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1.
Dawei Yi Jiandong Xing Shengqiang Ma Hanguang Fu Wei Chen Yefei Li Jingbo Yan Jianjun Zhang Zhuxin Liu Jing Zhu 《Tribology Letters》2011,42(1):67-77
This study investigates the effect of semi-solid processing on the microstructures, mechanical properties of low carbon Fe–B
cast alloy. The as-cast microstructure of Fe–B cast alloy consists of the eutectic boride, pearlite, and ferrite. Compared
with the coarse eutectic borides in the ordinary alloy, the eutectic boride structures in the semi-solid alloy are greatly
refined. Moreover, the boride area fraction, Rockwell hardness, impact toughness, etc., before and after heat treatment under
different casting methods are also investigated systemically. The wear behaviors of low carbon Fe–B cast alloy are studied
by three-body abrasive wear tester. The wear weight loss of semi-solid Fe–B cast alloy is lower than that of the ordinary
Fe–B cast alloy because of the lower average boride area for semi-solid specimen. Meanwhile, the wear mechanism of the low
carbon Fe–B cast alloy under different casting process is depicted and analyzed by using the physical models. 相似文献
2.
This study investigates the effect of titanium and nitrogen elements on the microstructures and wear behaviors of medium carbon Fe–B cast alloy. The as-cast microstructures of Fe–B cast alloy consist of the eutectic boride, pearlite, and ferrite. Moreover, the as-cast eutectic boride structures are greatly refined when titanium and nitrogen are added. The boride area fraction, average boride area, Rockwell hardness, etc., are also investigated systemically. The wear behaviors of medium carbon Fe–B cast alloy are studied by a three-body abrasive wear tester. The results show that the wear weight loss of Fe–B cast alloy with titanium and nitrogen elements is lower than that of the ordinary Fe–B cast alloy. Meanwhile, the wear mechanism of Fe–B cast alloy with different titanium and nitrogen concentrations is described and analyzed. 相似文献
3.
Jianjun Zhang Yimin Gao Jiandong Xing Shengqiang Ma Dawei Yi Jingbo Yan 《Tribology Letters》2011,44(1):31-39
This research work studies the effects of chromium on microstructure and abrasion resistance of Fe–B cast alloy. The results
show that eutectic boride changes from continuous network to less continuous and matrix changes from pearlite to martensite
with the increase in chromium content in the alloy. Meanwhile, an increase in chromium addition in the alloy leads to an increase
in the chromium content in M2B-type boride because chromium can enter boride by substituting for iron in Fe2B. Under two-body wear, Fe–B cast alloy exhibits excellent wear resistance. When alloys are tested against soft abrasive,
chromium can markedly improve the wear resistance of Fe–B cast alloy, whereas excessive chromium can reduce the wear resistance.
The wear resistance of Fe–B cast alloy increases first and then decreases with the increase in chromium. But when tested against
hard abrasive, since the hardness of SiC is much higher than that of M2B boride, an increase in chromium content marginally increases the wear resistance. Weight losses of Fe–B cast alloy increase
with the increase in the load and exhibit the linear relationship. 相似文献
4.
The abrasion wear resistance of Fe–32Cr–4.5C wt% hardfacing alloy was investigated as a function of matrix microstructure.
In this study, the alloy was deposited on ASTM A36 carbon steel plates by the shielded metal arc welding (SMAW) process and
the as-welded matrix microstructure was changed into ferrite, martensite, and tempered martensite by heat treatment processes.
The Pin-on-disk test results show that under low (5 N) and high (20 N) load conditions, the wear resistance behavior of the
as-welded matrix sample is 20 and 15% higher, respectively, than the martensitic matrix sample, although the bulk hardness
of the as-welded matrix is 5% lower. The ferritic matrix sample has the poorest wear resistance behavior which is less than
half of that of the as-welded matrix one. Micro-ploughing, micro-cutting, and micro-cracking are recognized as the micro-mechanisms
in the material removal in which the proportion of micro-ploughing mechanism increased by increasing matrix toughness. 相似文献
5.
In this study, a hydroxyapatite composite coating was prepared by a sol–gel technique on the micro-arc oxidation (MAO)-coated AZ31 Mg alloy to seal the micro-pores. The composite coating achieved a larger hardness value and two times thickness more than pure MAO coating. The corrosion and wear resistance of the sol–gel/MAO coating in simulated body fluid were investigated compared to MAO coating. It was found that the composite coating presented a positive corrosion potential and a lower corrosion current density than MAO coating. The sol–gel/MAO composite coating could provide more effective barrier against corrosive ions than single MAO coating for AZ31 alloy. In the wear tests, a ball-on-disk tribometer was used to study the effect of loads on the wear properties of the coatings at 37 °C. The wear resistance of sol–gel/MAO composite coatings was apparently superior to MAO coating. The wear mechanisms of abrasion and adhesion in composite coatings are investigated. Finally, two physical models for the corrosion and sliding wear mechanisms of sol–gel/MAO composite coatings are proposed, respectively. 相似文献
6.
