Study on the Tribological Properties of Low-Power Plasma-Sprayed Al-Cu-Cr Quasicrystalline Coating

2009 ◽  
Vol 610-613 ◽  
pp. 641-646 ◽  
Author(s):  
Ying Qing Fu ◽  
Feng Zhou ◽  
De Ming Yang ◽  
Nan Xiang Li ◽  
Yang Gao

Al-Cu-Cr quasicrystalline coatings were prepared by low power plasma spraying with axially-fed powder systerm. The Al65Cu20Cr15 powders were deposited on AISI 1045 steel substrate at the power ranged from 4.0 to 5.5 kW. The effects of H2/Ar flow ratio on the phase composition, microstructure and tribological properties of the as-sprayed coatings were investigated. The XRD results showed that the feedstock powders and as-sprayed coatings contained a predominant icosahedral quasicrystalline phase I-Al65Cu24Cr11 and three minor crystalline phases, including a body-centered cubic α-Al69Cu18Cr13, a monoclinic θ-Al13Cr2 (i.e. Al83Cu4Cr13) and a hexagonal ε-Al2Cu3. A qualitative analysis on the XRD patterns indicated that the volume fraction of any crystalline phase (α, ε or θ) in the coatings increased, while the quasicrystalline I-phase decreased with the rise of hydrogen (H2) content in the working gas. However, as increasing the plasma power, the friction and wear resistance of the coating were improved under the same dry sliding wear test conditions. The improvementincrease of the wear resistance may be attributed to the high hardness of quasicrystal.

2015 ◽  
Vol 220-221 ◽  
pp. 693-697 ◽  
Author(s):  
Justinas Gargasas ◽  
Algirdas Vaclovas Valiulis ◽  
Irmantas Gedzevicius ◽  
Hanna Pokhmurska

This paper present the result obtained from new experimental STEIN-MESYFIL 953 V; STEIN-MESYFIL 954 V coatings. The surfacing material was wires of 1.6 mm diameter. The tests aimed at determining wear resistance of coatings sprayed on steel substrate. The investigation shows that the tribological behaviour of new experimental thermal arc sprayed coatings is greatly affected by its microstructural constituents such as porosity, oxide inclusions, and microhardness of coatings. Results show that increasing porosity of coatings twice, it doubles the mass loss. Results for thermal sprayed coatings of all experiments showed their high wear resistance and are discussed.


2010 ◽  
Vol 97-101 ◽  
pp. 1377-1380 ◽  
Author(s):  
Jun Hai Liu ◽  
Ji Hua Huang ◽  
Jun Bo Liu ◽  
Gui Xiang Song

A new type in situ reinforcing phase TiC+Cr7C3 ceramal composite coating was fabricated on substrate of Q235 steel by plasma transferred arc (PTA) weld-surfacing process using the mixture of ferrotitanium, ferrochromium, ferroboron and ferrosilicium powders. Microstructure and wear performance of the coating were investigated by means of X-ray diffraction (XRD), scanning electron micrograph (SEM), energy dispersive X-ray analysis (EDS), microhardness tester and wear tester. Results show that the composite coating consists of TiC, primary phase Cr7C3 , (Cr,Fe)7C3 and austenite. The composite coating is metallurgically bonded to the Q235 steel substrate. TiC particles present cubic and “dendrite flower-like” shape in the composite coating. The coating has high microhardness and excellent wear resistance under dry-sliding wear test conditions.


2010 ◽  
Vol 654-656 ◽  
pp. 1856-1859 ◽  
Author(s):  
Xue Liu ◽  
Sen Yang

To extend the mould cycle duration and to reduce cost, a TiB2 particulate reinforced Cu based composite coating was produced on hot-working die steel substrate using laser cladding. The experimental results showed that TiB2 particles embedded in copper based alloy were in-situ synthesized during laser processing. An excellent bonding between the coating and the substrate was obtained. The microstructure of the coating was mainly composed of -Cu dendrites and dispersed TiB2 particles. The maximum microhardness of the coating was about 800HV0.2. The wear resistance of the coating was evaluated under room temperature dry-sliding wear test condition. Due to the presence of a large amount of TiB2 particles, the composite coating exhibited excellent wear resistance compared with that of substrate.


2011 ◽  
Vol 686 ◽  
pp. 553-560
Author(s):  
Gang Dong ◽  
Biao Yan ◽  
Qi Lin Deng ◽  
Ting Yu ◽  
Yu Xin Wang ◽  
...  

