scholarly journals Effect of Rotational Speed on Static and Fatigue Properties of Rotary Friction Welded Dissimilar AA7075/AA5083 Aluminium Alloy Joints

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 99
Author(s):  
Agus Sasmito ◽  
Mochammad Noer Ilman ◽  
Priyo Tri Iswanto ◽  
Rifai Muslih
Keyword(s):  
Residual Stress ◽  
Aluminium Alloy ◽  
Base Metal ◽  
Weld Joint ◽  
Rotational Speed ◽  
Tensile Tests ◽  
Fatigue Properties ◽  
Weld Joints ◽  
Rotary Friction Welding ◽  
Welding Processes

In this work, rotary friction welding processes of dissimilar AA7075/AA5083 aluminium alloy rods with the diameter of 15 mm were performed at varying rotational speeds, typically 370 to 2500 rpm. The aim of this research is to improve mechanical properties, in particular, strength and fatigue performance of the weld joints. Several experiments including macro and microstructural examinations, Vickers microhardness measurements, tensile tests, fatigue tests and residual stress measurements were carried out. Results showed that at higher rotational speeds, typically 540 rpm or above, the dissimilar AA7075/AA5083 rotary friction weld joints revealed a static fracture in the AA5083 base metal side, indicating that the joint efficiency is more than 100%. It seemed that the best weld joint was achieved at the rotational speed of 1200 rpm, in which the friction heat was sufficient to form metallurgical bonding without causing excessive flash and burn-off. In such a condition, the fatigue strength of the weld joint was slightly higher than AA5083 base metal, but it was lower than AA7075 base metal. It was confirmed that the crack origin is observed at the interface followed by fatigue crack growth towards AA5083 side, and the growth of crack seemed to be controlled by microstructure and residual stress.

Influence of Rotary Friction Welding Parameters on Tensile Strength and Length of TMAZ of Dissimilar Welded Joints from 32G2 and 40KhN Steels

2021 ◽  
Vol 410 ◽  
pp. 299-305
Author(s):  
Artem S. Atamashkin ◽  
Elena Y. Priymak ◽  
Elena A. Kuzmina
Keyword(s):  
Tensile Strength ◽  
Base Metal ◽  
Process Parameters ◽  
Welded Joints ◽  
Friction Welding ◽  
Tensile Tests ◽  
Welding Parameters ◽  
Rotary Friction Welding ◽  
Study Results ◽  
Friction Pressure

In this work, pipe billets with a diameter of 73 mm and a wall thickness of 9 mm from steels 32G2 and 40KhN are friction welded with an aim to optimize the process parameters. The friction pressure, the forging pressure and the length of the fusion varied. After the implementation of various welding modes, tensile tests and metallographic studies were carried out. The optimal welding parameters have been established, which make it possible to obtain tensile strength at the level of the 32G2 base metal. The study results of the microstructure and SEM fractographs after the optimal welding mode are presented.

Role of welding processes on microstructure and mechanical properties of nuclear grade stainless steel joints

2019 ◽  
Vol 233 (11) ◽  
pp. 2335-2351 ◽  
Author(s):  
R Rajasekaran ◽  
AK Lakshminarayanan ◽  
M Vasudevan ◽  
P Vasantharaja
Keyword(s):  
Stainless Steel ◽  
Base Metal ◽  
Arc Welding ◽  
Gas Tungsten Arc Welding ◽  
Nuclear Grade ◽  
Lower Percentage ◽  
Weld Joints ◽  
Gas Tungsten Arc ◽  
Gas Tungsten ◽  
Welding Processes

Nuclear grade 316LN austenitic stainless steel weld joints were fabricated using conventional gas tungsten arc welding (GTAW), activated flux gas tungsten arc welding (AGTAW), laser beam welding (LBW) and friction stir welding (FSW) processes. Assessment of weld beads was done by mechanical and metallurgical characterizations. Bead geometry and weld zones were studied by taking macrographs along the transverse side of the weld joints. Metallurgical features of different weld joints were carried out using optical microscopy and scanning electron microscopy. Microhardness distribution across four weld joints was recorded and hardness variations were compared. All weld zone, heat affected zone (HAZ) of GTAW and LBW, thermo-mechanically affected zone (TMAZ) of FSW processes, exhibited higher hardness values than the base metal. Reduced hardness was recorded at HAZ of AGTAW process. This was the result of a considerable grain growth. LBW joint showed the highest hardness value at the center of the fusion zone due to fine equiaxed dendrite morphology. Tensile and impact properties of different welding processes were evaluated and comparisons were made at room temperature. All weld samples displayed high yield strength (YS) and ultimate tensile strength (UTS) with a lower percentage of elongation compared to that of the base metal. FSW joint showed improved YS, UTS and impact toughness compared to other weld joints. This is attributed to the formation of strain-free fine equiaxed grains at stir zone around 5 µm in size with subgrains of 2 µm in size by severe dynamic recrystallization mechanism. Among the fusion welding techniques, AGTAW process exhibited improved toughness, besides almost equal toughness of the base metal due to low δ-Ferrite with high austenite content. Fractography studies of the base metal and different weld samples were carried out by SEM analysis and features were compared.

