THE EFFECT OF CARBIDES PRECIPITATION ON THE SLIDING WEAR CHARACTERISTICS ACCORDING TO HEAT TREATMENT CONDITIONS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4426-4431 ◽  
Author(s):  
CHANG-MIN SUH ◽  
GYE-WON CHOI ◽  
KYUNG-RYUL KIM ◽  
MOON-SIK HAN

This study investigated the effect of carbide precipitation hardening of heat-treated SK5M steel on the sliding wear resistance. The cold rolled carbon steel strip samples (J, G, and S-type) were oil quenched after tempering for optimal durations. The wear resistance was evaluated using a pin-on-disk wear test with an alumina counterface against different samples at various loads and distances with a constant running speed. The size and distribution of the precipitated carbides were observed using an image analyzer at various heat treatments. The heat-treated samples presented more dense carbide distribution in an area fraction and the decreased size of carbides. It is confirmed that the wear rate is minimum at an optimized austenitizing temperature of around 800°C. The specific wear rate indicates that the S-type sample has high wear resistance compared to that of J-Type. This is understood by stable wear behavior of S-type sample containing evenly distributed carbide precipitation.

2017 ◽  
Vol 740 ◽  
pp. 9-16
Author(s):  
Ahmed Sahib Mahdi ◽  
Mohammad Sukri Mustapa ◽  
Mahmod Abd Hakim Mohamad ◽  
Abdul Latif M. Tobi ◽  
Muhammad Irfan Ab Kadir ◽  
...  

The micro-hardness and compression of recycling aluminum alloy AA6061 were investigated as a function of the different microstructure and constituent powder metallurgy method. Five specimens were selected to investigate the compression strength and microhardness. The first, as fabricated specimen (as compacted), the second was as heat treated by quenching and aging process. Three specimens were mixed with Graphite particles as a reinforcement material. Compression strength values were tested for the specimens as fabricated and heat treated which were 195 and 300 MPa, respectively. The improvement ratio was 52% for the specimen as heat treated. On the other hand, high wear resistance was given by the specimen as heat treated, whereas, the lower wear strength was at the specimen mixed with 4.5% Graphite. These results were attributed to that the wear resistance related to the microhardness value.


2015 ◽  
Vol 830-831 ◽  
pp. 358-361 ◽  
Author(s):  
D.G. Sondur ◽  
D.M. Goudar ◽  
D.G. Mallapur ◽  
G.B. Rudrakshi

In the present investigation, microstructural characteristics and dry sliding wear behaviour of T6 heat treated conventionally cast Al-25Mg2Si-2Cu alloy have been discussed. The as cast alloy was subjected to solutionizing at 500°C for 5h and isothermal aging treatment at 190°C for different aging times. The micro structural characterization was studied using Scanning Electron Microscope with EDS analysis. The microstructure of as cast alloy consists of intermetallics of coarse block like sharp edged β-(Mg2Si), θ-(Al2Cu) and Q-(Al-Mg-Cu-Si) in the form of Chinese scripts and needles distributed randomly in the Al-matrix. The microstructure of heat treated alloy shows spheroidization of β phase and fine precipitation of θ-(Al2Cu) and Q phases. The dry sliding wear test was carried out using pin-on-disc machine. Age hardened alloy exhibits high wear resistance and minimum coefficient of friction over the entire range of applied loads and sliding velocities. Furthermore, high wear resistance was observed in the under aged condition compared to over ageing conditions.


Author(s):  
Akshay Shinde

Abstract: To improve the wear resistance of the hybrid powder coating, TiO2 nanoparticles was hot mixed to form a homogenous mixture with the powder in the range varying wt. dry sliding wear test conducted to determine the wear resistance. The experiments were design according to Taguchi L9 array to find the optimum nanoparticles content required to minimize the wear rate of the coating. ANOVA was used to determine the effect of the parameters on wear rate. It showed that reinforcement has the maximum contribution on the wear rate of the coating as compared to load and frequency. From the graph of means optimum parametric values was obtained at 2 % wt of reinforcement, 2 N load and 2 Hz frequency. The wear rate decrease with the increase in reinforcement. Keywords: Taguchi Method, Tribometer, Hybrid powder, TiO2, Wear Rate.


Author(s):  
Gobinda C. Saha ◽  
Tarek A. ben Mahmud ◽  
Tahir I. Khan

Grain size, their distribution and geometry are important to study the dislocation behavior and grain boundary sliding of ceramic reinforced metallic composite materials. Grain size reduction has been shown to lead to significant improvements of the wear resistance in nanostructured materials. As the grain size decreases from polycrystalline to nanocrystalline range, abrasive wear resistance increases considerably from the increased hardness and volume loss following Archard’s law of wear. Further, the heat treatment effect on the content of the metallic binder in a ceramic-metallic (cermet) material is thought to increase the hardness with decreasing crystalline size, thereby improving the sliding wear behavior of materials. In this study, the high velocity oxy-fuel (HVOF) thermal spraying of nanostructured WC-17Co coatings with engineered ‘duplex outer coating’ is conducted. The microhardness and sliding wear studies of the coatings and their heat-treated counterparts are performed. The nanostructured coatings showed a significant increase in the microhardness and wear resistance when compared with those of the conventional microstructured coatings of the same composition. It is believed that the improved performance is related with the work hardening as well as dispersion hardening of the nanostructured grains in the deposited coatings.


