New Forming Processes for Sheet Metal with Large Plastic Deformation

2007 ◽  
Vol 344 ◽  
pp. 251-258 ◽  
Author(s):  
Peter Groche ◽  
Jens Ringler ◽  
Dragoslav Vucic
Keyword(s):  
Sheet Metal ◽  
Cross Sections ◽  
Lightweight Design ◽  
High Surface ◽  
Surface Hardness ◽  
Band Edge ◽  
Experimental Investigations ◽  
Large Strains ◽  
Linear Flow ◽  
Flow Splitting

Due to the high effort involved, bifurcated constructions in mass market products made from sheet metal remained largely unused. Extruded profiles with cross-sections containing bifurcations show the possibility to increase the stiffness and allow modern lightweight design using load optimized structures as well as in box strap, sandwich and stringer constructions or different profiles. The two new forming processes linear flow splitting and linear bend splitting developed at the PtU enable the production of bifurcated profiles in integral style made of sheet metal without joining, lamination of material or heating of the semi-finished product. These forming processes use obtuse angled splitting rolls and supporting rolls to transform the sheet metal at ambient temperature. Whereas the linear flow splitting process increase the surface of the band edge and forms the band into two flanges. At linear bend splitting a bended sheet metal as semi finished product is used. Thereby bifurcations at nearly any place of a sheet metal can be produced. Both processes induce high hydrostatic compressive stresses in the local forming zone during the process which leads to an increased formability of the material and thereby to the realization of large strains. Parts produced are characterized by increased stiffness, high surface hardness and low surface roughness. Experimental investigations have shown an increasing of the band edge surface at maximum splitting depth up to 1800%. By a following forming process new multi-chambered structures and integral stringer construction can be realized with thin walled cross-sections from steel of higher strength.

A Model for the Representation of Surface Roughness and Form Deviation in Geometry Models

2013 ◽  
Author(s):  
Oliver Weitzmann ◽  
Reiner Anderl
Keyword(s):  
Surface Roughness ◽  
Product Development ◽  
Surface Properties ◽  
Sheet Metal ◽  
Functional Integration ◽  
Higher Order ◽  
Linear Flow ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Flow Splitting

Functional integration and resource utilization are a challenge in today’s product development. The selective utilization of surface properties for functional integration offers potentials which aren’t exhausted until now. Surface roughness is mostly considered in manufacturing and measurement but the product properties impacted by surface roughness are determined in the product development. So it is necessary to integrate and extend the information about surface roughness in the methods and models of the product development. Therefore an approach for the representation of surface properties in product development is evolved. Based on the classification of surface deviation and profile courses, a method for building a surface profile is explored and depicted in an object-oriented representation model. One example for the functional integration and the use of technology-induced properties are sheet metal parts with higher order bifurcation in integral style. A new massive forming technology called linear flow splitting enables the manufacturing of sheet metal parts with higher order bifurcation in integral style. Within this manufacturing process, the material properties change heavily. Considering these changes in the product development, the representation model is needed to ensure the functionality. The model is used for generation a typical surface resulting from a linear flow splitting process.

Research on the influence of the band edge processing on the process of linear flow splitting

2015 ◽  
Vol 47 (1) ◽  
pp. 12-18 ◽  
Author(s):  
M. Neuwirth ◽  
L. Ahmels ◽  
S. Schmidt ◽  
M. Hegemann ◽  
P. Groche ◽  
...  
Keyword(s):  
Band Edge ◽  
Linear Flow ◽  
Flow Splitting

scholarly journals Fretting Wear Performance of PVD Thin Films

2020 ◽  
Author(s):  
Brahim Tlili
Keyword(s):  
Coefficient Of Friction ◽  
Normal Load ◽  
High Surface ◽  
Surface Hardness ◽  
Hard Coatings ◽  
Displacement Amplitude ◽  
Fretting Wear ◽  
Experimental Investigations ◽  
Multilayer Coatings ◽  
Ambient Conditions