Development of Residual Stress Improvement for Nuclear Pressure Vessel Instrumentation Nozzle Weld Joint (P-43+P-8) by Means of Induction Heating

2006 ◽  
Author(s):  
Takuro Terajima ◽  
Takashi Hirano
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Residual Stresses ◽  
Induction Heating ◽  
Weld Joint ◽  
Thermal Stresses ◽  
Pressure Vessels ◽  
Weld Joints

As a counter measurement of intergranular stress corrosion cracking (IGSCC) in boiling water reactors, the induction heating stress improvement (IHSI) has been developed as a method to improve the stress factor, especially residual stresses in affected areas of pipe joint welds. In this method, a pipe is heated from the outside by an induction coil and cooled from the inside with water simultaneously. By thermal stresses to produce a temperature differential between the inner and outer pipe surfaces, the residual stress inside the pipe is improved compression. IHSI had been applied to weld joints of austenitic stainless steel pipes (P-8+P-8). However IHSI had not been applied to weld joints of nickel-chromium-iron alloy (P-43) and austenitic stainless steel (P-8). This weld joint (P-43+P-8) is used for instrumentation nozzles in nuclear power plants’ reactor pressure vessels. Therefore for the purpose of applying IHSI to this one, we studied the following. i) Investigation of IHSI conditions (Essential Variables); ii) Residual stresses after IHSI; iii) Mechanical properties after IHSI. This paper explains that IHSI is sufficiently effective in improvement of the residual stresses for this weld joint (P-43+P-8), and that IHSI does not cause negative effects by results of mechanical properties, and IHSI is verified concerning applying it to this kind of weld joint.

scholarly journals Low Cycle Fatigue Properties of Alloy 617 base Metal and Weld Joint at Room Temperature

2014 ◽  
Vol 3 ◽  
pp. 2201-2206 ◽  
Author(s):  
Seon-Jin Kim ◽  
Pil-Ho Choi ◽  
Rando Tungga Dewa ◽  
Woo-Gon Kim ◽  
Min-Hwan Kim
Keyword(s):  
Base Metal ◽  
Weld Joint ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Alloy 617

Low Cycle Fatigue Properties of 316LN Stainless Steel Welded by GTAW in Nitrogen Added Environment

2007 ◽  
Vol 345-346 ◽  
pp. 275-278
Author(s):  
Dae Whan Kim ◽  
Chang Hee Han ◽  
Woo Seog Ryu
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Yield Strength ◽  
Base Metal ◽  
Weld Joint ◽  
Low Cycle Fatigue ◽  
Ferrite Content ◽  
Fatigue Properties ◽  
316Ln Stainless Steel ◽  
Type 316Ln Stainless Steel

Tensile and fatigue properties were evaluated for base and welded type 316LN stainless steel. Welding methods were GTAW (308L, Ar environment) and GTAWN (316L, Ar + N2 environment). Yield strength of weld joint was higher than that of base metal but elongation of weld joint was lower than that of base metal. UTS of weld joint was slightly lower than that of base metal. Yield strength and elongation with welding method were almost same. Fatigue life of weld joint was lower than that of base metal but fatigue strength of weld joint was higher than that of base metal. Ferrite content was increased with welding. Fatigue life welded by GTAWN was better than that of GTAW at RT and 600°C. This fatigue life behavior was consistent with the behavior of ferrite content.

Fatigue Crack Initiation Mechanism of Aluminium Alloy Welded Joint in Gigacycle Fatigue

2013 ◽  
Vol 376 ◽  
pp. 177-180
Author(s):  
Chao He ◽  
Shi Ming Cui ◽  
Yan Zeng Wu ◽  
Ze Fu Luo ◽  
Qing Yuan Wang
Keyword(s):  
Fatigue Crack ◽  
Crack Initiation ◽  
Aluminium Alloy ◽  
Fusion Zone ◽  
Base Metal ◽  
Welded Joint ◽  
Fatigue Crack Initiation ◽  
Fatigue Properties ◽  
Initiation Mechanism ◽  
Ultrasonic Fatigue

Ultrasonic fatigue test was performed on 5052 aluminium alloy welded joint to investigate the very high cycle fatigue properties and the fatigue crack initiation mechanisms with the help of microhardness tester and scanning electron microscope (SEM). The results showed that the hardness of fusion zone was higher that base metal and heat affected zone, which led to the embrittlement of welded zone. Fusion zone became the weakest part of welded joint under cyclical loading. Fatigue crack usually initiated from the pores beneath the surface from the SEM observation of fracture surface. The influence of pores on the fatigue crack initiation was analyzed to figure out the deterioration of fatigue strength for welded joint as compared with base metal.

