scholarly journals Effect on Microstructure and Performance of B4C Content in B4C/Cu Composite

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1250
Author(s):  
Dayu Shu ◽  
Xiuqing Li ◽  
Qingxia Yang
Keyword(s):  
Wear Resistance ◽  
Discharge Plasma ◽  
Pure Copper ◽  
Mechanical Mixing ◽  
Composite Surface ◽  
Plasma Sintering ◽  
And Performance ◽  
Pure Cu ◽  
Boron Carbide B4c ◽  
Microstructure And Performance

In this paper, boron carbide (B4C) ceramics were added to a copper (Cu) base, to improve the mechanical properties and wear resistance of pure copper. The B4C/Cu composites with different B4C contents, were obtained by mechanical mixing and discharge plasma sintering methods. Scanning electron microscopy (SEM), energy spectrum analysis (EDS), and electron probe microanalysis (EPMA) were used, to observe and analyze the microstructures of the B4C/Cu composites. The influences of the B4C content on the hardness, density, conductivity, and wear resistance were also studied. The experimental results show that B4C has an important effect on Cu. With increasing B4C content, both the density and conductivity of the B4C/Cu composites gradually decrease. The hardness of the Cu-15 wt.% B4C composite has the highest value, 86 HBW (Brinell hardness tungsten carbide ball indenter), which is 79.2% higher than that of pure copper. However, when the B4C amount increases to 20 wt.%, the hardness decreases due to the metallic connection being weakened in the material. The Cu-15 wt.% B4C composite has the lowest volume loss, indicating that it has the best wear resistance. Analyses of worn B4C/Cu composite surfaces suggest that deep and narrow grooves, as well as sharp ridges, appear on the worn pure Cu surface, but on the worn Cu-15 wt.% B4C composite surface, the furrows become shallow and few. In particular, ridge formation cannot be found on the worn Cu-15 wt.% B4C composite surface, which represents the enhancement in wear resistance.

Enhancement of Wear Resistance of Copper With Tungsten Addition (≤20 wt %) by Powder Metallurgy Route

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Poulami Maji ◽  
R. K. Dube ◽  
Bikramjit Basu
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Electrical Contacts ◽  
Operating Conditions ◽  
Fretting Wear ◽  
Wear Loss ◽  
Composite Surface ◽  
The Coefficient Of Friction ◽  
Improved Performance ◽  
Pure Cu

Copper–tungsten composite materials are developed for applications such as electrical contacts, resistance electrodes, and contact tips in welding guns as well as for components requiring higher wear resistance. In addition to the aspect of improved performance, it is scientifically interesting to assess the tribological properties, and therefore the objectives of the present work include, to determine the role of W additions in improving the fretting wear resistance of Cu for electrical applications, to determine the optimum concentration for W additions, and to identify the mechanisms responsible for fretting wear improvements. In addressing these issues, a planned set of fretting wear tests were conducted on powder metallurgically processed Cu–W composites (maximum W content of 20 wt %) against steel counterbody under varying load (up to 10 N) for 10,000 cycles. It has been observed that at lower loads of 2 N, the coefficient of friction (COF) recorded was ∼0.9 for the Cu–20 wt % W/steel, whereas it was ∼0.85 for a pure Cu/steel couple. Under similar operating conditions with the increase in load, the COF decreases to 0.5 at 10 N load, irrespective of the composition of the Cu–W composite. Furthermore, the incorporation of 5 wt % W has reduced the volumetric wear loss by 4–6 folds in comparison to unreinforced Cu. The addition of even higher percentage of W has led to increase its wear resistance by ∼10 folds. Under the investigated conditions, the wear rate systematically decreases with the increase in load for all the tested Cu–W composites. Based on the topographical observation of worn surfaces, it is observed that wear mechanisms for the Cu and Cu–W composites are tribochemical wear, adhesive wear, and abrasive wear. The incorporation of harder W particles (5 wt % or more) help in abrading the steel ball and in forming a dense tribolayer of FexOy, which effectively reduces wear rate and hence, increases wear resistance of the Cu–W composite surface in reference to unreinforced Cu.

scholarly journals Feasibility of Cobalt-Free Nanostructured WC Cutting Inserts for Machining of a TiC/Fe Composite

