scholarly journals The Kinetics and Dry-Sliding Wear Properties of Boronized Gray Cast Iron

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Dong Mu ◽  
Bao-luo Shen

Some properties of boride formed on gray cast iron (GCI) have been investigated. GCI was boronized by powder-pack method using Commercial LSB-II powders at 1123, 1173, and 1223 K for 2, 4, 6, and 8 h, respectively. Scanning electron microscopy showed that boride formed on the surface of boronized GCI had tooth-shaped morphology. The hardness of boride formed on surfaces of GCI ranged from 1619 to 1343 HV0.025, and quenched and tempered GCI ranged from 400 to 610 HV0.025. The boride formed in the coating layer confirmed by X-ray diffraction analysis was Fe2B single phase. Depending on boronizing time and temperature, the thickness of coating layers on boronized GCI ranged from 26 to 105 μm. The activation energy was 209 kJ/mol for boronized GCI. Moreover, the possibility of predicting the iso-thickness of boride layers variation was studied. Dry-sliding wear tests showed that the wear resistance of boronized sample was greater than that of quenched and tempered sample.

2009 ◽  
Vol 1 (3) ◽  
pp. 516-527 ◽  
Author(s):  
S. N. Pandya ◽  
S. K. Nath ◽  
G. P. Chaudhary

The surface of gray cast iron has been modified by Tungsten Inert Gas (TIG) process. Welding current of magnitude 25, 35, and 45 amperes have been used to melt the surface of gray cast iron. Microstructural characterization, hardness measurement and dry sliding wear tests have been performed on these modified surfaces. It has been observed that increase in welding current caused the microstructure of grey cast iron to be gradually refined. Graphite flakes segregated between interdendritic regions in the as-received grey cast iron have been completely replaced by a uniform distribution of finer graphite flakes in the matrix. Hardness has been found to increase with increase in welding current. Wear resistance of the gray cast iron also increased with increase in the welding current reaching maximum value for 45 amperes. The increased hardness and wear resistance of these modified surfaces have been explained on the basis of microstructural changes occurring at the surfaces of gray cast iron.  Keywords: Gray cast iron; Surface modification; TIG process; Dry sliding wear.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.vli3.2577    J. Sci. Res. 1 (3), 516-527 (2009)


2016 ◽  
Vol 32 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Qi Sui ◽  
Hong Zhou ◽  
Haifeng Zhang ◽  
Li Feng ◽  
Lin Yang ◽  
...  

Abstract


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mokgadi Nomsa Mokgalaka ◽  
Sisa Lesley Pityana ◽  
Patricia Abimbola Idowu Popoola ◽  
Tebogo Mathebula

The NiTi intermetallic possesses a number of good properties, such as high wear, oxidation, and corrosion resistance. This paper focuses on the deposition of NiTi intermetallic coatings on Ti6Al4V substrate by laser melting of Ti and Ni elemental powder mixtures. The effect of varying the Ti content in the NiTi composition on the microstructure and wear properties of the coatings was investigated. The microstructure of the NiTi intermetallic coatings were characterized by the scanning electron microscope (SEM) equipped with Energy Dispersive Spectroscope (EDS). The wear properties of the coatings were performed under accelerated dry sliding wear tests. The results obtained from the SEM/EDS analysis; show that the coatings consist of Ni and Ti elements from the feedstock, and the NiTi, NiTi2and NiTi3, intermetallic phases. Dry sliding wear analysis revealed that there is correlation between the hardness and the wear rate. The coatings displayed significant improvement in wear resistance up to 80% compared to the substrate.


2009 ◽  
Vol 83-86 ◽  
pp. 1035-1042
Author(s):  
Ghasem Azimi ◽  
Morteza Shamanian

In the present study, the surface of St52 steel was alloyed with preplaced powders Fe-Cr-C and Fe-Cr-Si-C by using a tungsten-inert gas (TIG) heat source. Then microstructure of the alloyed surfaces was investigated. Following the surface alloying, conventional characterization techniques, such as optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction were employed to study the microstructure of the alloyed surface. Microhardness measurements were performed across the alloyed zone. The tribological behavior of the coatings was compared in room temperature dry sliding wear tests. It was found that the as-deposited coatings consisted of higher volume fraction of carbides (Cr7C3). No crack formation was found on the coatings. As a result, TIG arc heat source can be used effectively for performing surface alloying on St52 steel with a preplaced powder in order to improve its surface wear resistance.


