Surface Mechanical Properties of Tool Steel on the Addition of Carbon Nanotubes with the Process of Flame Spray Tungsten Carbide Coatings

2020 ◽  
Vol 1000 ◽  
pp. 238-247
Author(s):  
Sunoto Mudiantoro ◽  
M. Gerry ◽  
Winarto Winarto ◽  
Muhammad Anis ◽  
M. Kemal ◽  
...  

Tungsten Carbide (WC) hard coating is widely used to coat the surface of the steel tools which provide tribological properties. In this paper, 0.25 wt% & 0.35 wt% of Carbon Nanotubes (CNT) were mixed with tungsten carbide (WC) powders as the feedstock powders. Method of solution dispersion in ethanol media using an ultrasonic device was used for coating the surface of WC powders with CNT powder. The mixed powders were then used as the feedstock powder to coat onto the surface of tool steel using the flame spraying process. The coated surface microstructures were observed under a scanning electron microscope (SEM), x-ray diffraction (XRD), and the energy dispersive spectroscopy (EDS) was used for the phase characterization and identification. The wear rate of coated steels was determined using the Ogoshi machine, and the Vickers hardness method used to measure their microhardness. The effects of CNT on the microstructure of the coated material and the surface mechanical properties were investigated. The results showed that the mixture powder preparation using an ultrasonic method in SDS solution and the ball-milling process was suitable to disperse the CNT on the surface of WC feed powders due to produce an adequate relationship between CNT' and WC powders increasing the surface mechanical properties of coatings. The wear resistance of the coated material produce using the mixture of WC powder with 0.35 wt% CNT increased around 50% higher than the WC coated steel without CNT addition. Also, the hardness of coating reinforced CNT increased significantly compared with the hardness of WC coated and the steel substrates. Microhardness value from the base metal to the WC-CNT coated steel increased from 550 HV to 1717 HV and also the wear rate from the base metal to the WC-CNT coated steel decreased from 0.86 mm3/min to 0.017 mm3/min. These results indicate that CNT is an excellent alternative to improve the surface mechanical properties of WC coatings.

2003 ◽  
Vol 788 ◽  
Author(s):  
G. L. Tan ◽  
X. J. Wu ◽  
Z. Q. Li

ABSTRACTA novel approach for the synthesis of carbon nanotubes strengthened nanostructured tungsten carbide was investigated, in which nanophase tungsten powders are carburized by C2H2 instead of CO and a fraction of decomposed carbons were in situ converted to nanotubes. In this way, the composite powders of nanocrystal WC-Co and carbon nanotubes have been in situ prepared. The composite WC-Co powders were then hot pressed into bulk alloy which shows a exceptionally high microhardness up to 3307 kg/mm2. It is proposed that carbon nanotubes with extra high Young's modulus (1.8 Tpa) play both roles on strengthening the composite matrix and prohibiting growth of WC grains, which results in the great improvement of the mechanical properties of the samples. The average grain size of the prepared WC-Co hard alloys was estimated to be less than 100 nm. The effect of hot press temperature on the mechanical properties of the prepared alloys was also studied in detail.


2014 ◽  
Vol 493 ◽  
pp. 666-671
Author(s):  
Viktor Malau ◽  
Subagyo Subagyo ◽  
Supriyanto

The objective of this research is to characterize the effects of heat treatment such as quenching, tempering and TiN coating on mechanical and physical properties of duylos 2510 steel. These mechanical properties include wear rate, hardness, impact toughness, whereas physical properties are microstructures. Duylos 2510 steel is a cold work tool steel and has chemical composition (wt %) of 1C; 0,6 Cr; 0,1 V; 1 Mn; 0,25 Si and 0,6 W.Quenching process has been conducted by heating the specimens on austenite temperature of 800 °C with the soaking time of 30 minutes and then cooling these specimens in oil medium. Tempering process was done at temperatures of 100, 200, 300, 400, 500 dan 600 °C with holding time of 2 hours.TiN coating has been deposited on substrates by sputtering technique of Physical Vapor Deposition at temperatures of 100, 150, 200 and 250 °C with sputtering time of 45 minutes. The mechanical and physical properties have been characterized by wear test, Vickers micro hardness test, Charpy impact test, and metallography test. This research was performed at room temperature and the major parameters of this research were tempering and sputtering temperatures.The results show that tempering temperature variations give significant modification of mechanical properties. In general, the Vickers micro-hardness decreases if tempering temperatures of the specimen increase. The highest Vickers micro-hardness of TiN coatings is 290 HV0,01 for the specimen having sputtering temperature of 200 °C. Wear rate and impact energy increase if tempering temperatures increase. The results also show that the Vickers micro-hardness of coated specimens is higher than the micro Vickers hardness of non-coated specimens


2012 ◽  
Vol 2 (6) ◽  
pp. 166-168 ◽  
Author(s):  
Dr.T.Ch.Madhavi Dr.T.Ch.Madhavi ◽  
◽  
Pavithra.P Pavithra.P ◽  
Sushmita Baban Singh Sushmita Baban Singh ◽  
S.B.Vamsi Raj S.B.Vamsi Raj ◽  
...  