2007 ◽  
Vol 561-565 ◽  
pp. 773-776
Author(s):  
Toshio Tanimoto

The wear behavior of CFRP laminates with nano-particles dispersed surfaces of Al2O3 or carbon has been investigated and compared with that of conventional CFRP which is without particles dispersed surfaces. As a result of comparison, it is shown that the CFRP laminate with Al2O3 nano-particles dispersed surfaces inherently had low coefficient of friction and high sliding wear resistance. The measured value of specific wear rate was 3.5x10-7mm3/Nm, independently of sliding time. The wear behavior of CFRP laminates with carbon nano-particles dispersed surfaces has been more effectively improved. The measured specific wear rate of this material was in the range of 10- 7mm3/Nm in spite of comparatively small amount of nano-particles dispersion, which is relatively good as tribomaterial. For the successful application of this method, it is essential to explore the optimum amount of Al2O3 or carbon nano-particles to be dispersed onto prepreg surfaces. The deflocculation of the agglomerated particles and their homogeneous dispersion and good impregnation are the key points in this technology.


2019 ◽  
Vol 26 (10) ◽  
pp. 1950074
Author(s):  
ZHI-YUAN ZHU ◽  
JIA-HUAN CHEN ◽  
YUAN-FEI CAI ◽  
JIAN-QIANG LI

This study explored the friction and wear behavior of a Ni-based exhaust valve at high temperatures. Nickel-based superalloy was used with two types of processing states: the original forged sample and the sample under the standard T1 heat treatment. At room temperature and a loading force of 10[Formula: see text]N, the average friction coefficient of the T1 heat-treated specimen is 0.61, which was lower than that of the forged sample (0.78). The wear rate of this specimen was also lower than that of the forged sample at the same temperature and loading force. Thus, T1 heat treatment can significantly improve the wear resistance of the alloy because of [Formula: see text] phase and carbides. The wear rate was the minimum at 550∘C and increased again at 750∘C dominated by the formation and flake-off of the oxide film.


2017 ◽  
Vol 898 ◽  
pp. 355-360
Author(s):  
Hang Li ◽  
Shi Chao Liu ◽  
Jin Chuan Jie ◽  
Ting Ju Li

Special brasses containing Mn and Si possess high wear resistance due to the dispersion of hard Mn5Si3 particles. The effect of precipitation hardening on the wear resistance of a Cu–30Zn–3Al–3Mn–0.7Si based brass alloy was investigated. Dry sliding wear test was conducted using a block-on-ring configuration. The results indicated that finely, nanoscale Mn5Si3 particles precipitated from the matrix after annealing at 800 °C for 4 h, resulting in the increase of hardness from 240 to 278 HV. Both the wear loss and friction coefficient decreased, indicating the improvement of the wear resistance. From the examination of the worn surfaces, adhesive and abrasive wear were found to be the major wear forms. The adhesion and abrasion decreased after the precipitation-hardening treatment.


2015 ◽  
Vol 788 ◽  
pp. 143-150
Author(s):  
Alexandra Gontarenko ◽  
Kai Möhwald ◽  
Todd Alexander Deißer ◽  
Hans Jurgen Maier

Thermal spraying is one of the most efficient methods to deposit hard wear resistant coatings. The coatings deposited by High-Velocity-Oxygen-Fuel spraying (HVOF) are characterized by high wear resistance and outstanding tribological characteristics. One of the most challenging tasks for tribologists is to develop surface treatments that allow for both operating the component without lubricants and at the same time minimize wear. WC-based cermets are a group of thermally sprayed coatings known to have high wear resistance under sliding friction conditions. An experimental study on the dry sliding wear behavior of WCCo HVOF-sprayed coating deposited onto a steel substrate is presented in the current paper. A pin-on-disc tribometer was used to carry out the wear tests.


2012 ◽  
Vol 433-440 ◽  
pp. 572-577
Author(s):  
Hua Chen ◽  
Hai Ying Sun ◽  
Zhan Kui Zhao ◽  
Zhi Long Chai

Fe-Ni-Mo-C-Cr system powder metallurgy in the as-sintered was investigated on pin-on-rolling wear tester for their dry sliding wear behavior. The morphology of worn surfaces and wear mechanism were analysed by SEM. Results show the hot-forging deformation quenching and tempered considerably decreased the porosity and improved wear resistance, and compare with quenching microstructure, tempered microstructure has high wear resistance and match of strength-toughness. Fe-2.0Ni-0.4Mo-0.5C-0.6Cr alloy presented best wear characteristics. SEM observations of the worn surface revealed microploughing and plastic deformation and crack were the basic dry sliding wear morphology,and oxidative wear and delamination wear are dominant wear mechanism.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5932
Author(s):  
Min Wei ◽  
Qiang Wan ◽  
Shanjun Li ◽  
Liang Meng ◽  
Daocheng Cao ◽  
...  

The abrasion failure is the key factor for prolonging the service life and energy saving of furrow openers. The hardness enhancement was reported to be an effective strategy to increase the wear resistance against the soil abrasion. D517 coatings were deposited on Q235 steel by electric spark to improve the wear-resistant property with an affordable cost for farmers. The wear behavior of the coatings was characterized in a pin on disk friction equipment and a homemade soil abrasion simulation system. The soil adhesion, which is highly related to energy consumption, was also evaluated. Results showed that D517 coatings revealed dendrite structure with some randomly distributed carbides. The electric current exerted a great influence on the microstructure, hardness, friction coefficient, and soil wear rate. The wear rate of samples deposited with 80 A and 90 A reduced to 79% and 84%, respectively, as compared with the normalized heat-treated 65 Mn steel after 6 h in soil. This work provides a promising solution to increase the wear resistance of furrow openers. It needs to be noted that the coating would increase the soil adhesion of the opener, which needs to be further explored to decrease the energy consumption.


Sign in / Sign up

Export Citation Format

Share Document