scholarly journals Characterization of ultrafine-grained copper joints acquired by rotary friction welding

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
M. Ciemiorek ◽  
Ł. Morawiński ◽  
C. Jasiński ◽  
M. Orłowska ◽  
T. Chmielewski ◽  
...  
Keyword(s):  
Grain Size ◽  
Heat Input ◽  
Friction Welding ◽  
Uniform Elongation ◽  
Weld Zone ◽  
Base Material ◽  
Processing Parameters ◽  
High Energy ◽  
Ultrafine Grained ◽  
Rotary Friction Welding

AbstractCopper rods with ultrafine-grained microstructure, obtained by multi-turn ECAP processing, were subjected to Direct Drive Rotary Friction Welding using various processing parameters, such as rotational speed and pressure, which resulted in different energy and heat input. Even though friction welding is a high energy process, by a proper selection of processing parameters it was possible to maintain grain size at around 0.7 µm in the weld zone and preserve the UFG microstructure. These microstructural features translated into mechanical properties: the YS for those specimens was around 330 MPa. Processing parameters that resulted in a larger heat input caused an increase in grain size to around 2 µm; this, however, increased ductility and led to a uniform elongation exceeding 5%. Corrosion resistance in the stir zone increased, as was evident in the higher open circuit potential and higher corrosion potential in comparison with base material; the observed differences were about 50 mV. These changes can be explained by the higher fraction of HAGBs in the SZ.

scholarly journals Relationship between diameter of base material and heat input in friction welding of 6061 aluminum alloy.

2002 ◽  
Vol 52 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Takeshi SAWAI ◽  
Koichi OGAWA ◽  
Hiroshi YAMAGUCHI ◽  
Hiizu OCHI ◽  
Yoshiaki YAMAMOTO ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Heat Input ◽  
Friction Welding ◽  
Base Material ◽  
6061 Aluminum Alloy

scholarly journals A Study on Rotary Friction Welding of Titanium Alloy (Ti6Al4V)

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ho Thi My Nu ◽  
Truyen The Le ◽  
Luu Phuong Minh ◽  
Nguyen Huu Loc
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloys ◽  
Friction Welding ◽  
Base Material ◽  
Welding Process ◽  
High Strength ◽  
Fusion Welding ◽  
Experimental Results ◽  
Thermomechanical Model ◽  
Rotary Friction Welding

The selection of high-strength titanium alloys has an important role in increasing the performance of aerospace structures. Fabricated structures have a specific role in reducing the cost of these structures. However, conventional fusion welding of high-strength titanium alloys is generally conducive to poor mechanical properties. Friction welding is a potential method for intensifying the mechanical properties of suitable geometry components. In this paper, the rotary friction welding (RFW) method is used to study the feasibility of producing similar metal joints of high-strength titanium alloys. To predict the upset and temperature and identify the safe and suitable range of parameters, a thermomechanical model was developed. The upset predicted by the finite element simulations was compared with the upset obtained by the experimental results. The numerical results are consistent with the experimental results. Particularly, high upset rates due to generated power density and forging pressure overload that occurred during the welding process were investigated. The performances of the welded joints are evaluated by conducting microstructure studies and Vickers hardness at the joints. The titanium rotary friction welds achieve a higher tensile strength than the base material.

Appropriate Conditions for Preparation of Nanosized WO3 through High-Energy-Milling

2011 ◽  
Vol 194-196 ◽  
pp. 665-668
Author(s):  
Chun Huan Chen ◽  
Rui Ming Ren
Keyword(s):  
Grain Size ◽  
Milling Time ◽  
Rotation Speed ◽  
Processing Parameters ◽  
High Energy ◽  
Charge Ratio ◽  
Activation Process ◽  
X Ray Diffraction ◽  
High Energy Milling ◽  
Transmission Electron

In order to synthesize WC-Co nanopowders through an integrated mechanical and thermal activation process, WO3-Co2O3-C nanopowders need to be obtained first. It is critical how to obtain the WO3-Co2O3-C nanopowders efficiently. The effect of processing parameters on the grain size during high-energy-milling of WO3-Co2O3-C mixed powders was studied via X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the grain size of reactants can be effectively decreased with increasing the milling time, rotation speed, and charge ratio. After a certain time milling, both WO3 and C powders achieve nano-level in grain size and mixed homogeneously. The appropriate milling parameters for fabricating nanosized WO3+C+Co2O3 powders are suggested to be 4 to 8 hours of milling time, 400 RPM of rotation speed, and 40:1 to 60:1 of charge ratio.

scholarly journals Solid-state welding of ultrafine grained copper rods

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Łukasz Morawiński ◽  
Cezary Jasiński ◽  
Marta Ciemiorek ◽  
Tomasz Chmielewski ◽  
Lech Olejnik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Contact Surface ◽  
Base Material ◽  
Low Energy ◽  
Direct Drive ◽  
Ultrafine Grained ◽  
Rotary Friction Welding ◽  
Machine Parts ◽  
Welding Pressure

