scholarly journals Friction welding of AISI 304: effect of friction time on micro-structure, micro-hardness and tension-compression properties

2020 ◽  
Vol 26 (3) ◽  
pp. 78-83
Author(s):  
Ammar JABBAR HASSAN ◽  
Taoufik BOUKHAROUBA ◽  
Djamel MIROUD

During direct drive friction welding could relatively predicting the micro-structural and mechanical properties of friction-welded joints by controlling the welding conditions; friction time is an important coefficient that effects on these properties, present study focused on the effect of that time on micro-structural and mechanical phenomena during that process. The process achieved in different friction time, while welding joints investigated by macroscope, microstructure, scanning electron microscope, tensile, compression and micro-hardness tests. The micro-hardness tests were performd along the interface and axial direction. Thus, the tensile tests  carried out on the standardized test piece with effective diameter of 6 mm and compression tests were extracted at welded center in three angles of 0°, 45° and 90° with test specimen of 4 mm diameter and 6.5 mm length. The results showed that with increasing friction time could be found hard zone at the interface of welded joint because of extended of high plastically deformation zone, which will responsible on decreasing some useful mechanical properties such as ultimate tensile strength and yield compression strength. However, tensile fracture position occurred adjacent to the interface at the thermo-mechanical deformation zone in the rotating side for all welding pieces, where the micro-hardness attenuated at that region.

2010 ◽  
Vol 146-147 ◽  
pp. 517-521
Author(s):  
Sheng Hui Xie ◽  
Xie Rong Zeng ◽  
Dong Ju Fu ◽  
Lei Zhao ◽  
Qiang Hu

Cu47.5Zr47.5Al5 bulk metallic glasses (BMGs) were cast from the melt temperature 1143 to 1373 K. The structure, thermal and mechanical properties of the BMGs were investigated by XRD, DSC, HRTEM, dilatometric measurements, micro-hardness tests and uniaxial compression. The results indicate that the microstructure and mechanical performance of BMGs are closely affected by the casting temperature. Proper casting temperature ensures the BMGs with large relaxed excess free volume (REFV) and nano-crystallites, which favor the plastic deformation in Cu47.5Zr47.5Al5 BMGs. Regulating the preparing parameters is an important solution to good plasticity in BMGs.


2016 ◽  
Vol 66 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Amit Handa ◽  
Vikas Chawla

AbstractThe present study emphasizes on joints two industrially important materials AISI 304 with AISI 1021steels, produced by friction welding have been investigated. Samples were welded under different axial pressures ranging from 75MPa to 135MPa, at constant speed of 920rpm. The tensile strength, torsional strength, impact strength and micro hardness values of the weldments were determined and evaluated. Simultaneously the fractrography of the tensile tested specimens were carried out, so as to understand the failure analysis. It was observed that improved mechanical properties were noticed at higher axial pressures. Ductile failures of weldments were also observed at 120MPa and 135MPa axial pressures during fractography analysis.


2020 ◽  
Vol 25 (2) ◽  
Author(s):  
Christian Caglioni ◽  
Felipe Mello Rigon ◽  
, Marcelo André Losekann ◽  
Luciana Cristina Soto Herek Rezende ◽  
Mychelle Vianna Pereira Companhoni ◽  
...  

ABSTRACT Aluminum alloys are not covered by their specific weight. Each class of aluminum alloy presents a set of properties that are favorable to a given function in the same product, just as the alloys may be present in the same vehicle. However, it is necessary to know the changes in the mechanical properties that occur with the union process of these aluminum alloys. The objective of this study was to evaluate the mechanical and morphological properties of alloys 5383 H34, 5754 H34 and 6005 T6 similarly welded and dissimilar by the MIG process. Six combinations of these alloys were characterized by mechanical tensile, folding and Vickers micro-hardness tests, as well as scanning electron microscopy (SEM) and optical microscopy (OM). Among the results obtained, a decrease in tensile strength was observed for all welded alloys. In addition, the microhardness was affected in the melt line, in the weld bead and in the HAZ (heat affected zone). The main causes of the reduction of the mechanical resistance of the welded alloys were the grain growth and the precipitate dissolution. The data obtained in this study contribute in a very positive way to the development and dimensioning of new projects and technologies involving aluminum alloys.


2013 ◽  
Vol 685 ◽  
pp. 259-263 ◽  
Author(s):  
K. Subbaiah ◽  
Geetha Manivasagam ◽  
B. Shanmugarajan ◽  
S.R. Koteswara Rao

Laser beam welding of aluminum alloys is expected to offer good mechanical properties of welded joints. In this experimental work reported, CO2 laser beam welding at 3.5 kW incident power was conducted autogenously on 5 mm thick 5083-H321 aluminum alloy plates at different welding speeds. The mechanical properties and microstructural characteristics of the welds are evaluated through tensile tests, micro-hardness tests, optical microscopy and scanning electron microscopy (SEM). Both yield stress and tensile strength of the laser beam welded joint at the optimum welding speed were 88 % of base metal values. Experimental results indicate that the tensile strength and hardness of laser beam welds are affected by the variation of the intermetallic compounds.


2011 ◽  
Vol 391-392 ◽  
pp. 564-568
Author(s):  
Ai Li Wei ◽  
Kun Yu Zhang ◽  
Xian Rong Li ◽  
Wei Liang

This work mainly investigated the influence of element Nd on the microstructure and mechanical properties of the Zn-25Al-5Mg-2.5Si alloys with different Nd contents. The tensile and hardness tests were carried out at room and elevated temperatures. The results show that the addition of element Nd leads to the grain refining and the formation of Al2Nd and NdZn2 phases in the microstructure, and the mechanical properties of the alloys rise at first and then drop with the increasing of Nd content. The optimization of microstructure and performance especially the tensile strength at high temperature is obtained when Nd content is 0.8 wt.%. It can result in increase of tensile strength by 48.8% and micro-hardness by 67.4% at 180。C.