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3432
Author(s):  
Edwin Gevorkyan ◽  
Mirosław Rucki ◽  
Tadeusz Sałaciński ◽  
Zbigniew Siemiątkowski ◽  
Volodymyr Nerubatskyi ◽  
...  
Keyword(s):  
Cubic Boron Nitride ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Machined Surface ◽  
Powder Consolidation ◽  
Plasma Sintering ◽  
Cutting Inserts ◽  
Spark Plasma ◽  
And Performance ◽  
Nanostructured Tungsten Carbide

The paper presents results of investigations on the binderless nanostructured tungsten carbide (WC) cutting tools fabrication and performance. The scientific novelty includes the description of some regularities of the powder consolidation under electric current and the subsequent possibility to utilize them for practical use in the fabrication of cutting tools. The sintering process of WC nanopowder was performed with the electroconsolidation method, which is a modification of spark plasma sintering (SPS). Its advantages include low temperatures and short sintering time which allows retaining nanosize grains of ca. 70 nm, close to the original particle size of the starting powder. In respect to the application of the cutting tools, pure WC nanostructure resulted in a smaller cutting edge radius providing a higher quality of TiC/Fe machined surface. In the range of cutting speeds, vc = 15–40 m/min the durability of the inserts was 75% of that achieved by cubic boron nitride ones, and more than two times better than that of WC-Co cutting tools. In additional tests of machining 13CrMo4 material at an elevated cutting speed of vc = 100 m/min, binderless nWC inserts worked almost three times longer than WC-Co composites.

Selecting the Parameters for Brazing 08 Steel with Pure Copper Solder Paste

2010 ◽  
Vol 426-427 ◽  
pp. 432-435
Author(s):  
De Gong Chang ◽  
J. Zhang ◽  
M.L. Lv
Keyword(s):  
Carbon Steel ◽  
Filler Metal ◽  
Pure Copper ◽  
Low Carbon Steel ◽  
Solder Paste ◽  
Low Carbon ◽  
Technical Parameters ◽  
And Performance ◽  
Steel Joints ◽  
The Ideal

The larger variation of the construction and performance of the low-carbon steel joints was caused by the high temperature of the puddle welding of the joint. Therefore, the braze welding rather than the puddle welding was applied to the welding production of low-carbon steel. The 08 steel parts were joined in a furnace using pure copper solder paste as brazing filler metal. According to the obtained results, the ideal technical parameters are as follow: brazing temperature: 1100-1150°C; holding time: 5-10min; joint clearance: 0.03-0.05mm.

Examination of the material properties and performance of thin-diamond film cutting tool inserts produced by arc-jet and hot filament chemical vapor deposition

1996 ◽  
Vol 11 (7) ◽  
pp. 1765-1775 ◽  
Author(s):  
James M. Olson ◽  
Michael J. Dawes
Keyword(s):  
Wear Resistance ◽  
Chemical Vapor Deposition ◽  
Diamond Film ◽  
Vapor Deposition ◽  
Cutting Tool ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
And Performance ◽  
Hot Filament

Thin diamond film coated WC-Co cutting tool inserts were produced using arc-jet and hot-filament chemical vapor deposition. The diamond films were characterized using SEM, XRD, and Raman spectroscopy to examine crystal structure, fracture mode, thickness, crystalline orientation, diamond quality, and residual stress. The performance of the tools was evaluated by comparing the wear resistance of the materials to brazed polycrystalline diamond-tipped cutting tool inserts (PCD) while machining A390 aluminum (18% silicon). Results from the experiments carried out in this study suggest that the wear resistance of the thin diamond films is primarily related to the grain boundary strength, crystal orientation, and the density of microdefects in the diamond film.

Modification of microstructure and performance via doping Ti in W–1TiC fine-grained alloy

2021 ◽  
Vol 825 ◽  
pp. 141918
Author(s):  
Ziwei Zhang ◽  
Siqi Zhao ◽  
Yongqi Lv ◽  
Hongbo Zhang ◽  
Zhenwei Wang ◽  
...  
Keyword(s):  
Fine Grained ◽  
And Performance ◽  
Microstructure And Performance
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