Ahmad A. Sorour Holger W. Strauss Richard R. Chromik Mathieu Brochu 《Tribology Letters》2011,44(2):269-278
The spark plasma sintering (SPS) process was used to fabricate a bulk Fe–Cr–B alloy (known as Armacor M) from gas-atomized
powders. The purpose of this work is to study the microstructure, hardness and tribology of this sintered bulk alloy. Post
microstructure and mechanical characterizations were performed to investigate the effects of wear on the microstructure and
mechanical properties. Microstructural analysis using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy
dispersive spectroscopy (EDS) showed that SPS successfully produced a fully dense bulk material containing 67 vol.% Cr1.65Fe0.35B0.96 particles dispersed in 33 vol.% solid solution matrix consisting of Fe, Cr and Si. Using nanoindentation, the hardness of
the Cr1.65Fe0.35B0.96 particles and the matrix was found to be 24 and 6 GPa, respectively. From microindentation, the bulk hardness of the sintered
alloy was 9.7 GPa (991 HV). Dry sliding wear testing under mild conditions (i.e., initial Hertzian mean contact pressure of
280 MPa) was conducted against a stainless steel pin. The steady state coefficient of friction against Armacor M was about
0.82. The wear of Armacor M proceeded primarily by adhesive and mild oxidative wear. The wear volume for Armacor M was 80%
less than that of carbon steel and its wear rate was 5.53 × 10−6 mm3 N−1 m−1. 相似文献
7.
In order to improve the corrosion–wear resistance properties of steels in molten aluminum, novel Fe–Cr–B cast steels with different boron concentrations were prepared. The steels were investigated at 750 °C for 0.5 h using a ring-block corrosion–wear test, and the interfacial morphologies were examined. Results showed that the corrosion–wear resistance of the Fe–Cr–B cast steel was three times that of H13, and benefited greatly from the effects of the primary Cr-rich Fe2B, which bore the main load during the corrosion–wear test. The corrosion–wear behavior of the coarse primary Cr-rich Fe2B in molten aluminum was clearly different from that in static molten aluminum. 相似文献
8.
Short fiber reinforcement plays a definite role in governing the performance of a composite through the improvement of different material properties. The present investigation deals with the effect of aramid pulp and lapinas fiber on the friction and wear characteristics of a composite made from phenolic resin modified by powdered acrylonitrile butadiene rubber (NBR) on a pin-on-disc tribometer. Four composites, containing 10, 20, 30, and 40 wt% of aramid pulp with respect to phenolic resin content, were prepared. Another four composites, containing 50, 100, 200, and 300 wt% of lapinas fiber with respect to phenolic resin content, were also made. It was found that the two different fibers have distinctly different contributions to the friction and wear properties of the composites. It was also found that the incorporation of aramid pulp enhances friction stability of the composites much better than that of lapinas fiber. The change in surface morphology of these composites was studied by scanning electron microscopy (SEM) before and after the friction test. SEM images of friction samples containing aramid pulp corroborated the occurrence of wear through an adhesive wear mechanism, whereas the lapinas fiber–containing composites showed an abrasive wear mechanism. 相似文献
9.
In this study, the tribological behavior of ultra-high-molecular-weight polyethylene (UHMWPE) against a GCr 15 steel ball during fretting wear conditions was investigated using an oscillating reciprocating tribometer. The aim of this study was to characterize the critical value of normal load and stroke corresponding to this transition in UHMWPE worn surface at room temperature. Results showed that there existed a critical value of load or stroke at fixed condition. The friction coefficient and wear volume loss of UHMWPE at or near the critical values of load and stroke exhibited extreme changes. Based on observation of the worn surface by scanning electron microscopy (SEM) and 3D surface profiler measurements, it can be found that damage to the worn surface can be linked to the contact load and stroke. In addition, results showed that during the process of fretting wear under different load or stroke conditions, the gross slip regime dominated throughout the whole test period. 相似文献
10.
Yu Lei Qingsen Meng Lei Zhuang Shaoping Chen Lifang Hu Huiling Cheng 《Tribology Letters》2014,56(3):435-442
In this article, field-activated and pressure-assisted synthesis was employed to synthesize an ultra-hard, super-abrasive AlMgB14–TiB2 composite ceramic. The friction and wear performance of the AlMgB14–TiB2 composite were evaluated in ambient air at temperatures up to 800 °C by using a reciprocating ball-on-disk high-temperature tribometer. X-ray diffraction experiments were performed to study the crystal structure of worn surfaces of AlMgB14–TiB2 specimens at various temperatures. Scanning electron microscopy and energy dispersive analysis were used to examine the worn surface features and chemical composition of the AlMgB14–TiB2 composite, respectively. Results showed that the friction coefficient of the AlMgB14–TiB2 composite ranged from 0.45 to 0.55 below 300 °C, while the data obtained at 500 and 600 °C were about 0.65. The damage mechanism is transformed from mild abrasive damage at room temperature to adhesive wear at elevated temperature. In the case of 800 °C, the AlMgB14–TiB2 composite exhibited the lowest friction coefficient as the formation of a lubricious oxide film on the wear track. 相似文献
11.