2015 ◽  
Vol 1766 ◽  
pp. 45-52
Author(s):  
Raúl J. Fernández Tavitas ◽  
Rocío Saldaña Garcés ◽  
Víctor H. López Cortéz

ABSTRACTIn this paper the effect of hybrid laser arc welding on longitudinal joints for pipes of 1.27cm thick is investigated. For the investigation, an API X70 steel was welded with the HLAW process and then subjected to tensile, bending and micro hardness tests under standards for pipe manufacturing. Images of the weld seams were taken to observe the structure and size of the weld zones. Analysis was made by light microscopy to determine the phases present in the weld zones and to observe if there is a variation of grain size in the weld zones that adversely affects the mechanical properties of the API X70 steel. Results show that the mechanical properties of the joints meet the requirements for their use in pipe manufacturing; one reason is the low thickness of the weld zone that barely affects the original properties of API X70 steel. Also the presence of bainite in the microstructure of weld zones provides resistance to the joints.


2019 ◽  
Vol 1 (3) ◽  
pp. 8
Author(s):  
Anitha P ◽  
Manik ChandraMajumder ◽  
Saravanan V ◽  
Rajakumar S

In this paper, standard SS304 austenitic stainless steel and SS430 ferritic steel cylindrical rods were fabricated by friction welding process by varying the frictional pressure and forge pressure in order to understand the effect of process parameter. The tensile strength and Vickers micro hardness tests were conducted for each fabricated joint to evaluate the mechanical properties of the welded specimen. It was found that sample S5 with friction pressure of 90 MPa and forging Pressure of 120 MPa has the high tensile strength value of 637 MPa and 372HV at the interface region. A detailed microstructural analysis was performed at the interface to reveal interconnecting of dissimilar metals.


2018 ◽  
Vol 767 ◽  
pp. 343-350
Author(s):  
Mads Rostgaard Sonne ◽  
Jesper Henri Hattel

In the present work a 2D axisymmetric thermomechanical model of the direct-drive friction welding process is developed, taking the temperature dependent shear yield stress into account in the description of the heat generation, utilizing a recent thermal pseudo mechanical model originally developed for the friction stir welding (FSW) process. The model is implemented in ABAQUS/Explicit via a subroutine. The application in this case is joining of austenitic stainless steel rods with an outer diameter of 112 mm, used for manufacturing of exhaust gas valves for large two stroke marine engines. The material properties in terms of the temperature dependent flow stress curves used both in the thermal and the mechanical constitutive description are extracted from compression tests performed between 20 °C and 1200°C on a Gleeble 1500 thermomechanical simulator. Comparison between measured and simulated transient temperatures shows relatively good agreement and furthermore, the simulated deformations in terms of upsetting length and flash formation are also in good agreement with the observations from the experiment.


2005 ◽  
Vol 284-286 ◽  
pp. 693-696 ◽  
Author(s):  
Min Wang ◽  
C.L. Au ◽  
P.K. Lai ◽  
William Bonfield

For the purpose of mimicking the structure and matching mechanical properties of human cortical bone, a natural composite material, hydroxyapatite (HA) reinforced high density polyethylene (HDPE) has been developed as a bioactive, analogue material for bone replacement. This synthetic composite material is now in clinical use. To understand the deformation behaviour and determine mechanical properties of HA/HDPE composite under different loading modes and loading conditions, tensile and compression tests were performed in the current investigation. It was observed that under tension, HA/HDPE composite exhibited two types of deformation behaviour: ductile and brittle. Under compression, the composite deformed in a ductile manner and did not fracture at high compressive strains. It was found that an increase in HA content resulted in increases in Young’s modulus, compressive modulus, tensile strength and compressive yield strength of the composite. A higher strain rate led to higher modulus and strength values and lower tensile fracture strains of the composite.


Author(s):  
K. Giridharan ◽  
P. Sevvel ◽  
K. Senthilnathan ◽  
S. Muthukumaran ◽  
S. Padmanabhan

In this research article, the mechanical properties and microstructure analysis ofFriction Stir Welded (FSW) of dissimilar aluminium alloys AA8011-AA6082 were evaluated. The FSW tool with taper cylindrical shape of H13 steel was selected to fabricate the weld joints between the dissimilar alloys. In this regard, three different rotational speed tools, three welding speeds and an unvarying axial load of 7 kN are used in this investigation. The tool rotational speeds are 800 rpm, 1000 rpm and 1200 rpm. The tool travelling speeds are 25mm/min, 30 mm/min and 35 mm/min. These constraints are used to generate frictional heat and interface into the soft range where the joining process can take place between the two materials. The mechanical tests were carried out on the weld joints. Microstructure analysis, tensile and hardness tests were considered by changing the tool rotating speed, welding speed and maintaining a constant axial force during material joining process. The micro hardness of the FSW weld joints in the stir zone increased to increase the tool rotational speed as well as to maintain a low range of welding speed during material joining process. The micro hardness of the stir zone in the FSW weld joints is increased as to reduce the welding speed. It was found that the highest value of the tensile strength in the joints is made-up of using the taper-shaped tool at 800 rpm, welding speed of 35mm/min and unvarying downward force of 7kN. These identified parameters give sufficient mechanical properties and fewer defects in weld joints such as tensile strength of 68 N and micro hardness of 42 Hv. The tensile and hardness tests values are examined by the part of mechanical characterization and the values are correlated to recognize the superiority of the weld joint.


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