scholarly journals Producing wear-resistant materials by SHS-casting with the application of centrifugal forces

2019 ◽  
Vol 64 (3) ◽  
pp. 275-285
Author(s):  
V. V. Klubovich ◽  
M. M. Kulak ◽  
V. G. Samolyotov ◽  
B. B. Khina
Keyword(s):  
Uniform Distribution ◽  
Measurement Instrument ◽  
High Wear Resistance ◽  
Centrifugal Forces ◽  
Wear Resistant ◽  
Soft Matrix ◽  
Reactive Iron ◽  
Centrifugal Shs ◽  
Strengthening Particles ◽  
Shs Casting

The paper is devoted to the problem of producing hard, wear-resistant materials by SHS-casting using centrifugal forces. We have developed a device for centrifugal SHS casting and initial compositions of the reactive iron-base charge. A technology for producing coatings, materials and final products with a non-uniform distribution of strengthening particles over the specimen volume has been developed and tested in industrial conditions. The microstructure and phase composition of the synthesized material with a non-uniform distribution of reinforcing particles is studied. The synthesized material implements the Charpy principle: dispersed hard carbide particles are distributed in a relatively soft matrix, which ensures high wear resistance. By means of SHS casting, billets were obtained for producing a measurement instrument, namely a plug-type gauge, which successfully passed industrial tests at OJSC “VIZAS”. The tests shown that the hardness of all synthesized samples was in the range from 63 to 68 HRC and the number of measurements per 1 micron of wear on a diameter of15 mm was 2500 to 2700. Hence, the developed method made it possible to significantly increase the service life of the measuring tool: by a factor of 1.5 to 2.

Structure and properties of NiAl-Cr(Co,Hf) alloys prepared by centrifugal SHS casting. Part 1 – Room temperature investigations

2017 ◽  
Vol 690 ◽  
pp. 463-472 ◽  
Author(s):  
A.A. Zaitsev ◽  
Zh.A. Sentyurina ◽  
E.A. Levashov ◽  
Yu.S. Pogozhev ◽  
V.N. Sanin ◽  
...  
Keyword(s):  
Room Temperature ◽  
Structure And Properties ◽  
Centrifugal Shs ◽  
Shs Casting

The Effect of Microstructure on Properties of Fe-Cr-C-Nb/Ti Hardfacing Alloy

2011 ◽  
Vol 279 ◽  
pp. 126-131 ◽  
Author(s):  
Wen Bo Tang ◽  
Yun Gang Guo ◽  
Hon Grui Wang
Keyword(s):  
Wear Resistance ◽  
Alloy System ◽  
Energy Dispersive Spectrum ◽  
High Wear Resistance ◽  
Low Carbon ◽  
Shielded Metal Arc Welding ◽  
Wear Resistant ◽  
Hardfacing Alloy ◽  
The Matrix ◽  
Carbon Martensite

Hardfacing is one of the most useful and economical ways to improve the performance of components submitted to severe wear conditions. In this paper, a new kind of alloy called Fe-Cr-C-Nb/Ti alloy system for wear resistant successfully with the shielded metal arc welding (SMAW) method has been studied. The microstructure and wear resistant of hardfacing alloys reinforced with primary carbides were compared in this study. Meanwhile, the average hardness, the abrasion weight loss and microstructure of deposited metal were systematically studied by optical microscopy, scanning electronic microscopy and energy dispersive spectrum analysis. The results showed that the microstructure of the best optimizing hardfacing layer was the mixed martensite and little retained austenite, and NbC/TiC particles distributing dispersively in the matrix. The amount of low-carbon martensite and high-carbon martensite was identical. The alloy system showed high wear resistance due to the formation of dispersed MC type carbides and good toughness due to the exist of low carbon martensite in the matrix. The hardfacing alloy reinforced with complex carbides was also investigated, the microstructure was analyzed and its hardness and wear resistance were evaluated. In conclusion, the distribution, the chemical composition and the amount of the carbides, as well as the matrix microstructure are all factors to influence the crack resistance, hardness and wear resistance of the hardfacing alloys.

Nanomechanical Properties of Amorphous Carbon and Carbon Nitride Thin Films Prepared by Shielded Arc Ion Plating

1999 ◽  
Vol 593 ◽  
Author(s):  
N. Tajima ◽  
H. Saze ◽  
H. Sugimura ◽  
O. Takai
Keyword(s):  
Thin Films ◽  
Wear Resistance ◽  
Amorphous Carbon ◽  
Carbon Nitride ◽  
Arc Discharge ◽  
High Wear Resistance ◽  
Substrate Bias Voltage ◽  
Wear Resistant ◽  
Arc Ion Plating ◽  
Ion Plating