2015 ◽  
Vol 57 (5) ◽  
pp. 447-457 ◽  
Author(s):  
Hassan S. Hedia ◽  
Saad M. Aldousari ◽  
Ahmed K. Abdellatif ◽  
Gamal S. Abdelhaffez

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 923
Author(s):  
Kun Huang ◽  
Ji Yao

The potential application field of single-walled carbon nanotubes (SWCNTs) is immense, due to their remarkable mechanical and electrical properties. However, their mechanical properties under combined physical fields have not attracted researchers’ attention. For the first time, the present paper proposes beam theory to model SWCNTs’ mechanical properties under combined temperature and electrostatic fields. Unlike the classical Bernoulli–Euler beam model, this new model has independent extensional stiffness and bending stiffness. Static bending, buckling, and nonlinear vibrations are investigated through the classical beam model and the new model. The results show that the classical beam model significantly underestimates the influence of temperature and electrostatic fields on the mechanical properties of SWCNTs because the model overestimates the bending stiffness. The results also suggest that it may be necessary to re-examine the accuracy of the classical beam model of SWCNTs.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 875
Author(s):  
Hao Tian ◽  
Jianchao He ◽  
Jinbao Hou ◽  
Yanlong Lv

TiB crystal whiskers (TiBw) can be synthesized in situ in Ti alloy matrix through powder metallurgy for the preparation of a new type of ceramic fiber-reinforced Ti matrix composite (TMC) TiBw/Ti-6Al-4V. In the TiBw/Ti-6Al-4V TMC, the reinforced phase/matrix interface is clean and has superior comprehensive mechanical properties, but its machinability is degraded. Hence, the bonding of reliable materials is important. To further optimize the TiBw/Ti-6Al-4V brazing technology and determine the relationship between the microstructure and tensile property of the brazed joint, results demonstrate that the elements of brazing filler metal are under sufficient and uniform diffusion, the microstructure is the typical Widmanstätten structure, and fine granular compounds in β phase are observed. The average tensile strength of the brazing specimen is 998 MPa under room temperature, which is 97.3% of that of the base metal. During the high-temperature (400 °C) tensile process, a fracture occurred at the base metal of the highest tensile test specimen with strength reaching 689 MPa, and the tensile fracture involved a combination of intergranular and transgranular modes at both room temperature and 400 °C. The fracture surface has dimples, secondary cracks are generated by the fracture of TiB whiskers, and large holes form when whole TiB whiskers are removed. The proposed algorithm provides evidence for promoting the application of TiBw/Ti-6Al-4V TMCs in practical production.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3140
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Rafał Kozera ◽  
Paweł Durałek ◽  
Łukasz Sarniak ◽  
...  

The main aim of this work was the investigation of the possibility of replacing the heavy metallic meshes applied onto the composite structure in airplanes for lightning strike protection with a thin film of Tuball single-wall carbon nanotubes in the form of ultra-light, conductive paper. The Tuball paper studied contained 75 wt% or 90 wt% of carbon nanotubes and was applied on the top of carbon fibre reinforced polymer before fabrication of flat panels. First, the electrical conductivity, impact resistance and thermo-mechanical properties of modified laminates were measured and compared with the reference values. Then, flat panels with selected Tuball paper, expanded copper foil and reference panels were fabricated for lightning strike tests. The effectiveness of lightning strike protection was evaluated by using the ultrasonic phased-array technique. It was found that the introduction of Tuball paper on the laminates surface improved both the surface and the volume electrical conductivity by 8800% and 300%, respectively. The impact resistance was tested in two directions, perpendicular and parallel to the carbon fibres, and the values increased by 9.8% and 44%, respectively. The dynamic thermo-mechanical analysis showed higher stiffness and a slight increase in glass transition temperature of the modified laminates. Ultrasonic investigation after lightning strike tests showed that the effectiveness of Tuball paper is comparable to expanded copper foil.


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