The in situ synthesized NbC particles reinforced Ni-based alloy composite coating has been successfully prepared on 1045 steel substrate by laser cladding a precursor mixture of Ni-based alloy, graphite and niobium powders. The microstructure, phase composition and wear property of the composite coating are investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and dry sliding wear test. The experiment results show that the coating is uniform, continuous and free of pores and cracks with excellent bonding between the coating and the substrate. The microstructure of the coating is mainly composed of γ-Ni dendrite, a large amount of interdendritic eutectics of M23(CB)6, N3B with γ-Ni, M23(CB)6type carbides and dispersed NbC particles. The growth mechanism of the NbC particles with cores is nucleation-growth and the un-melted niobium may act as the nucleation core for NbC, Compared to the pure Ni-based alloy coating, the hardness of the composite coating is increased about 36 %, giving a high average hardness of approximate HV0.2750. Moreover, the wear volume and wear rate of the composite coating are decreased about 50 % and 42 %, respectively. This is attributed to the presence of in situ synthesized NbC particles and their well distribution in the coating.


2005 ◽  
Vol 20 (5) ◽  
pp. 1122-1130 ◽  
Author(s):  
Y.X. Yin ◽  
H.M. Wang

Wear-resistant Cu-based solid-solution-toughened Cr5Si3/CrSi metal silicide alloy with a microstructure consisting of predominantly the dual-phase primary dendrites with a Cr5Si3 core encapsulated by CrSi phase and a small amount of interdendritic Cu-based solid solution (Cuss) was designed and fabricated by the laser melting process using Cr–Si–Cu elemental powder blends as the precursor materials. The microstructure of the Cuss-toughened Cr5Si3/CrSi metal silicide alloy was characterized by optical microscopy, powder x-ray diffraction, and energy dispersive spectroscopy. The Cuss-toughened silicide alloys have excellent wear resistance and low coefficient of friction under room temperature dry sliding wear test conditions with hardened 0.45% C carbon steel as the sliding–mating counterpart.


Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1456
Author(s):  
Qiang Wang ◽  
Runling Qian ◽  
Ju Yang ◽  
Wenjuan Niu ◽  
Liucheng Zhou ◽  
...  

In order to improve the wear resistance of 27SiMn steel substrate, Fe−based alloy coatings were prepared by laser cladding technology in the present study. In comparison to the conventional gravity powder feeding (GF) process, high−speed powder feeding (HF) process was used to prepare Fe−based alloy coating on 27SiMn steel substrate. The effect of diversified energy composition of powder materials on the microstructure and properties of coatings were systematically studied. X−ray diffractometer (XRD), optical microscope (OM) and scanning electron microscope (SEM) were used to analyze the phase structure and microstructure of Fe−based alloy coatings, and the hardness and tribological properties were measured by the microhardness tester and ball on disc wear tester, respectively. The results show that the microstructure of conventional gravity feeding (GF) coatings was composed of coarse columnar crystals. In comparison, owing to the diversification of energy composition, the microstructure of the high−speed powder feeding (HF) coatings consists of uniform and small grains. The total energy of the HF process was 75.5% of that of the GF process, proving that high−efficiency cladding can be achieved at lower laser energy. The refinement of the microstructure is beneficial to improve the hardness and wear resistance of the coating, and the hardness of the HF coating increased by 9.4% and the wear loss decreased to 80.5%, compared with the GF coating. The wear surface of the HF coating suffered less damage, and the wear mechanism was slightly adhesive wear. In contrast, wear was more serious in the GF coating, and the wear mechanism was transformed into severe adhesive wear.


2017 ◽  
Vol 8 (6) ◽  
pp. 615-620
Author(s):  
Ovidijus Jarašūnas ◽  
Olegas Černašėjus

The article deals with the flame sprayed Ni-Cr and Ni-Cr-WC coatings on construction S235 steel substrates. Before spraying, the surfaces of substrates were treated mechanically. Using the different chemical composition of Ni-Cr and Ni-Cr-WC spraying powder and additional substrate heating till 250–290 °C, were sprayed coatings. The microstructure, porosity, hardness, elastic modulus, wear resistance of the Ni-Cr and Ni-Cr-WC coatings were investigated in the work. The influence of the chemical composition and WC content of the coatings on the various physical and tribological properties of the coatings were evaluated. Also the dependence of these coatings characteristics was investigated. Straipsnyje nagrinėjamos liepsninio purškimo būdu ant konstrukcinio S235 plieno substrato užpurkštos Ni-Cr dangos. Substrato paviršiai prieš purškiant buvo apdoroti mechaniniu būdu. Naudojant skirtingos cheminės sudėties Ni-Cr ir Ni-Cr-WC purškimo miltelius ir papildomai pakaitinus substratą iki 250–290 °C temperatūros, buvo užpurkštos dangos. Darbe ištirta gautų Ni-Cr ir Ni-Cr-WC dangų mikrostruktūra, akytumas, kietumas, tamprumo modulis ir atsparumas dilimui. Įvertinta dangų cheminės sudėties ir WC karbidų įtaka įvairioms dangų fizikinėms, tribologinėms savybėms, nustatytos šių dangų charakteristikų priklausomybės.