2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540024
Author(s):  
Pengfei Yan ◽  
Deping Wang ◽  
Biao Yan

In this research, Cu-9Pb high leaded bronze were prepared by spray forming. The microstructure and wear properties of this bronze alloy were systematically investigated. The results show that although the hardness of spray formed alloy was not increased comparing with the cast alloy, it still presented a lower wear rate and a lower friction coefficient in dry sliding wear tests as shallower grooves and more lubricating films were observed in the spray formed bronze (BSF14). Spray forming also refined the lead phase microstructure of Cu-9Pb bronze and improved its wear properties.


2012 ◽  
Vol 445 ◽  
pp. 673-678
Author(s):  
Bijan Abbasi Khazaei

In this research wear mechanism of ADI under different intensity of loading with different hardness have been investigated. To study of wear behavior, a series of austempered specimens with optimum mechanical properties were used for wear tests. Dry sliding wear tests were carried out in pin-on-ring wear tester machine at speed of 0.5 ms-1 and loaded with normal loads of 100,200,300 and 400 N. Scanning electron microscopy for microstructure and wear surface analysis was used. To determine the austenite volume fraction and the percentage of carbon content in austenite, X-ray diffraction analysis was used. Results show that the role of retained austenite at wear properties of ADI is dependent on loading intensity and austenite carbon content.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3400
Author(s):  
Yuliia Chabak ◽  
Vasily Efremenko ◽  
Miroslav Džupon ◽  
Kazumichi Shimizu ◽  
Victor Fedun ◽  
...  

The structural and tribological properties of a protective high-chromium coating synthesized on gray cast iron by air pulse-plasma treatments were investigated. The coating was fabricated in an electrothermal axial plasma accelerator equipped with an expandable cathode made of white cast iron (2.3 wt.% C–27.4 wt.% Cr–3.1 wt.% Mn). Optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction analysis, microhardness measurements, and tribological tests were conducted for coating characterizations. It was found that after ten plasma pulses (under a discharge voltage of 4 kV) and post-plasma heat treatment (two hours of holding at 950 °C and oil-quenching), a coating (thickness = 210–250 µm) consisting of 48 vol.% Cr-rich carbides (M7C3, M3C), 48 vol.% martensite, and 4 vol.% retained austenite was formed. The microhardness of the coating ranged between 980 and 1180 HV. The above processes caused a gradient in alloying elements in the coating and the substrate due to the counter diffusion of C, Cr, and Mn atoms during post-plasma heat treatments and led to the formation of a transitional layer and different structural zones in near-surface layers of cast iron. As compared to gray cast iron (non-heat-treated and heat-treated), the coating had 3.0–3.2 times higher abrasive wear resistance and 1.2–1208.8 times higher dry-sliding wear resistance (depending on the counter-body material). The coating manifested a tendency of solidification cracking caused by tensile stress due to the formation of a mostly austenitic structure with a lower specific volume. Cracks facilitated abrasive wear and promoted surface spalling under dry-sliding against the diamond cone.


2021 ◽  
Vol 36 (6) ◽  
pp. 903-910
Author(s):  
Yihong Zhao ◽  
Qianyu Chen ◽  
Zhiwei Zheng ◽  
Pei Cao ◽  
Ziyu Gong ◽  
...  

Alloy Digest ◽  
2021 ◽  
Vol 70 (3) ◽  

Abstract ISO 185/JL/275 is an intermediate-tensile-strength gray cast iron that has a pearlitic matrix and a tensile strength of 275–375 MPa (40–54 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. Compared with the lower strength gray cast iron grades, ISO 185/JL/275 contains lower carbon and silicon contents, while still maintaining good thermal conductivity and damping capacity. Owing to its higher tensile strength and hardness, it exhibits superior wear properties. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on casting and heat treating. Filing Code: CI-79. Producer or source: International Organization for Standardization.


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