The friction and wear behavior of ultra-high molecular weight polyethylene (UHMWPE) sliding against GCr15 steel and electroless
Ni-P alloy coating under the lubrication of seawater was investigated and compared with that under dry sliding and lubrication
of pure water and 3.5 wt.% NaCl solution, respectively. It was found that under the lubrication of aqueous medium, the friction
and wear behavior of UHMWPE mainly depended on the corrosion of counterface and the lubricating effect of the medium. Because
of serious corrosion of counterface by the medium, the wear rates of UHMWPE sliding against GCr15 under the lubrication of
seawater and NaCl solution were much larger than that under other conditions, and such a kind of wear closely related to the
corrosion of counterface can be reckoned as indirect corrosive wear. However, when sliding against corrosion-resistant Ni–P
alloy under the lubrication of seawater, the lowest coefficient of friction and wear rate of UHMWPE were obtained, owing to
superior lubricating effect of seawater. Moreover, periodic ripple patterns were observed on the worn surfaces of UHMWPE sliding
against GCr15 under the lubrication of seawater and NaCl solution, which were ascribed to the intelligent reconstruction of
surface microstructure of UHMWPE upon large plowing effect of the counterface asperities. Based on scanning electron microscopic
(SEM) and three-dimensional (3D) profile analyses of the worn surfaces of UHMWPE, a stick–slip dynamic mechanism was proposed
to illustrate the pattern abrasion of UHMWPE.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
Polyimide/Epoxy resin–molybdenum disulfide bonded solid lubricant coatings (denoted as PI/EP-MoS2) were prepared. The influence of polyfluo-wax (denoted as PFW) on the microhardness and friction and wear behavior of as-prepared PI/EP-MoS2 lubricant coating was measured using a microhardness tester and a reciprocating ball-on-disc tribometer, respectively. The worn surfaces of the lubricant coatings were observed with a scanning electron microscope, and their wear rate was determined with a Micro XAM surface mapping microscope. Moreover, the transfer films formed on the counterpart steel ball surfaces were analyzed by X-ray photoelectron spectroscopy. Results indicate that the incorporation of a proper content of PFW filler is effective at improving the antifriction performance of the PI/EP-MoS2 lubricant coating while maintaining better wear resistance. Moreover, the friction coefficient of the lubricant coating decreases with increasing content of PFW from 2 to 10%, and the one with a filler content over 6% PFW has a steady friction coefficient of 0.07. The improvement in the antifriction performance of the lubricant coating with the incorporation of the PFW filler is attributed to the excellent lubricity of homogeneously distributed PFW. 相似文献
13.
Basic studies of abrasive wear have been performed by controlled grooving in a modified impact tester equipped with a cemented carbide tip. Specimen holders were constructed to permit normal and tangential force measurements during grooving and to enable quick-stop tests. The grooving energy is read directly from the standard pendulum meter or integrated from tangential force curves. A series of metals were studied by single-tip grooving and the grooving energy was plotted versus weight loss W within a large W interval. Mettallographic studies reveal characteristic friction layers in the groove bottom and walls and also show that the development of these layers is governed by the mechanisms of chip formation. A particular purpose of this work is to find relations between internal structure and microhardness profiles on one hand and grooving forces/energy and wear resistance on the other. There are indications that the specific grooving energy e = E/W can be used to predict abrasive wear resistance under widely varying conditions from “mild” to “severe” wear. 相似文献
14.
The tribological properties of Ni–17.5Si–29.3Cr alloy against Si3N4 under water lubrication conditions were studied on a ball-on-disc reciprocating 1tribotester. The effects of load and sliding
speed on tribological properties of the alloy were investigated. The worn surfaces of the alloy were examined with SEM, TEM
and an X-ray photoelectron spectroscope (XPS). It was found that the tribological properties of the alloy were closely dependent
on the sliding conditions. Wear rate with the load of the alloy increased slightly at low and moderate load and increased
dramatically at high load. Wear rate with the sliding speed of the alloy increased slightly at low and moderate sliding speed
and increased dramatically at high sliding speed, which showed the same trend as that with the load. The friction coefficient
increased with the load (especially at high load), and decreased with sliding speed at low sliding speed and increased significantly
at high sliding speed. Wear mechanism of the alloy was mainly microploughing and delamination at low and moderate load and
transformed to microfracture and delamination at high load. 相似文献
15.
