Tribological Behavior of Composite Electrodes for Spot Welding

2014 ◽  
Vol 656 ◽  
pp. 3-10
Author(s):  
Ionelia Voiculescu ◽  
Victor Geanta ◽  
Elena Manuela Stanciu ◽  
Mihai Vasile ◽  
Tiberiu Laurian ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Spot Welding ◽  
Mechanical Characteristics ◽  
Local Heating ◽  
Tribological Characteristics ◽  
Strengthening Effect ◽  
Composite Electrodes ◽  
Metallic Elements ◽  
Melted Zone ◽  
Resistance To Deformation

The paper presents some aspects regarding tribological characteristics of composite tops of the electrodes for spot welding. The solution aims to improve the resistance to deformation and high intensity electric current conductibility without loses and excessive local heating. The composite material was obtained by mechanical alloying process, from a mixture of tungsten carbide, chromium, CuNiAl alloy and cooper powder which has been heated in furnace at 1100°C. The embedding process aims to avoid the toxic effects of metallic elements such as Be and Zr, which are usually introduced in cupper alloys for improving the mechanical characteristics. The tribological characteristics and microhardness of the melted zone were measured in order to estimate the strengthening effect obtained by the tungsten carbide presence for different mixture recipe.

Properties and Spot Welding Performance of Copper Composite Reinforced with Recycled Tungsten Carbide

2010 ◽  
Vol 154-155 ◽  
pp. 1485-1488
Author(s):  
Zuhailawati Hussain ◽  
Indra Putra Almanar
Keyword(s):  
Electrical Conductivity ◽  
Tungsten Carbide ◽  
Spot Welding ◽  
Copper Matrix ◽  
Raw Material ◽  
Composite Electrodes ◽  
Welding Operation ◽  
Metal Metal ◽  
Copper Matrix Composite ◽  
Copper Composite

In this work, properties and spot welding performance of copper matrix composite electrode reinforced with 15 vol% tungsten carbide particulate from inexpensive raw material were investigated. Mixture of copper and recycled tungsten carbide was milled, compacted, sintered and powder forged at different pressures. Higher forging pressure resulted in higher density and electrical conductivity as it accelerates the flow of copper matrix leading to porosity elimination and improves metal-metal contact within the copper matrix by reducing porosity and oxide film. Welding operation showed that composite electrodes with higher density, electrical conductivity and hardness forms larger and stronger spot weld.

Effect of Local Heating on the Mechanical Characteristics of Repaired Automotive Panels

2019 ◽  
Vol 56 (4) ◽  
pp. 750-758
Author(s):  
Nicolae Navodariu ◽  
Mihai Branzei ◽  
Robert Ciocoiu ◽  
Ion Ciuca ◽  
Razvan Coman ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Cold Working ◽  
Local Heating ◽  
Thin Sheet ◽  
Heating Time ◽  
Steel Plates ◽  
Maximum Temperature ◽  
Material Microstructure ◽  
Technology Process ◽  
Automotive Panels

Flame straightening is a technology process used to eliminate deformations. This method relies on local heating of the material to correct geometry or damaged parts. In the local automobile services its main use is for repairs of less critical deformed components. The maximum temperature and thermal gradient, heating time, cooling rate and number of heating cycles affect the mechanical properties since local heating can alter material microstructure. The aim of this research was to determine the mechanical characteristics of thin steel plates repaired by local heating associated with plastic deformation (similar to hot working) and cold straightening (similar to local cold working) for automotive side and door panels made of structural steel. Thin sheet plates, 0.9mm thickness, were deformed by impact and repaired by local heating using the flame and induction heating then plastically deformed while hot as well as straightened without heating. The heat repaired samples were studied by light microscopy to determine microstructure change and samples were tensile tested to determine their mechanical characteristics. Local excessive grain growth generates anisotropy, the assembly behaves as a composite material with regions that show significant plastic deformations while others little or no deformations at al. Without procedures adjusted to each material repairs involving heating are to be avoided, cold working should be employed when replacement is not possible.

Tribological characteristics of WC1-x, W2C and WC tungsten carbide films

2005 ◽  
pp. 409-417 ◽  
Author(s):  
M. Gubisch ◽  
Y. Liu ◽  
S. Krischok ◽  
G. Ecke ◽  
L. Spiess ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Tribological Characteristics

Refractory Core-Shell Powders for Additive Industries

2017 ◽  
Vol 265 ◽  
pp. 529-534 ◽  
Author(s):  
Sergey P. Bogdanov ◽  
A.P. Garshin
Keyword(s):  
Thin Films ◽  
Silicon Carbide ◽  
Composite Materials ◽  
Boron Nitride ◽  
Tungsten Carbide ◽  
Mechanical Characteristics ◽  
Core Shell ◽  
Refractory Materials ◽  
Iodide Transport ◽  
Physical And Mechanical Characteristics

The finished products obtained when the surfaces of powders of refractory materials (diamond, boron nitride, silicon carbide, tungsten carbide, tungsten) were coated with thin films by the method of iodide transport are presented. The developed method enables to obtain powder composite materials of core-shell type that have surface thickness varying in the range from 1 nm to several micrometers. From the powders modified by the films of metals and thier compounds composite materials were developed, their physical and mechanical characteristics were studied. The characteristics turned out to be substantially higher in comparison to materials sintered from the same powders but without coating. The probable fields of use of the composites in question were determined.