AbstractThe article focuses on the Direct Drive Rotary Friction Welding of ultrafine-grained copper rods, which feature increased mechanical properties and good electrical properties, yet are limited in size. The use of UFG metals is often limited by the too small dimensions of semi-finished elements produced by SPD methods. Therefore, the production of finished machine parts from UFG metals is currently economically unjustified. Dismissal of dimensional limitations can be done by introducing joining to technological processes. The proposed joining method does not lead to a melting of the material in the joining zone or excessive degradation of the UFG microstructure. To obtain the best results, the research used the method of low-energy welding of two kinds of specimens: with a flat or a conical contact surface. In the article, the authors present, by means of metallographic microsections and microhardness measurements, the influence of rotational speed, welding pressure and conical shape contact surface on the quality of the obtained joints. The conducted research made it possible to obtain good quality joints whose microhardness is reduced only by about 10% in comparison with the base material and the tensile strength dropped from only 397–358 MPa.

scholarly journals Effect of Rotary Friction Welding Parameters on the Mechanical Behavior ABS/PE Polymers

2018 ◽  
Vol 7 (4) ◽  
pp. 104
Author(s):  
Gailan I. Hassan ◽  
Younis Kh. Khdir
Keyword(s):  
Tensile Strength ◽  
Friction Welding ◽  
Mechanical Energy ◽  
Acrylonitrile Butadiene Styrene ◽  
Processing Parameters ◽  
Welding Parameters ◽  
Chemical Formula ◽  
Dissimilar Joints ◽  
Rotary Friction Welding ◽  
Butadiene Styrene

This study deals with the Rotary Friction Welding, (RFW) as a variation of friction welding in which the energy required to make the weld is supplied primarily by the stored rotational kinetic energy of the welding machine. The mechanical energy generated in overcoming friction is continuously transformed into heat. In most circumstances the thermal energy generated is regarded as undesirable, but under controlled conditions it can be used to join materials, as in the case of rotary friction welding. In this paper, similar and dissimilar joints of Acrylonitrile butadiene styrene (ABS) (chemical formula (C8H8)x· (C4H6)y· (C3H3N)z) and Polyethylene (PE) or polyethene or poly(methylene)) are studied. The effects of different rotational rates, plunge depths, and traverse speeds on the microstructure and tensile strength of joints were investigated. Some defects such as pores and cracks were found at inappropriate processing parameters. The tensile test was carried out as the mechanical properties of joints. Different significant parameters were discussed. The maximal and minimal tensile strength indicated and evaluated.

Effect of Welding Heat Input on Grain Size and Microstructure of 316L Stainless Steel Welded Joint

2013 ◽  
Vol 331 ◽  
pp. 578-582 ◽  
Author(s):  
Li Chan Li ◽  
Meng Yu Chai ◽  
Yong Quan Li ◽  
Wen Jie Bai ◽  
Quan Duan
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Heat Input ◽  
316L Stainless Steel ◽  
Weld Zone ◽  
Welding Process ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Average Grain Size ◽  
Arc Welding Process

Influences of heat input on the microstructure and grain size of shielded metal arc welded 316L stainless steel joints were studied. Three heat input combinations were selected from the operating window of the shielded metal arc welding process and welded joints made using these combinations were subjected to microstructural evaluations so as to analyze the effect of thermal arc energy on the microstructure and grain size of these joints. The results of this investigation indicate that the microstructure of the weld zone and the fusion zone are austenite and a small amount of ferrite while the microstructure of the heat affected zone (HAZ) are austenite and a small amount of MC type carbides, and it can be seen that the amount of ferrite in the weld zone decreases with heat input. For the joints investigated in this study, the average grain size in the HAZ increases with heat input.

scholarly journals Production of Ultrafine Grained Hardmetals by Electrical Resistance Sintering

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 159 ◽  
Author(s):  
Jesús Cintas ◽  
Raquel Astacio ◽  
Francisco Cuevas ◽  
Juan Montes ◽  
Thomas Weissgaerber ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Electrical Resistance ◽  
Processing Parameters ◽  
Medium Frequency ◽  
Main Achievement ◽  
Processing Times ◽  
Ultrafine Grained ◽  
Protective Atmospheres ◽  
Optimal Values

In this work, powders of cemented ultrafine WC-6 wt.% Co were consolidated. The feasibility of the medium frequency electrical resistance sintering (MF-ERS) technique were studied to prevent WC grain growth during consolidation. Porosity and hardness were measured at different zones of the MF-ERS compacts. The compacts showed a slight inhomogeneity in their properties across their section, but it was controlled by choosing suitable values of the processing parameters. The optimal values for the material studied were current intensities between 7 and 8 kA and sintering times between 600 and 800 ms. The main achievement using this consolidation method was that sintered compacts essentially maintained the initial WC grain size. This was attained to processing times of less than 2 s, and without the need for using protective atmospheres.

