scholarly journals Experimental investigation of the weldability of high strength aluminium using friction spot welding

2016 ◽  
Vol 7 (1) ◽  
pp. 8 ◽  
Author(s):  
T. Kolba ◽  
Koen Faes ◽  
Wim De Waele
Keyword(s):  
Spot Welding ◽  
Mechanical Performance ◽  
Rotation Speed ◽  
High Strength ◽  
Industrial Applications ◽  
Frictional Heat ◽  
Friction Spot Welding ◽  
Depth Rotation ◽  
Static Tensile ◽  
Specific Material

Friction spot welding is a technique for joining lightweight aluminium and magnesium alloys in the overlap configuration by means of frictional heat and mechanical work and has a high potential for industrial applications. As this is a very recent technique, little information is available regarding the evaluation and optimisation of process parameters for specific material combinations. The process has been used to investigate the weldability of the high strength aluminium alloy EN AW-7475-T761, aiming to produce high quality joints in terms of mechanical performance and microstructure. More specific, the influence of the plunge depth, rotation speed and welding time was investigated. The paper first shortly describes the process and continues with the results of the microhardness, static tensile and optical microscopy tests.

scholarly journals Metallographic evaluation of the weldability of high strength aluminium alloys using friction spot welding

2017 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Jeroen Vercauteren ◽  
Koen Faes ◽  
Wim De Waele
Keyword(s):  
Aluminium Alloys ◽  
Spot Welding ◽  
High Strength ◽  
Frictional Heat ◽  
Friction Spot Welding ◽  
Lap Shear ◽  
Spot Joining ◽  
Published Research ◽  
Interface Imperfections ◽  
Welding Technique

Friction spot welding is a recent solid-state welding technique well suited for spot-joining lightweight materials in overlap condition. Aerospace and transport industries show great interest in this technique to join high-strength aluminium alloys, but published research is still limited. In this project, the link between process parameters and weld quality is investigated for EN AW-7075-T6 material. Techniques used are metallographic qualification, measurement of hardness reduction and lap shear strength. This paper focusses on the metallographic investigation of the weld region and its imperfections. Increasing joining time and heat input creates an easier material flow resulting in fewer imperfections. Limited plunge depths lead to typical interface imperfections. Variation in the rotational speed shows distinctive stir zone shapes as a consequence of severe stirring and frictional heat.

scholarly journals Microstructure and Properties of Spot Welded Joints of Hot-Stamped Ultra-High Strength Steel Used for Automotive Body Structures

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 285 ◽  
Author(s):  
Zhixia Qiao ◽  
Huijun Li ◽  
Lianjin Li ◽  
Xiaoyu Ran ◽  
Liwen Feng
Keyword(s):  
Spot Welding ◽  
Mechanical Performance ◽  
High Strength Steels ◽  
High Hardness ◽  
High Strength ◽  
Resistance Spot ◽  
Automotive Body ◽  
Ultra High Strength Steels ◽  
Structural Parts ◽  
Spot Welded

Hot-stamped ultra-high strength steels have been widely used in automobile structural parts. Considering the high splash tendency in resistance spot welding due to their extremely high hardness, in this work, microstructural characteristics and mechanical performance of the resistance spot welded ultra-high strength steels are investigated. The results indicate that the interface between the nugget and heat-affected zone (HAZ) is the weakest zone where fractures initiate. In tensile shearing tests, a qualified spot welding joint failed with a button-shaped fracture. Welding defects would significantly decrease the load-carrying capacity and lead to interfacial fracture, except for a button-shaped fracture. In spot welding, it was found that a specific mid-frequency alternating current (AC) input mode, in which a 6 ms cooling cycle was inserted between every two neighboring current pulses, can avoid the splash in the spot welding of hot-stamped hardened steels.

Preliminary Investigation on Friction Spot Welding of AZ31 Magnesium Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 3016-3021 ◽  
Author(s):  
L.C. Campanelli ◽  
U.F.H. Suhuddin ◽  
Jorge Fernandez Dos Santos ◽  
N.G. Alcantara
Keyword(s):  
Magnesium Alloy ◽  
Spot Welding ◽  
Welding Process ◽  
High Energy ◽  
Az31 Magnesium Alloy ◽  
Frictional Heat ◽  
Welding Parameters ◽  
Friction Stir ◽  
Friction Spot Welding ◽  
Lap Shear

Friction spot welding (FSpW) is a recent solid state welding process developed and patented by GKSS Forschungszentrum (now Helmholtz-Zentrum Geesthacht), Germany. A spot-like connection is produced by means of an especially designed non-consumable tool consisting of pin, sleeve and clamping ring that creates a joint between sheets in overlap configuration through frictional heat and plastic deformation. FSpW offers many advantages over conventional spot joining techniques including high energy efficiency, surface quality and environmental compatibility. Comparing with friction stir spot welding, FSpW produces a weld without keyhole on the surface at the end of the joining process. In the present study, the possibility of joining AZ31 magnesium alloy by FSpW technique was evaluated by using different welding parameters (rotational speed, plunge depth and dwell time), aiming to produce high quality connections. Microstructural features were analyzed by light optical microscope and mechanical performance was investigated by microhardness test and lap shear test. Microstructure analysis revealed that defects free welds could be produced. A slight decrease in grain size of the stir zone was observed causing a slight increase in the microhardness of this region. The preliminary lap shear data demonstrated that the weld strength is comparable to other welding process.