Researches about Mechanical Characteristics of some Steels Resistance Spot Welded

2013 ◽  
Vol 371 ◽  
pp. 265-269
Author(s):  
Marius Ioan Chirileanu ◽  
Diana Antonia Gheorghiu
Keyword(s):  
Spot Welding ◽  
Mechanical Characteristics ◽  
Welded Joint ◽  
Variable Parameter ◽  
Welding Current ◽  
Shear Resistance ◽  
Hardness Profile ◽  
Tensile Shear ◽  
Resistance Spot ◽  
Steel Grades

This work studies the influence of resistance spot welding (RSW) process upon the mechanic characteristics of three steel grades: S235JR, galvanized S235JR and austenitic stainless grade 304L. The variable parameter was the welding current. Constant parameters were the pressure (6 bars) and the welding time (5 cycles). Micro hardness and tensile-shear resistance tests were done. Welded joint hardness profile reveal a relative softer nuclei surrounded by the hardest zone and a progressive decrease throughout the heat affected zone (HAZ) to the unaffected material. The shear resistance depends upon the welding intensity as well as metal grade.

scholarly journals MULTI-OBJECTIVE OPTIMIZATION OF THE RESISTANCE SPOT-WELDING PROCESS PARAMETERS FOR THE WELDING OF DUAL-PHASE STEEL DP500

2021 ◽  
Vol 55 (2) ◽  
pp. 201-206
Author(s):  
Aleksija Djuric ◽  
Dragan Milčić ◽  
Damjan Klobčar ◽  
Biljana Marković
Keyword(s):  
Automotive Industry ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Dual Phase Steel ◽  
Mechanical Characteristics ◽  
Welding Process ◽  
Dual Phase ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Resistance Spot

Resistance spot welding (RSW) is still the most used form of welding in the automotive industry, primarily for welding steel. One of the advanced steels used in the automotive industry is dual-phase steel, so it is important to properly select the welding parameter for these steels. Therefore, this paper presents multi-objective optimization in the RSW welding process of DP 500 steel. The paper considers three different mechanical characteristics i.e., the failure load (F), failure displacement (l) and weld nugget diameter (D), as all these welding characteristics play significant roles in evaluating the quality of spot welding. The results show that the welding current is the most influential parameter with respect to the mechanical characteristics. The effect of welding time on the weld quality is the least significant. The optimal parameters for welding DP 500 steel obtained in this paper are weld current 8 kA, electrode force 4.91 kN and weld time 400 ms.

scholarly journals Characterization of Sintered Aluminium Reinforced with Ultrafine Tungsten Carbide Particles

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1416
Author(s):  
Omid Emadinia ◽  
Maria Teresa Vieira ◽  
Manuel Fernando Vieira
Keyword(s):  
Tungsten Carbide ◽  
Ultrafine Particles ◽  
High Speed ◽  
High Vacuum ◽  
Microstructural Characterization ◽  
Mechanical Tests ◽  
Crystallographic Analysis ◽  
Phase Identification ◽  
Strengthening Effect ◽  
Electron Backscattered Diffraction

The strengthening effect on aluminium (Al) by ultrafine particles of tungsten carbide (WC) after compacting and sintering was evaluated. The Al-1 vol.% WC mixture was prepared through a high-speed stirring technique, called assisted sonication. In this study, the effects of compacting, sintering temperature and holding time were evaluated by composite microstructural characterization and by mechanical tests. The characterizations involved electron dispersive spectroscopy and X-ray diffraction techniques for phase identification; electron backscattered diffraction for crystallographic analysis; backscattered electrons and secondary electrons imaging for failure and wear studies. In all composites, hardness was determined; for the hardest composite, the tensile strength, flexural strength and ball scattering wear resistance were also evaluated. The Al-1 vol.% WC composite produced by assisted sonication, densified by cold compacting at 152 MPa and sintered at 640 °C for 2 h at 5 × 10−4 Pa (high vacuum) exhibited the highest hardness, associated with an acceptable ductile behavior. This strengthening was associated with the formation of Al12W and grain refinement.

scholarly journals Fabrication of Zinc–Tungsten Carbide Nanocomposite Using Cold Compaction Followed by Melting

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Injoo Hwang ◽  
Zeyi Guan ◽  
Xiaochun Li
Keyword(s):  
Tungsten Carbide ◽  
Melting Process ◽  
Strengthening Effect ◽  
Nanoparticle Dispersion ◽  
Compression Tests ◽  
Cold Compaction ◽  
New Class ◽  
Good Biocompatibility ◽  
Micropillar Compression ◽  
Mechanical Strengths

Zinc (Zn) is an important material for numerous applications since it has pre-eminent ductility and high ultimate tensile strain, as well high corrosion resistivity and good biocompatibility. However, since Zn suffers from low mechanical strengths, most of the applications would use Zn as a coating or alloying element. In this study, a new class of Zn-based material with a significantly enhanced mechanical property is developed. The zinc-10 vol % tungsten carbide (Zn-10WC) nanocomposite was fabricated by cold compaction followed by a melting process. The Zn-10WC nanocomposites offer a uniform nanoparticle dispersion with little agglomeration, exhibiting significantly enhanced mechanical properties by micropillar compression tests and microwire tensile testing. The nanocomposites offer an over 200% and 180% increase in yield strength and ultimate tensile strength (UTS), respectively. The strengthening effect could be attributed to Orowan strengthening and grain refinement induced by nanoparticles.

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