scholarly journals Effect of faying surfaces and characterization of aluminium AA6063-steel AISI304L Dissimilar joints fabricated by friction welding with Hemispherical Bowl, and Threaded Faying Surfaces

2021 ◽  
Author(s):  
Senthil Murugan Subramanian ◽  
Sathiya Paulraj ◽  
Noorul Haq Abdul Haq
Keyword(s):  
Impact Toughness ◽  
Friction Welding ◽  
Weld Zone ◽  
Welding Process ◽  
Weld Interface ◽  
Dissimilar Joints ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
Faying Surface ◽  
Rotary Friction Welding

Abstract This work describes the effect of newly introduced faying surfaces on the microstructure and the mechanical properties of dissimilar weld joints of AA6063 and AISI304L alloys that fabricated through the rotary friction welding process (RFW). The experiments were done as six different experimental methods (‘A’ to ‘F’) at 1300 rpm rotation, 18 MPa friction pressure (FP), 24 MPa upset pressure (UP) and 5 sec friction time (FT) with the faying surfaces of hemispherical bowl and thread of 1 mm pitch on the weld specimens. The fabricated joints and the weld zones were characterized by macro and micro-study, Energy Dispersive X-ray Spectroscopy (EDS) spectrums, tensile properties, Vickers microhardness, impact toughness and fractography. The results showed that these faying surface modifications strengthen the bonding between the weld specimens and influences the performance of the joints. The hemispherical bowl showed better results than the threaded surfaces. Axial shortenings were within the acceptable limit in the range of 20–27 mm. Macro and microstructural studies showed the defect-free weld joints and the strong bonding between AA6063 and AISI304L alloys. The hemispherical faying surface on AISI304L alloy formed a U-shaped weld interface (WI) in the dissimilar joints. EDS proved the formation of the Fe-Al intermetallic and the element ‘O’ at weld zone. The joint efficiency for all the methods was around ≥ 100%. Maximum tensile strength was recorded as 238 MPa for method ‘F’. The threaded surface showed good hardness property nearby WI and method ‘A’ yielded maximum impact toughness for the joint.

Research on Intergranular Corrosion Behavior of Welded Joints of Nuclear Grade Stainless Steel

2014 ◽  
Vol 809-810 ◽  
pp. 390-394
Author(s):  
Meng Yu Chai ◽  
Can Liang ◽  
Dong Dong Wang ◽  
Quan Duan ◽  
Zao Xiao Zhang
Keyword(s):  
Stainless Steel ◽  
Welded Joints ◽  
Heat Input ◽  
Intergranular Corrosion ◽  
Weld Zone ◽  
Base Material ◽  
Delta Ferrite ◽  
316Ln Stainless Steel ◽  
Welding Heat Input ◽  
Micro Structures

The intergranular corrosion (IGC) behaviors of welded joints of 316LN stainless steel with different welding heat input were investigated in this study. The boiling nitric acid method was chosen to provide the IGC environment. The corrosion rates of different specimens were studied and the micro-structures of each zone (base material, heat affected zone and weld zone) were analyzed in detail. The results show that welding heat input affects IGC resistance remarkably and low welding heat input can reduce the IGC tendency. The IGC test can be divided into three stages, i.e. the initial corrosion stage, stable corrosion stage and rapid corrosion stage. The IGC resistance of WZ for 316LN stainless steel is better than that of BM and HAZ due to the beneficial role of delta ferrite.

Linear Friction Welding of a Forged Near-α Titanium Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 211-216 ◽  
Author(s):  
E. Dalgaard ◽  
Priti Wanjara ◽  
Javad Gholipour ◽  
John J. Jonas
Keyword(s):  
Titanium Alloy ◽  
Friction Welding ◽  
Creep Resistance ◽  
Electron Backscatter Diffraction ◽  
Weld Zone ◽  
Base Material ◽  
High Tech ◽  
Linear Friction Welding ◽  
Linear Friction ◽  
Backscatter Diffraction

IMI834 (Ti-5.8Al-4Sn-3.5Zr-0.7Nb-0.5Mo-0.35Si) is a high-tech near-α titanium alloy with improved creep resistance and mechanical property retention at temperatures up to 600°C [1]. It is used in the aerospace industry for compressor disks and blades due to its excellent balance between creep resistance and fatigue strength [2]. The linear friction welding (LFW) behaviour of IMI834 displaying an initial bimodal α+β microstructure was investigated using varying axial pressures during welding. Electron backscatter diffraction (EBSD) was used to characterize the texture and phase fraction of the welded IMI834 samples in the weld zone (WZ) and thermomechanically affected zones (TMAZ) in relation to the base material. Based on microhardness evaluation of the weldments, the WZ was determined to be slightly harder than the base material.

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