ABSTRACTHydrogen free amorphous carbon (a-C) and carbon nitride (a-C:N) were synthesized by means of shielded arc ion plating in which a shielding plate was inserted between a target and a substrate in order to reduce macroparticle deposition onto the substrate. Using a graphite target as a cathode, thin films of a-C and a-C:N were prepared in an arc discharge plasma of argon or nitrogen gas, respectively, at a pressure of 1 Pa. Based on nanoindentation, mechanical properties of these films were studied in relation to substrate bias voltage (Vs). The a-C films prepared at Vs ranging from -50 to -200 V consisted of diamond-like phase and showed hardness higher than 20 GPa with its maximum of 35 GPa at Vs = -100 V. However, hardness of the films deposited at Vs < 300 V was less than 7 GPa indicating that the films were converted to graphite-like phase due to excessive ion impact in Ar plasma. Wear resistance of the a-C films was closely related to their hardness. Namely, a harder a-C film was more wear resistant. On the contrary, hardness of the a-C:N films was less dependent on Vs. It remained in the range of 10 to 15 GPa and was much lower than the maximum hardness of the a-C films. Nevertheless, the wear resistance of the a-C:N films was comparable to or much better than the a-C films. In particular, the a-C:N film prepared at Vs = -300 V was so wear resistant that the film showed no apparent wear when rubbed with a diamond tip less than 100 nm in tip-diameter at a contact force of 20μN. The presence of β-C3N4like phase characterized by a N1 s XPS peak at 400.5 eV has found to be crucial for high wear resistance of the a-C:N films

Nanomechanical Properties of Amorphous Carbon and Carbon Nitride Thin Films Prepared by Shielded Arc Ion Plating

1999 ◽  
Vol 594 ◽  
Author(s):  
N. Tajima ◽  
H. Saze ◽  
H. Sugimura ◽  
O. Takai
Keyword(s):  
Thin Films ◽  
Wear Resistance ◽  
Amorphous Carbon ◽  
Carbon Nitride ◽  
Arc Discharge ◽  
High Wear Resistance ◽  
Substrate Bias Voltage ◽  
Wear Resistant ◽  
Arc Ion Plating ◽  
Ion Plating

AbstractHydrogen free amorphous carbon (a-C) and carbon nitride (a-C:N) were synthesized by means of shielded arc ion plating in which a shielding plate was inserted between a target and a substrate in order to reduce macroparticle deposition onto the substrate. Using a graphite target as a cathode, thin films of a-C and a-C:N were prepared in an arc discharge plasma of argon or nitrogen gas, respectively, at a pressure of 1 Pa. Based on nanoindentation, mechanical properties of these films were studied in relation to substrate bias voltage (VS). The a-C films prepared at VS ranging from −50 to −200 V consisted of diamond-like phase and showed hardness higher than 20 GPa with its maximum of 35 GPa at Vs = −100 V. However, hardness of the films deposited at VS < -300 V was less than 7 GPa indicating that the films were converted to graphite-like phase due to excessive ion impact in Ar plasma. Wear resistance of the a-C films was closely related to their hardness. Namely, a harder a-C film was more wear resistant. On the contrary, hardness of the a-C:N films was less dependent on VS. It remained in the range of 10 to 15 GPa and was much lower than the maximum hardness of the a-C films. Nevertheless, the wear resistance of the a-C:N films was comparable to or much better than the a-C films. In particular, the a-C:N film prepared at VS = -300 V was so wear resistant that the film showed no apparent wear when rubbed with a diamond tip less than 100 nm in tip-diameter at a contact force of 20 μN. The presence of β-C3N4 like phase characterized by a Nls XPS peak at 400.5 eV has found to be crucial for high wear resistance of the a-C:N films.

Team-Related Knowledge Measurement Instrument

2007 ◽  
Author(s):  
Tristan E. Johnson ◽  
Youngmin Lee ◽  
Miyoung Lee ◽  
Debra L. O'Connor ◽  
Mohammed K. Khalil ◽  
...  
Keyword(s):  
Measurement Instrument ◽  
Knowledge Measurement

Levels taxation countries the EU and Ukraine’s

2019 ◽  
pp. 131-160
Author(s):  
Helena Borzenko ◽  
Tamara Panfilova ◽  
Mikhail Litvin
Keyword(s):  
European Union ◽  
Uniform Distribution ◽  
Tax Burden ◽  
Tax System ◽  
Tax Legislation ◽  
Improvement Process ◽  
Tax Systems ◽  
Historical Comparative ◽  
Different Levels ◽  
The Eu

Purpose articles rassm and experience and benefits systems taxation countries European Union, manifestation iti the main limitations domestic taxlegislation and wired STI their comparisons. In general iti ways the provisiontax reporting countries Eurozone in the appropriate organs, dove STI need theintroduction Ukraine electronic methods receiving and processing such reports.define iti key directions reforming domestic tax legislation. Methodology research is to use aggregate methods: dialectical, statistical, historical, comparative. Scientific novelty is to are provided recommendations for improvement ofefficiency systems taxation of our states in international ratings characterizingtax institutions country. Therefore, despite some problems in legislation heldcomparative study systems taxation EU and Ukraine. Conclucions Coming fromof this, the main directions reforming tax systems Ukraine, in our opinion,today should become: improvement process administration, reduce scales evasiontaxes, provision more uniform distribution tax burden between taxpayers, themaximum cooperation tax bodies different levels as well adjustment systemselectronic interactions tax authorities and payers, tax system must contain ascan less unfounded benefits, consistent with the general by politics pricing.

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