Engine-related improvements such as more efficient engine components, improved engine oils, and high-performance coating materials, need to be verified in terms of their effects on the tribological performance of the piston ring/cylinder bore system. The main purpose of this research is to develop an abrasive wear model for the piston ring/cylinder bore system during steady-state operation by considering the effects of temperature, load, oil degradation, surface roughness, and material properties. The model can be used either in theoretical modeling or integrated with finite element analysis. Based on a laboratory simulator, a three-body abrasive wear model has been developed to model the wear progression of the piston ring/cylinder bore system during steady state operation. The proposed novel abrasive wear model addresses the effects of temperature, load, oil degradation, surface roughness, and material properties. The feasibility of the proposed model is illustrated by a numerical example. 相似文献
16.
The Cu–Fe matrix continuous braking friction materials using SiC as abrasive were fabricated by powder metallurgy technique, and the effect of content and size of SiC were investigated. The tribological properties of friction materials sliding against AISI 1045 steel ring were carried out on a block-on-ring tester at different loads and sliding speeds. The strengthening effect of nano-SiC (55 nm) was superior to that of micro-SiC (70 μm) of the tribological properties for friction materials. The friction coefficients of friction materials increased with increasing nano-SiC content. However, the wear rates decreased with increasing nano-SiC content and then increased when the content of nano-SiC particle exceeded 10 wt%. The specimen contained 10% nano-SiC had the best tribological properties at different testing conditions. 相似文献
17.
An Fe–5 wt%Cr alloy was nitrided in gaseous atmosphere at 590 °C for 12 h. In the resulting diffusion layer, nitrides precipitate on a nanometre scale. The microstructure in the diffusion layer was characterised by optical microscopy and hardness measurements. The morphology, volume fraction and chemical composition of the nitrides were determined by means of atom probe tomography. The orientation of the nitrides with respect to the matrix was investigated using three-dimensional field ion tomography. The evolution of the nitrides was studied at different depths from the surface and their nanoscopic features were correlated with the obtained hardness profile. At a depth of 270 μm from the surface, the first stages of nitride formation could be analysed. 相似文献
18.
In practice, the sliding speed is an important parameter for materials applied in sliding condition. We have conducted an
experimental study to explore the effect of sliding speed on friction and wear performance of a copper–graphite composite.
The sliding tests were carried out over a wide range of speeds with a pin-on-disc configuration. The results show that there
is a critical speed at which there is a transition of the friction and wear regimes of the composite. In addition, the formation
of a lubricant layer on the contact surface (surface modification) determines the actual tribological performance of the composite.
The wear mechanisms in different wear regimes are also discussed. 相似文献
19.
Ki Nam Kim Hye Won Kim Gyeong Su Shin Myung Chul Park Jun Ki Kim Seon Jin Kim 《Tribology Letters》2012,48(3):417-424
The effects of Ni and Mn concentrations and also the impact velocity on the solid particle erosion behavior of Fe?C12Cr?C0.4C?CxNi/Mn (x?=?5 and 10) alloys were investigated with respect to strain-induced martensitic transformation. The critical strain energy (CSE), which is defined as the energy required to initiate the martensitic transformation increased with increasing Ni and Mn concentrations. As the impact velocity decreased, the solid particle erosion resistance of the low CSE alloy improved compared to that of the high CSE alloy under the given ranges of impingement angles and impact velocities. This result was most likely due to an increase in the volume fraction of martensite that formed during the solid particle erosion test in the low CSE alloy when the impact velocity was decreased. 相似文献
20.
The dry sliding wear tests were performed for AZ91D alloy under the loads of 12.5–300 N and the ambient temperatures of 25–200 °C.
We studied the wear characteristics of AZ91D alloy as a function of the normal load and the ambient temperature. The mild-to-severe
wear transition occurred with increasing the load and the critical load reduced with the ambient temperature rising. However,
no matter how high the ambient temperature was in the range of 25–200 °C, the mild wear prevailed under the lower loads. Especially,
the AZ91D alloy presented a lower wear rate at 200 °C than at 25 and 100 °C under the low loads of 12.5–25 N, but vice versa
under the loads of more than 25 N. These phenomena seem to be contradictory to the popular view that the mild-to-severe wear
transition is controlled by the critical surface temperature. These may be attributed to a thick and hard mechanical mixing
layer (MML) containing the mixture of MgAl2O4 and Mg on the worn surface. The MML thickened with increasing the ambient temperature (under the low loads), effectively
reduced wear and markedly elevated the critical surface temperature. The oxidative wear and delamination wear successively
predominated in the mild wear regime; the gross plastic-induced wear would prevail in the severe wear regime. 相似文献