scholarly journals Mechanical Properties of Co-Extruded Aluminium-Steel Compounds

2017 ◽  
Vol 742 ◽  
pp. 512-519 ◽  
Author(s):  
Susanne Elisabeth Thürer ◽  
Johanna Uhe ◽  
Oleksandr Golovko ◽  
Christian Bonk ◽  
Anas Bouguecha ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Tests ◽  
Steel Tube ◽  
Research Centre ◽  
Tool Geometry ◽  
Case Hardening ◽  
Process Step ◽  
Process Chains ◽  
Ultrasonic Assisted ◽  
Case Hardening Steel

Within the scope of the Collaborative Research Centre (CRC) 1153 novel process chains for the production of hybrid solid components by Tailored Forming are developed at the Leibniz Universität Hannover. The combination of e. g. aluminium with steel allows to produce hybrid compounds with wear-resistant functional surfaces and reduced weight. In these process chains, joining takes place as the first step to produce hybrid semi-finished products by friction welding, cladding, ultrasonic assisted laser welding or co-extrusion, which are subsequently subjected to various forming processes such as forging or impact extrusion. The coaxially joined hybrid semi-finished components investigated in this work were produced by means of the lateral angular co-extrusion (LACE) process using the aluminium alloy EN AW-6082 and the case-hardening steel 20MnCr5. These semi-finished products shall be suited to produce hybrid bearing bushings by die forging in a subsequent process step. Initial investigations for the determination of the process parameters and the appropriate tool geometry were made using a steel rod. In future investigations, a steel tube will replace the steel rod in order to produce hybrid semi-finished products, which can be fully integrated into the process chain. The mechanical properties of the profile were determined at different positions along its length. For this purpose, the quality of the joining zone between aluminium and steel as a function of the profile position was examined by means of push-out tests. Moreover, the mechanical properties of the aluminium component’s longitudinal weld seam were determined by micro-tensile-tests.

scholarly journals Process chain for the manufacture of hybrid bearing bushings

2021 ◽  
Vol 15 (2) ◽  
pp. 137-150
Author(s):  
Susanne Elisabeth Thürer ◽  
Anna Chugreeva ◽  
Norman Heimes ◽  
Johanna Uhe ◽  
Bernd-Arno Behrens ◽  
...  
Keyword(s):  
Extrusion Process ◽  
Steel Tube ◽  
Case Hardening ◽  
Process Chain ◽  
Forming Process ◽  
Die Forging ◽  
Material Contact ◽  
Hybrid Bearing ◽  
Case Hardening Steel ◽  
Tailored Forming

AbstractThe current study presents a novel Tailored Forming process chain developed for the production of hybrid bearing bushings. In a first step, semi-finished products in the form of locally reinforced hollow profiles were produced using a new co-extrusion process. For this purpose, a modular tool concept was developed in which a steel tube made of a case-hardening steel, either C15 (AISI 1015) or 20MnCr5 (AISI 5120), is fed laterally into the tool. Inside the welding chamber, the steel tube is joined with the extruded aluminum alloy EN AW-6082. In the second step, sections from the compound profiles were formed into hybrid bearing bushings by die forging. In order to set the required forming temperatures for each material—aluminum and steel—simultaneously, a tailored heating strategy was developed, which enabled successful die forging of the hybrid workpiece to the desired bearing bushing geometry. Using either of the case-hardening steels in combination with aluminum, this novel process chain made it possible to produce intact hybrid bearing bushings, which showed both macroscopically and microscopically intimate material contact inside the compound zone.

Effect of Tool Parameters on Mechanical Properties of Friction Stir Welded Aluminum Alloy

2015 ◽  
Vol 786 ◽  
pp. 111-115 ◽  
Author(s):  
Srinivasa Rao Pedapati ◽  
G. Vimalan ◽  
Mokhtar Awang ◽  
A.M.A. Rani
Keyword(s):  
Mechanical Properties ◽  
Rotational Speed ◽  
Base Material ◽  
Hardness Test ◽  
Tensile Tests ◽  
Tool Geometry ◽  
Welding Parameters ◽  
Material Strength ◽  
Friction Stir ◽  
Tool Profiles

The mechanical properties of weld joints in Friction Stir Welding (FSW) are influenced by the welding parameters such as rotational speed, tool geometry and welding speed. In the present study, three different tool profiles have been used to weld the joints with three different rotational speed and two welding speeds. Full factorial experiments have been conducted using DoE. The mechanical properties of weld joint were evaluated by means of tensile tests and hardness test at room temperature. The experiment result shows that the average highest number of hardness was 40.06 HRB with square tool at a rotational speed of 2000rpm while lowest hardness was 30.84 HRB with cylindrical threaded tool at rotational speed of 1800rpm. The maximum tensile strength of the joint obtained is 265 M Pa which is close to base material strength. It is observed from experimental results that joints made by square tool yield more strength compared to other tool profiles.

scholarly journals Effect of Tool Geometry and Welding Speed on Mechanical Properties and Microstructure of Friction Stir Welded Joints of Aluminium Alloys AA6082-T6

2014 ◽  
Vol 61 (3) ◽  
pp. 455-468
Author(s):  
Hiralal Subhash Patil ◽  
Sanjay N. Soman
Keyword(s):  
Mechanical Properties ◽  
Welding Speed ◽  
Welded Joints ◽  
Aluminium Alloys ◽  
Tensile Tests ◽  
Tool Geometry ◽  
Welding Parameters ◽  
Friction Stir ◽  
Tool Pin Profile ◽  
Tool Pin