Nowadays, most surface treatments are realized through vapor deposition techniques as thin hard coatings to guarantee high surface hardness, low friction coefficient, and improve wear resistance. Several experimental investigations have led to the development of multilayer coatings in preference to the traditional TiN coating. In the current chapter, research was conducted on the fretting wear of (TiAlCN/TiAlN/TiAl) and (TiAlZrN/TiAlN/TiAl) multilayer coatings deposited by reactive DC (magnetron sputtering) of Ti-Al and Ti-Al-Zr alloys on AISI4140 steel. Fretting wear tests (20,000 cycles at 5 Hz) were conducted in ambient conditions, where the interaction between normal load and displacement amplitude determined the fretting regime. The influence of the normal load and displacement amplitude on the coefficients of instantaneous coefficient of friction and stabilized coefficient of friction is different in the two multilayer, coated steels. The PVD coating (TiAlZrN/TiAlN/TiAl) reduces the friction. The worn volume of coated AISI4140 steel is sensitive to normal load and displacement amplitude. The relation between worn volume and cumulative dissipated energy was established for the two coated steels. The energetic fretting wear coefficients were also determined. A multilayer (TiAlZrN/TiAlN/TiAl) coating has a low energetic wear coefficient.

scholarly journals UFG-Microstructures by Linear Flow Splitting

2008 ◽  
Vol 584-586 ◽  
pp. 68-73 ◽  
Author(s):  
Clemens Müller ◽  
Tilman Bohn ◽  
Enrico Bruder ◽  
Peter Groche
Keyword(s):  
Mechanical Properties ◽  
Sheet Metal ◽  
Process Zone ◽  
Roll Forming ◽  
Microstructural Development ◽  
Cold Forming ◽  
Linear Flow ◽  
Flow Splitting ◽  
Processing Zone ◽  
Splitting Process

Linear flow splitting is a new continuous cold forming process where the edge of a sheet metal is formed into two flanges by splitting and supporting rolls. Thus the production of bifurcated profiles from sheet metal without lamination of material becomes feasible. The production of such structures takes place incrementally in a modified roll forming machine. Experimental investigateons on a HSLA steel show, that even at a surface increase of the sheet edge of about 1800% no cracks were nucleated in the profiles. EBSD measurements in the splitting centre reveal that similar to other SPD processes UFG microstructures develop in the processing zone. Thus a steady state is reached in the processing zone where increasing strain has no more (or little) influence on the materials properties i.e. its deformability, as it is typical for SPD-processes. The formation of UFG microstructures is considered to be a mandatory condition for the linear flow splitting process, as it improves the formability of the material to the extremely high level required for this process. The mechanical properties of profiles produced by linear flow splitting are characterised by large gradients, depending on the local deformation and the resulting microstructure. Very high hardness is measured at the former processing zone, i.e. the splitting centre and the flange surface, where severe plastic deformation takes place and UFG microstructures are present. In direction to lower deformation i.e. with increasing distance to the splitting ground or flange surface the hardness decreases close to the level of the undeformed material. In the present paper the linear flow splitting process is introduced and the microstructural development in the process zone is discussed on the base of EBSD measurements on profiles of the steel ZStE 500. The repartition of mechanical properties in a bifurcated profile is demonstrated by detailed hardness measurements.

Automated Import of XML-Files Containing Optimized Geometric Data to 3D-CAD-Models of Non-Linear Integral Bifurcated Sheet Metal Parts

2015 ◽  
Author(s):  
Thiago Weber Martins ◽  
Katharina Albrecht ◽  
Reiner Anderl
Keyword(s):  
Product Development ◽  
Sheet Metal ◽  
Data Model ◽  
Product Development Process ◽  
Linear Flow ◽  
Sheet Metal Parts ◽  
3D Cad ◽  
Geometric Data ◽  
Cad Models ◽  
Flow Splitting

The Collaborative Research Centre 666 has the focus on researching fundamental new methods for the development of optimized products and production processes for integral bifurcated sheet metal parts. Technological innovations have been achieved with respect to new production processes such as linear flow splitting and linear bend splitting as well as to produce products with flexible profiles. The use of state of art product development methodologies can be applied but these are not optimized to deal with the high complexity of the requirements and properties of integral bifurcated sheet metal products. In order to deal with that complexity a new approach of a product development methodology, the algorithm based product development process, has been established. Within the scope of the algorithm based product development methodology a topology optimization, based on mathematical algorithms using product requirements information, is already applied in the conceptual steps of product development process. By using this methodological approach an optimized concept of bifurcated sheet metal can be determined. The results are stored as optimized geometric data in XML-format files. 3D-CAD-Models are generated based on these data. However the import of these data into 3D-CAD-Systems are not fully automated. The developed data model, from earlier works for linear flow splitting and linear bend splitting, does not take into account the variability of the profiles in the third-dimension. In addition the topology optimization does not provide production-orientated design requirements and therefore it does not take into account the production process limits (of linear flow splitting and linear bend splitting). Hence 3D-CAD-Models resulting from the optimized geometric data need to be adapted manually. Therefore new advanced approaches in terms of virtual product development tools need to be explored. This paper describes the development of an interface within the CAD-System Siemens NX which supports the automatic import of XML-files containing the optimized geometric data of non-linear integral bifurcated sheet metal in 3D-CAD-Models. The existing data model is extended considering the requirements of the developed interface in order to represent nonlinear bifurcated profiles. An approach of the interface using the described data model and the NX Open API is introduced and explained.