AA5052 sheets welded by protrusion friction stir spot welding: High mechanical performance with considering sheets thickness at low dwelling time and tool rotation speed

2019 ◽  
Vol 233 (16) ◽  
pp. 5836-5847 ◽  
Author(s):  
N Farmanbar ◽  
SM Mousavizade ◽  
M Elsa ◽  
HR Ezatpour
Keyword(s):  
Mechanical Properties ◽  
Spot Welding ◽  
Dwell Time ◽  
Mechanical Performance ◽  
Rotation Speed ◽  
Peak Load ◽  
Friction Stir Spot Welding ◽  
Friction Stir ◽  
Tool Rotation Speed ◽  
Tool Rotation

In the present work, AA5052 sheets with thickness of 1 mm were successfully welded by protrusion friction stir spot welding as a low cost single-step method with a simple design that produces the no-keyhole joints with special mechanical properties at short dwell time and low tool rotation speed. By using suitable process parameters, the process is able to produce welds with superior mechanical performance in items of peak load and energy absorption compared to other techniques. The plunging depth and dwell time in this method were set as 0.2 mm and 6 s, respectively. The tool rotation speed was changed as 500, 800, 1250, and 1600 r/min to determine the optimum condition based on the microstructural and mechanical properties. Welds strength produced by the protrusion friction stir spot welding was directly related to the joint thickness, and the effective thickness of the upper sheet was maximum at 500 r/min. Protrusion friction stir spot welding joints presented circumferential failure mode after tensile shear testing. Regarding the sheets thickness used in this study, the joints produced by the current work presented high load bearing ability at dwell time of 6 s and tool rotation speed of 500 r/min compared to other techniques.

Microstructure of resistance spot welding of maraging steels

1990 ◽  
Vol 48 (4) ◽  
pp. 900-901
Author(s):  
I. Neuman ◽  
S.F. Dirnfeld ◽  
I. Minkoff
Keyword(s):  
Maraging Steel ◽  
Spot Welding ◽  
Lath Martensite ◽  
Base Material ◽  
Aging Treatment ◽  
High Strength ◽  
Maraging Steels ◽  
Heat Treated ◽  
Current Cycle ◽  
Welding Processes

Experimental work on the spot welding of Maraging Steels revealed a surprisingly low level of strength - both in the as welded and in aged conditions. This appeared unusual since in the welding of these materials by other welding processes (TIG,MIG) the strength level is almost that of the base material. The maraging steel C250 investigated had the composition: 18wt%Ni, 8wt%Co, 5wt%Mo and additions of Al and Ti. It has a nominal tensile strength of 250 KSI. The heat treated structure of maraging steel is lath martensite the final high strength is reached by aging treatment at 485°C for 3-4 hours. During the aging process precipitation takes place of Ni3Mo and Ni3Ti and an ordered solid solution containing Co is formed.Three types of spot welding cycles were investigated: multi-pulse current cycle, bi-pulse cycle and single pulsle cycle. TIG welded samples were also tested for comparison.The microstructure investigations were carried out by SEM and EDS as well as by fractography. For multicycle spot welded maraging C250 (without aging), the dendrites start from the fusion line towards the nugget centre with an epitaxial growth region of various widths, as seen in Figure 1.

SCHMELZMETALL HOVADUR CCZ

Alloy Digest ◽  
2020 ◽  
Vol 69 (9) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Spot Welding ◽  
Zirconium Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Softening Temperature ◽  
Aged Condition ◽  
Heat Treated ◽  
High Softening Temperature ◽  
Made In

Abstract Schmelzmetall Hovadur CCZ is a heat-treatable, copper-chromium-zirconium alloy. In the solution heat-treated and artificially aged condition, this alloy exhibits high thermal and electrical conductivity along with high strength and a high softening temperature. Hovadur CCZ evolved from CuCr1 (CW105C), a precipitation-hardenable alloy first made in the 1930s for spot welding electrodes, for which strength and hardness at temperatures up to 500 °C (930 °F), as well as good electrical and thermal conductivity, are essential. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: Cu-912. Producer or source: Schmelzmetall AG.

scholarly journals Smoothing additive manufactured parts using ns-pulsed laser radiation

2021 ◽  
Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni
Keyword(s):  
Surface Roughness ◽  
Mechanical Performance ◽  
State Of The Art ◽  
Pulsed Laser ◽  
Industrial Applications ◽  
Laser Source ◽  
Pulsed Laser Radiation ◽  
Current State ◽  
The Impact

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.

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