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 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.

Assessment of Weld Heat-Affected Zones in a Reactor Vessel Material

1978 ◽  
Vol 100 (3) ◽  
pp. 267-271 ◽  
Author(s):  
T. U. Marston ◽  
W. Server
Keyword(s):  
Mechanical Properties ◽  
Base Material ◽  
Charpy Impact ◽  
Dynamic Fracture Toughness ◽  
Reactor Vessel ◽  
Heavy Section ◽  
Vessel Material ◽  
Submerged Arc ◽  
Weld Heat

The mechanical properties of weld heat-affected zones (HAZ’s) associated with the heavy section, nuclear quality weldments are evaluated and found to be superior to those of the parent base material. The nil ductility transition temperature (NDTT), Charpy impact and static and dynamic fracture toughness properties of a HAZ associated with a submerged arc weld and one associated with a manual metal arc weld are directly compared with those of the parent base material. It is concluded that the stigma normally associated with HAZ is not justified for this grade and quality of material and weld procedure.

The Effect of Radial-Shear Rolling on the Microstructure and Mechanical Properties of Technical Titanium

2020 ◽  
Vol 299 ◽  
pp. 565-570
Author(s):  
A. B. Naizabekov ◽  
Sergey N. Lezhnev ◽  
Alexandr S. Arbuz
Keyword(s):  
Mechanical Properties ◽  
Pure Titanium ◽  
High Strength ◽  
Grain Structure ◽  
Work Piece ◽  
Ultrafine Grained ◽  
Alloying Additives ◽  
Peripheral Areas ◽  
Radial Shear Rolling

Improving the quality of hardware through the improvement of the microstructure is one of the main trends of modern metallurgy. This approach allows us to achieve special properties without the expense of expensive alloying additives. The basic idea is to grind the grain structure of the material to a size less than 1 μm. At the specified grain sizes, the hardening properties begin to manifest with a relatively small loss of plasticity. In this case, one can speak of ultrafine-grained (UFG) materials. This direction is especially important for areas of science and technology, where there are very strict requirements for the size and weight of parts with their high strength. These are aerospace engineering and medicine (implantology and orthopedics). Therefore, it makes sense to conduct research primarily on relevant materials. Titanium is known for its biological inertness, therefore it is the basis for prosthetics. In this work, the experiments on technically pure titanium using a technology close to industrial implementation, were performed. An experiment, in which a lengthy number billet at a temperature of 500 °C rolled from a diameter of 30 mm to a diameter of 15 mm in the mill SVP-08, was conducted. After that, the billet was cooled with water, and samples for studying the microstructure and samples for studying the mechanical properties, were prepared. Analysis of the microstructure showed the presence of an equiaxial ultrafine-grained structure in the peripheral areas of the work-piece and the presence of an elongated fibrous texture in the axial zone. The strength of the work-piece has increased by more than 1.5 times, while the plasticity has decreased not so much.

Experimental Analysis and Numerical Modelling of Interphase Interfaces of New Environmental Low-Energy Composites

2015 ◽  
Vol 732 ◽  
pp. 95-98 ◽  
Author(s):  
Michal Petrů ◽  
Ondřej Novák ◽  
Petr Lepšík ◽  
Darina Myšáková
Keyword(s):  
Mechanical Properties ◽  
Maximum Level ◽  
Fiber Composites ◽  
Low Energy ◽  
Specific Strength ◽  
Micro Level ◽  
Composite Properties ◽  
Specific Orientation ◽  
Properties Of Composites

Suitable mechanical properties of composites are very important for light low energy constructions. Their specific properties can offer high specific strength, but current composite properties are not at maximum level, and therefore the efforts of development on further improving are focused. Properties of composites depend not only on character of a matrix and reinforcement, but also on properties of an Interphase between these components. Experimental and numerical analysis dealing with the mechanical properties at the micro level for new types of energy-efficient fiber composites with reduced environmental impact has been compiled. For numerical analyses a finite element method (FEM) was used. Analyses were focused on the cohesion and stress at the interface of the system fiber-matrix-core. From the results can be seen that the specific orientation of the reinforcement relative to the direction of applied force significantly affects the resulting elastic modulus. When investigating the delamination of the layers, the influence of the fiber orientation of the reinforcement is evident. Also quality of the interface has a crucial influence.