Abstract Friction stir welding is a solid state innovative joining technique, widely being used for joining aluminium alloys in aerospace, marine automotive and many other applications of commercial importance. The welding parameters and tool pin profile play a major role in deciding the weld quality. In this paper, an attempt has been made to understand the influences of welding speed and pin profile of the tool on friction stir welded joints of AA6082-T6 alloy. Three different tool pin profiles (tapered cylindrical four flutes, triangular and hexagonal) have been used to fabricate the joints at different welding speeds in the range of 30 to 74 mm/min. Microhardness (HV) and tensile tests performed at room temperature were used to evaluate the mechanical properties of the joints. In order to analyse the microstructural evolution of the material, the weld’s cross-sections were observed optically and SEM observations were made of the fracture surfaces. From this investigation it is found that the hexagonal tool pin profile produces mechanically sound and metallurgically defect free welds compared to other tool pin profiles.

scholarly journals Contact Geometry Modification of Friction-Welded Semi-Finished Products to Improve the Bonding of Hybrid Components

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 115
Author(s):  
Bernd-Arno Behrens ◽  
Johanna Uhe ◽  
Tom Petersen ◽  
Florian Nürnberger ◽  
Christoph Kahra ◽  
...  
Keyword(s):  
Tensile Tests ◽  
Case Hardening ◽  
Process Chain ◽  
Forming Process ◽  
X Ray ◽  
Front End ◽  
Transition Area ◽  
Hardness Tests ◽  
Bonded Joint ◽  
Case Hardening Steel

To improve the bond strength of hybrid components when joined by friction welding, specimens with various front end surface geometries were evaluated. Rods made of aluminum AA6082 (AlSi1MgMn/EN AW-6082) and the case-hardening steel 20MnCr5 (AISI 5120) with adapted joining surface geometries were investigated to create both a form-locked and material-bonded joint. Eight different geometries were selected and tested. Subsequently, the joined components were metallographically examined to analyze the bonding and the resulting microstructures. The mechanical properties were tested by means of tensile tests and hardness measurements. Three geometrical variants with different locking types were identified as the most promising for further processing in a forming process chain due to the observed material bond and tensile strengths above 220 MPa. The hardness tests revealed an increase in the steel’s hardness and a softening of the aluminum near the transition area. Apparent intermetallic phases in the joining zone were analyzed by scanning electron microscopy (SEM) and an accumulation of silicon in the joining zone was detected by energy-dispersive X-ray spectroscopy (EDS).

scholarly journals On the Q&P Potential of a Commercial Spring Steel

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1612
Author(s):  
Markus Härtel ◽  
Alisa Wilke ◽  
Sebastian Dieck ◽  
Pierre Landgraf ◽  
Thomas Grund ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Electron Backscatter Diffraction ◽  
Tensile Tests ◽  
Spring Steel ◽  
Process Window ◽  
Compression Tests ◽  
Process Step

Over the last years heat treatment concept of “quenching and partitioning” (Q&P) has reached popularity for its ability to precisely adjust material properties to desired values. Mostly, Q&P process are applied on tailor-made materials with high purities or prototype alloys. The research in hand presents the whole routine of how to investigate the potential of a commercial 0.54C-1.45Si-0.71Mn spring steel in terms of Q&P heat treatment from lab scale in dilatometer measurements to widely used inductive heat treatment on larger scale. In order to obtain the small process window for this material we were focusing on the interplay of the formed microstructure and the resulting mechanical properties in hardness measurements, compression tests as well as tensile tests. After full austenitizing, three different Q&P processing routes were applied. Microstructural analyses by optical microscopy, Scanning Electron Microscopy (SEM) and Electron Backscatter Diffraction (EBSD) exhibit a condition with 6.4 % and 15 % volume fraction of fine distributed retained austenite. Interestingly, the 15 % of retained austenite developed during the partitioning heat treatment. Contradictory to our expectations, tensile and compression testing were showing that the 6.4 % condition achieved improved mechanical properties compared to the 15 % retained austenite condition. The remarkable conclusion is that not only volume fraction and fine distribution of retained austenite determines the potential of improving mechanical properties by Q&P in commercial alloys: also the process step when the retained austenite is developing as well as occurring parallel formation of carbides may strongly influence this potential.

scholarly journals Analysis of the applicability of steel 20MnCrS5 for gears of the domestic mobile machines

2020 ◽  
pp. 44-49
Author(s):  
S. P. Rudenko ◽  
A. I. Valko ◽  
S. G. Sandomirskii
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Diffusion Layer ◽  
Physical And Mechanical Properties ◽  
Virtual Simulation ◽  
Alloying Elements ◽  
Case Hardening ◽  
European Standard ◽  
Case Hardening Steel ◽  
Maximum Limit

Evaluation of applicability of 20MnCrS5 steel for gears of transmissions of mobile machines, manufactured according to European standard EN 10084 was carried out. Experimental and virtual simulation of hardenability of the steel according to the updated method was realized. The assessment of the applicability of 20MnCrS5 case-hardening steel for gears of the domestic mobile machines was made by the criterion of obtaining the cross section of the tooth structures with a hardness 32 HRC for core, 50 HRC for semi-conversion zone, 61–63 HRC for the diffusion layer excluding other physical and mechanical properties of steel.It is established that at the content of alloying elements close to the maximum limit, the use of this steel is possible for gears with a module up to 10 mm.

AISI 4320

Alloy Digest ◽  
1959 ◽  
Vol 8 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Heat Treating ◽  
Case Hardening ◽  
High Toughness ◽  
Nickel Chromium ◽  
Steel Mills ◽  
Shock Resistance ◽  
Case Hardening Steel

Abstract AISI 4320 is a nickel-chromium-molybdenum case hardening steel having high toughness and shock resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-80. Producer or source: Alloy steel mills and foundries.

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