2019 ◽  
Vol 89 (23-24) ◽  
pp. 5153-5164
Author(s):  
Meng Su ◽  
Lei Liang ◽  
Fang Ren ◽  
Weigang Yao ◽  
Mingming Yu ◽  
...  

Hybrid polyimide (PI)-polytetrafluoroethylene (PTFE)/Nomex fabric composites and Nomex-PTFE/Nomex fabric composites were prepared with benzoxazine (BOZ) as the resin binder. The tribological properties and wear mechanisms of the two composites at different temperatures were investigated using a ball-on-disk wear tester. Before sliding wear tests, a thermo-aging test, thermogravimetric analysis and dynamic mechanical analysis of PI and Nomex fibers were performed to evaluate the thermal properties of the two reinforcing fibers. After each wear test, scanning electron microscopy was employed to analyze the morphologies of the worn surfaces of the composite. The results of sliding wear tests show that the difference between the tribological properties of the two composites is small at room temperature. However, the hybrid PI-PTFE/Nomex fabric composite achieves better tribological properties at high temperatures compared with the hybrid Nomex-PTFE/Nomex fabric composite, which suffered wear failure at 240℃. It is proposed that the excellent thermal mechanical property and thermal stability of PI fibers is the main factor that endows the PI-PTFE/Nomex/BOZ composite with a more favorable tribological property at high temperatures. Moreover, the influence of the increasing temperature on the tribological properties of the two composites was also investigated.


Author(s):  
NAVEEN EASWARAN ◽  
Shanmugam Ramasamy ◽  
Roshan Nagarajan ◽  
Ramanan Nandagopal ◽  
Sripada Ragavendra Keshava Narasimha

Elemental powders of Atomized Iron (Fe), Carbon (C) and Molybdenum (Mo) were weighed and mixed in a pot mill to yield the composition of C45, C45-1%Mo and C45-2%Mo Steels, then compacted and sintered. The Sintered preforms had a density- 75% of the Theoretical Density. Then the Sintered preforms were subjected to densification to get two densities- 80% and 85% of the theoretical density through Forging. The sintered and densified preforms of alloy steels were subsequently machined to get the required wear test specimens.The experiments were conducted on a Pin-on-disc Tribometer, conforming to ASTM G99 standards, on a rotating EN32 disc. Using Minitab 16 software, the Dry Sliding wear experiments were planned using L27 Orthogonal Array.The % Theoretical Density of the Specimens (1-%Porosity), % Mo Addition, Load and Sliding Velocity were taken as input parameters, mass loss was the output parameter. It was observed that the increasing density of alloy steels adversely affects the wear resistance of the alloy steels and mass loss is increased. It was found that the addition of Mo significantly improves the wear resistance of the alloy steels irrespective of the densities .Empirical correlations for mass loss with respect to input parameters had been developed.


2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850009 ◽  
Author(s):  
H. X. ZHANG ◽  
H. J. YU ◽  
C. Z. CHEN ◽  
J. J. DAI

In order to improve the wear resistance of Ti alloys, different mass ratios of Ti-Si-Al powders were designed to fabricate hard phases reinforced intermetallic matrix composite coatings on the Ti-6Al-4V substrate by laser cladding. The corresponding coatings were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and high resolution transmission microscopy (HRTEM). The HV-1000 hardness tester and MM200 wear test machine were employed to test the hardness and the wear resistance of the composite coatings, respectively. The composite coatings mainly consisted of the reinforcements of Ti5Si3, Ti3AlC2 and Ti7Al5Si[Formula: see text] and the matrix of Ti3Al, TiAl, TiAl3 and [Formula: see text]-Ti. The micro-hardness of the Ti-35Al-15Si coating was from 956 HV[Formula: see text] to 1130 HV[Formula: see text], which was approximately 3–4 times of the substrate and the highest in the three samples. The wear rate of the Ti-35Al-15Si coating was 0.023[Formula: see text]cm3[Formula: see text][Formula: see text][Formula: see text]min[Formula: see text], which was about 1/4 of the Ti-6Al-4V substrate. It was the lowest in the three samples.


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