Peculiarities of Quality Ensuring in Parts from Ti-Based Alloy VT6 with Ultrafine-Grained Structure

2016 ◽  
Vol 684 ◽  
pp. 440-444
Author(s):  
Eduard Vilardovich Safin ◽  
Anatoliy Mikhailovich Smyslov
Keyword(s):  
Surface Hardening ◽  
High Load ◽  
Ultrafine Grained Structure ◽  
Technological Factors ◽  
Grain Sizes ◽  
Ultrafine Grained ◽  
Average Grain Size ◽  
Machine Parts ◽  
Directed Change

The work analyzes application perspectives of Ti-based alloy VT6 (Ti-6Al-4V) with an ultrafine-grained structure with different grain sizes as structural material to produce high-load machine parts. The paper considers technological factors for ensuring quality of parts with account of assumed conditions of their exploitation, differently directed change of mechanical properties with reduction of an average grain size and choice of surface hardening technique.

scholarly journals Study on the Effect of Energy-Input on the Joint Mechanical Properties of Rotary Friction-Welding

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 908 ◽  
Author(s):  
Guilong Wang ◽  
Jinglong Li ◽  
Weilong Wang ◽  
Jiangtao Xiong ◽  
Fusheng Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Welding ◽  
Energy Input ◽  
304 Stainless Steel ◽  
Welding Parameters ◽  
Optimal Energy ◽  
Rotary Friction Welding ◽  
Wide Range ◽  
Welding Pressure

The objective of the present study is to investigate the effect of energy-input on the mechanical properties of a 304 stainless-steel joint welded by continuous-drive rotary friction-welding (RFW). RFW experiments were conducted over a wide range of welding parameters (welding pressure: 25–200 MPa, rotation speed: 500–2300 rpm, welding time: 4–20 s, and forging pressure: 100–200 MPa). The results show that the energy-input has a significant effect on the tensile strength of RFW joints. With the increase of energy-input, the tensile strength rapidly increases until reaching the maximum value and then slightly decreases. An empirical model for energy-input was established based on RFW experiments that cover a wide range of welding parameters. The accuracy of the model was verified by extra RFW experiments. In addition, the model for optimal energy-input of different forging pressures was obtained. To verify the accuracy of the model, the optimal energy-input of a 170 MPa forging pressure was calculated. Three RFW experiments in which energy-input was equal to the calculated value were made. The joints’ tensile strength coefficients were 90%, 93%, and 96% respectively, which proved that the model is accurate.

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.

Electrical Damage Due to Low Energy Plasma Processing of GaAs Structures

1991 ◽  
Vol 223 ◽  
Author(s):  
Hans P. Zappe ◽  
Gudrun Kaufel
Keyword(s):  
Chemical Processes ◽  
Low Energy ◽  
Electrical Behavior ◽  
Rapid Thermal Anneal ◽  
High Temperature Anneal ◽  
Significant Damage ◽  
Low Energies ◽  
Long Time ◽  
Physical Plasma

ABSTRACTThe effect of numerous plasma reative ion etch and physical milling processes on the electrical behavior of GaAs bulk substrates has been investigated by means of electric microwave absorption. It was seen that plasma treatments at quite low energies may significantly affect the electrical quality of the etched semiconductor. Predominantly physical plasma etchants (Ar) were seen to create significant damage at very low energies. Chemical processes (involving Cl or F), while somewhat less pernicious, also gave rise to electrical substrate damage, the effect greater for hydrogenic ambients. Whereas rapid thermal anneal treatments tend to worsen the electrical integrity, some substrates respond positively to long-time high temperature anneal steps.

Pengaruh Tekanan dan Penggunaan Conplast terhadap Sifat Mekanik Eternit dari Abu Cangkang Sawit

2016 ◽  
Vol 8 (15) ◽  
pp. 47-54
Author(s):  
Haspiadi Haspiadi
Keyword(s):  
Mechanical Properties ◽  
Oil Palm ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Density Values ◽  
Test Result

The purpose of this research is to know the influence of pressure and use of conplast against mechanical properties which are a Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) of plasterboard. The study is done because still low quality of plasterboard made from a mixture of ashes of oil-palm shell especially of the mechanical properties compared to the controls. The method of this reserach used variation of printed pressure and the addition of conplast. Test result is obtained that the highest value of Modulus of Elasticity (MOE) 90875.94 Kg/cm2, Modulus of Rupture (MOR) 61.16 Kg/cm2 and density values in generally good printed at the pressure 60 g/cm3 and the addition of conplast 25% as well as the composition of the ash of palm shell oil 40%: limestone 40%: cement 15%: fiber 5% and 300 mL of water. ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh tekanan dan penggunaan conplast terhadap sifat mekanik yaitu kuat lentur dan keteguhan patah eternit berbahan dasar abu cangkang sawit. Penelitian ini dilakukan karena masi rendahnya mutu eternit berbahan campuran abu cangkang sawit dari bolier khususnya sifat mekanik dibandingkan dengan kontrol. Metode penelitian yang digunakan adalah dengan variasi tekanan cetak dan penambahan conplast. Hasil uji diperoleh bahwa kuat lentur tertinggi sebesar 90875,94 Kg/cm2 dan keteguhan patah sebesar 61,16 Kg/cm2, yang dicetak pada tekanan 60 g/cm3 dan penambahan conplast 25% dengan komposisi  abu cangkang sawit 40 %: kapur 40 % : semen 15 %: serat 5 % dan air 300 mL.Kata Kunci :  Abu cangkang sawit, conplast, kuat lentur, keteguhan patah.

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