in order to direct the main tool in the right direction. To make the main hole perform special sharpening of the working part of the twist drill so that the diameter of the Central part of the tool is equal to the diameter of the first guide hole to avoid further displacement of the main hole and the next operation is to drill the hole to the desired diameter. As a result, the article raises the topic, given the widespread use of sheet metal, including in the agricultural sector, the feasibility of using an innovative idea to improve the technological process associated with the processing of sheet material, namely thin metal sheets. It is worth noting that for example, we consider a material that is characterized by its versatility, namely steel Ст 3. Despite the numerous sources devoted to the study of improving the drilling process, there are a number of issues, including the extension of this direction surfaces with a covering and without it, various thicknesses within the thin-walled hire. The most significant result of the improved technological process of drilling will be used in the system of efficient maintenance of agricultural machinery.

scholarly journals Prediction and assessment of skid line formation during deep drawing of sheet metal components by using FEM simulation

2021 ◽  
Author(s):  
Patrick Cyron ◽  
Mathias Liewald ◽  
Kim-Rouven Riedmüller ◽  
Thanh-Lich Le
Keyword(s):  
Sheet Metal ◽  
Influencing Factors ◽  
Deep Drawing ◽  
Surface Defects ◽  
Sheet Material ◽  
Research Work ◽  
Fem Simulation ◽  
Subjective Perception ◽  
Forming Process ◽  
Research Activities

The subjective perception of the quality of sheet metal components mainly depends on geometric characteristics and surface structure. Additionally, particular attention must be paid in this context to avoiding surface defects such as skid lines during the sheet metal forming process. For this reason, current research activities focus on predicting such surface defects as precisely as possible in the early development stages of sheet metal components by using FEM simulation. However, the modelling approaches available today do not yet provide an adequate basis for such a numerical prediction regarding the appearance of surface defects of sheet metal components such as car body outer skin panels, especially of skid lines. Consequently, the research work reported about in this paper concentrates on the development of an empirical methodology for predicting and quantifying the formation of skid lines during deep-drawing processes by using FEM simulation. For this purpose, an experimental tool was developed to produce different skid line formations by using various process parameters and thus to investigate process-influencing factors on the example of the steel sheet material DC06. In principle, the investigations carried out showed that the punch radius and the blank holder force indeed do represent crucial influencing factors for the formation of skid lines. Finally, the results obtained were used to develop a forming simulation criterion, which allows predicting skid lines formations based on calculated strain state variables such as major strain, thinning and unbending strain.

Design of a Tribo-Simulator for the High Strength Steel Friction and Wear Investigation in Hot Stamping

2011 ◽  
Vol 421 ◽  
pp. 147-150 ◽  
Author(s):  
Xiao Wei Tian ◽  
Yi Sheng Zhang ◽  
Zheng Wang ◽  
Hong Qing Li ◽  
Liang Wang ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Coefficient Of Friction ◽  
High Strength Steel ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Hot Stamping ◽  
High Strength ◽  
Important Indicator ◽  
Hot Drawing ◽  
The Coefficient Of Friction

Hot stamping has become the main technology to produce complex-shaped high-strength steel components. However, hot sheet metal forming can cause high rates of die wear and the scratching of the productions. A hot drawing tribo-simulator was designed to investigate the friction and wear behavior of high strength steel at elevate temperature. The value of the friction coefficient was obtained to examine the function of the tribo-simulator. The results prove that the coefficient of friction in hot stamping can be measured using this tribo-simulator. Moreover, the coefficient of friction is able to be used in finite element simulation to improve the accuracy of the modeling results and it is also an important indicator to evaluate the tribological behavior between the die and sheet metal.

Simulation of Ironing Process for Earring Reduction in Sheet Metal Forming

2013 ◽  
Vol 465-466 ◽  
pp. 91-95 ◽  
Author(s):  
Agus Dwi Anggono ◽  
Waluyo Adi Siswanto
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Sheet Material ◽  
Anisotropic Properties ◽  
Multi Stage ◽  
Cylindrical Cup ◽  
And Control

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.

The anti-wear enhancement of boric acid + molybdenum disulfide derived tribofilm

2020 ◽  
pp. 135065012096027
Author(s):  
M Alper Yılmaz ◽  
Doğuş Özkan
Keyword(s):  
Boric Acid ◽  
Molybdenum Disulfide ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Lubricating Oil ◽  
Wear Loss ◽  
Metal Sulfate ◽  
Tribological System ◽  
Zinc Dithiophosphate ◽  
Harmful Content

Additives are important components to reduce friction and wear of tribological systems. Zinc dithiophosphate (ZDDP), the most commonly used anti-wear additive prevents the tribological system from the friction and wear loss without any commercially available antagonist additive. However, its environmentally harmful content enforces to lubricating oil manufacturers to replace it with an alternative one. Therefore, in this study, the H3BO3 + MoS2 combination was tested in the boundary lubrication regime in a tribometer with a pin on flat reciprocating test module to be a possible alternative anti-wear additive against ZDDP. The friction and wear behavior of Boric acid (H3BO3) + Molybdenum Disulfide (MoS2), ZDDP, MoS2, and H3BO3 evaluated in terms of friction coefficient (COF), wear rate, surface energy and tribo-chemical analysis of tribofilms. SEM/EDX and XPS were employed to explore tribofilm formations on the wear scars. According to the results, the addition of MoS2 into H3BO3 presented a similar tribological performance to ZDDP by forming a strength tribofilm on the surface containing B2O3, MoO3, and metal sulfate.

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