Residual Stresses in As-Welded Joints: Finite Element Modeling and Neutron Difraction Stress Measurements

2011 ◽  
Vol 488-489 ◽  
pp. 335-338 ◽  
Author(s):  
Claire Acevedo ◽  
Jean Marie Drezet ◽  
J. P. Lefebvre ◽  
Laurent D'Alvise ◽  
A. Nussbaumer
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Arc Welding ◽  
Analysis Method ◽  
Weld Joints ◽  
Stress Components ◽  
Bridge Joints ◽  
Nonlinear Transient ◽  
Welding Processes

This paper describes the numerical analysis method used to estimate welding induced residual stresses in K-shape tubular bridge joints. The knowledge of residual stress distribution is required to design the geometry of K-joints loaded under fatigue stresses. Numerical simulations are focused on the arc welding MAG process, generally used to weld joints in bridge construction. Thermo-mechanical analyses are performed in 3D using two finite element codes:ABAQUS® and MORFEO® . ABAQUS has the advantage to offer large analysis capabilities(nonlinear, transient, dynamic, etc.) whereas MORFEO is more dedicated to welding processes and offers the possibility to analyze crack propagation under fatigue loads. Computed residual stresses in the region surrounding the weld are compared with measured residual stresses in order to estimate the ability of the codes to reproduce these stresses. Position, orientation and magnitude of the highest residual stress components are discussed.

Comparative assessment on weldability of Al 6061 to polycarbonate for dissimilar sheets placement in friction stir lap welding using sensor signals

2021 ◽  
pp. 095440622110426
Author(s):  
Nisith Goswami ◽  
Kamal Pal
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Rotational Speed ◽  
Weight Ratio ◽  
Weld Interface ◽  
Fusion Welding ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Joint Efficiency ◽  
Welding Processes

The thermoplastic polymers and precipitation hardened aluminium alloys are highly popular in the aerospace and automobile sectors as a replacement of metallic materials to improve the strength to weight ratio. Thus, the unlike aluminium alloy to polycarbonate assembled structures are often necessary for which mechanical fastening and adhesive bonding are the primary methods for joining as fusion welding processes are inadequate. However, the dissimilar joint efficiency is found to be less. Thus, the ultrasonic and friction welding processes are developed. The friction stir welding is one such advanced material stirring technique without any melting of base materials. The present work addresses metallic aluminium (Al6061) to polycarbonate sheet materials joining using friction stir welding in overlap configuration using tapered H13 tool steel. The thrust force with associated tool stirring torque has been acquired in real time during plunging followed by welding phase. The weld bead profile with respective force-torque signals was analysed for the process monitoring. The tensile test has been carried out on the lap welds. The weld interface of the unlike sheets have also been scrutinised. Initially, the aluminium sheet was partially overlapped on polycarbonate for the parametric study. The highest joint efficiency was found to be 40.2% at 1400 rpm tool rotational speed and 75 mm/min traverse speed due to improper material mixing at the weld interface. Therefore, the feasibility of the process have been tested by placing thermoplastic polycarbonate over aluminium alloy through which the joint efficiency was further improved (48.57%) at comparatively low tool rotational speed (1100 rpm) with lower welding speed (55 mm/min) as the minute metallic particles uniformly mixed with melted and solidified polycarbonate due to more uniform torque in the welding phase. The tool stirring torque and axial thrust was found to be higher in this overlap position.

Experimental Analysis of Residual Stress in Friction Stir Processed Cast AlSi9Mg Aluminium Alloy

2016 ◽  
Vol 682 ◽  
pp. 18-23 ◽  
Author(s):  
Marek Stanisław Węglowski ◽  
Piotr Sedek ◽  
Carter Hamilton
Keyword(s):  
Residual Stress ◽  
Aluminium Alloy ◽  
Rotational Speed ◽  
Parent Material ◽  
Tool Geometry ◽  
Friction Stir ◽  
Compressive Stresses ◽  
Longitudinal Residual Stress ◽  
Stress Profiles ◽  
The Relationship

The relationship between friction stir processing (FSP) parameters and longitudinal residual stress profiles in modified cast aluminium alloy AlSi9Mg is presented. The influence of tool geometry, rotational speed and the number of processing passes were analysed. To experimentally measure residual stress, the trepanation method was adopted. The results indicated that an increase in the rotational speed caused an increase in the residual stress. Also, the Triflute tool promoted a higher level of residual stress than a conventional FSP tool. The region around the FSP bead was characterised by tensile residual stress fields that were balanced by compressive stresses in the parent material. A higher residual stress is observed on the advancing side than on the retreating side. An increase in the number of processing passes increased the level of residual stress in the modified material.

Sign in / Sign up

Export Citation Format

Share Document