NITRODUR 8524

Alloy Digest ◽  
2017 ◽  
Vol 66 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Fatigue Strength ◽  
Tensile Properties ◽  
High Temperatures ◽  
High Surface ◽  
Surface Hardness ◽  
Operating Temperatures

Abstract NITRODUR 8524 (8CrMo16, 1.8524) is one of the Nitrodur family of nitriding steels that are used where high surface hardness and good fatigue strength are required and the material is also subjected to high temperatures. Nitrided surfaces maintain their hardness and strength at operating temperatures of up to approximately 500–550 deg C (932–1022 deg F). This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on surface qualities as well as casting and forming. Filing Code: SA-807. Producer or source: Schmolz + Bickenbach Group.

DEUTSCHE EDELSTAHLWERKE CRYODUR 2067

Alloy Digest ◽  
2020 ◽  
Vol 69 (2) ◽  
Keyword(s):  
Cold Work ◽  
High Surface ◽  
Surface Hardness ◽  
Heat Treating ◽  
Chromium Alloy ◽  
Dimensional Changes ◽  
Short Run ◽  
Quench Hardening ◽  
Specialty Steel ◽  
Cold Work Tool Steel

Abstract Deutsche Edelstahlwerke Cryodur 2067 is a high-carbon, 1.5% chromium, alloy cold-work tool steel. In view of its higher hardenability than that of the non-alloy, water-hardening, cold work tool steels, this steel can be oil quenched, a factor that minimizes dimensional changes during quench hardening. Cryodur 2067 is suitable for short run tooling in applications requiring high surface hardness. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-786. Producer or source: Deutsche Edelstahlwerke Specialty Steel.

scholarly journals Interlocking birch plywood structures

2021 ◽  
pp. 095605992110222
Author(s):  
Chrysl A Aranha ◽  
Markus Hudert ◽  
Gerhard Fink
Keyword(s):  
High Surface ◽  
Surface Hardness ◽  
Experimental Tests ◽  
Digital Fabrication ◽  
Element Model ◽  
Component Level ◽  
Geometrical Properties ◽  
Stiffness Properties ◽  
The Face ◽  
Strength And Stiffness

Interlocking Particle Structures (IPS) are geometrically stable assemblies, usually fabricated from plate type elements that are interconnected by slotted joints. IPS are demountable and their components have the potential to be used and reused in different structures and configurations. This paper explores the applicability of birch plywood panels, which are characterized by a high surface hardness, for this type of structural system. Experimental tests were conducted to determine the mechanical properties of birch plywood plates. Moreover, IPS connections with different geometrical properties were investigated for two different load exposures: bending and rotation. The characteristics under bending exposure are influenced by the orientation of the face-veneers. For the rotational load exposure, very small strength and stiffness properties have been identified. A linear elastic finite element model is presented that shows a wide agreement with the test results. The study serves as an initial probe into the performance of IPS structures at the component level. Various aspects that are relevant for the design of IPS, such as the assembly, the accuracy and challenges regarding digital fabrication, the durability, and the structural performance are discussed.

Modelling and Analysis of Integrated Hotforming and Quenching Processes

2005 ◽  
Vol 6-8 ◽  
pp. 787-794 ◽  
Author(s):  
D. Lorenz ◽  
Karl Roll
Keyword(s):  
Lightweight Design ◽  
Experimental Investigations ◽  
Boron Steel ◽  
General Tendency ◽  
The Finite Element Method ◽  
Contact Heat ◽  
Simulation Accuracy ◽  
Structural Part ◽  
Component Strength ◽  
Structural Parts

In the automotive industry a general tendency to choose steels with enhanced strength for structural parts can be observed. This trend results from the increased lightweight design efforts to satisfy the fleet consumption restrictions. Hot forming and quenching of boron steel offers the possibility to improve the component strength and reduce the weight of structural parts. The main influences on the process are described and a method to model and simulate this process using the finite element method using LS-DYNA is presented. Experimental investigations of the contact heat transfer have been carried out to enhance the simulation accuracy. A prototyping tool of a structural part is used to examine the process under production conditions. Temperatures of the tool and the part are measured during the process. These temperatures are compared with the simulation results in order to reevaluate the results of the process simulation.

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