scholarly journals Wear Resistance Improvement of Copper Alloys Using a Thermochemically Obtained Zinc-Rich Coating

2020 ◽  
Vol 5 (9) ◽  
pp. 1089-1096
Author(s):  
Omar Alvarez ◽  
Carlos Valdés ◽  
Arturo Barba ◽  
Rafael González ◽  
Raúl Valdéz ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Chemical Analysis ◽  
Diffraction Analysis ◽  
Copper Alloys ◽  
Wear Test ◽  
Zinc Powder ◽  
X Ray Diffraction ◽  
Pure Zinc ◽  
X Ray ◽  
Thermochemical Process

It has been developed a thermochemical process that has been applied on copper alloys: brass and bronze, using pure zinc powder, obtaining a zinc-rich wear protective coating. The layers obtained by a diffusion process, on brass (alloy C36000) and bronze specimens (alloy SAE 62), were characterized using a scanning electron microscope, EDAX microanalysis, Vickers microhardness, X-Ray diffraction analysis, and sliding wear test. The chemical analysis showed a layer composition of 62 % Zn and 38 % Cu, on average. The microhardness for thermochemical treated brass was 496HV and 598HV for bronze; thus, a microhardness increase for brass is 468% and 532% for bronze. It was made an X-Ray diffraction analysis, confirming the results obtained with the chemical analysis and crystalline structure for coating. It showed the presence of Cu64Zn36 and Cu5Zn8 phases. The wear tests demonstrated that treated specimens show better wear resistance than non-protected specimens.

Microstructure and wear resistance of Cuss-toughened Cr5Si3/CrSi metal silicide alloys

2005 ◽  
Vol 20 (5) ◽  
pp. 1122-1130 ◽  
Author(s):  
Y.X. Yin ◽  
H.M. Wang
Keyword(s):  
Solid Solution ◽  
Wear Resistance ◽  
Sliding Wear ◽  
Room Temperature ◽  
Wear Test ◽  
Melting Process ◽  
Dry Sliding Wear ◽  
Metal Silicide ◽  
X Ray Diffraction ◽  
X Ray

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.

Effect of Varying Wt% of TiC on Mechanical and Wear Properties of RZ5-TiC In-Situ Composite

2018 ◽  
Vol 8 (2) ◽  
pp. 45-56 ◽  
Author(s):  
Deepak Mehra ◽  
M.M. Mahapatra ◽  
S. P. Harsha
Keyword(s):  
Wear Resistance ◽  
Wear Behavior ◽  
Wear Test ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
X Ray ◽  
Tic Particle ◽  
Mechanical And Microstructural Properties ◽  
Sliding Distance

The purpose of this article is to enhance the mechanical properties and wear resistance of the RZ5 alloy used in the aerospace application by adding TiC particles. The present study discusses processing of in-situ RZ5-TiC composite fabricated by self-propagating high temperature (S.H.S.) method and its wear behavior. The effects of TiC particle on mechanical and microstructural properties of the composite are studied. The wear test is performed by varying the sliding distance and applied load. The composite is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results exhibited the properties like strength and hardness of RZ5-10wt%TiC composite has been increased considerably, while grain size is decreased as compared to the RZ5 alloy. The fractography indicated mixed mode (quasi-cleavage and ductile feature) failure of the composites. The wear results showed improvement in wear resistance of the composite. The FESEM showed dominate wear mechanisms are abrasion, ploughing grooves.

scholarly journals Microstructure, tribological performances, and wear mechanisms of laser-cladded TiC-reinforced NiMo coatings under grease-lubrication condition

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhu Weixin ◽  
Kong Dejun
Keyword(s):  
Wear Resistance ◽  
Wear Test ◽  
Depth Of Field ◽  
X Ray Diffraction ◽  
Grease Lubrication ◽  
Wear Performance ◽  
Friction Process ◽  
X Ray ◽  
Wear Rates ◽  
Lubrication Condition

Abstract NiMo-5%TiC, NiMo-15%TiC, and NiMo-25%TiC coatings were prepared on GCr15 steel by laser cladding (LC). The microstructure and the phases of the obtained coatings were analyzed using ultra-depth-of-field microscopy (UDFM) and X-ray diffraction (XRD), respectively. A ball-on-disk wear test was used to analyze the friction-wear performance of the substrate and the NiMo-TiC coatings under grease-lubrication condition. The results show that the grain shape of NiMo-TiC coatings is dendritic. The wear resistance of NiMo-TiC coatings is improved by the addition of TiC, and the depths of the worn tracks on the substrate and on the NiMo-5%TiC, NiMo-15%TiC, and NiMo-25%TiC coatings are 4.183 μm, 2.164 μm, 1.882 μm, and 1.246 μm, respectively, and the corresponding wear rates are 72.25 μm3/s/N, 32.00 μm3/s/N, 18.10 μm3/s/N, and 7.99 μm3/s/N, respectively; this shows that the NiMo-25%TiC coating has the highest wear resistance among the three kinds of coatings. The wear mechanism of NiMo-TiC coatings is abrasive wear, and the addition of TiC plays a role in resisting wear during the friction process.

Substrate Dependent Morphologies and Luminescence Properties of ZnO Nanostructures Prepared by Thermal Evaporation

2009 ◽  
Vol 60-61 ◽  
pp. 278-282 ◽  
Author(s):  
Bin Ping Zhuang ◽  
Fa Chun Lai ◽  
Li Mei Lin ◽  
Ming Bao Lin ◽  
Yan Qu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Thermal Evaporation ◽  
Zinc Powder ◽  
Substrate Material ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Pure Zinc ◽  
X Ray ◽  
Structure Morphology ◽  
Quartz Substrates

High density ZnO nanostructures were fabricated on Au coated Si and quartz substrates through once and the same oxidative evaporation of pure zinc powder. The coated side of the substrate was intentionally positioned in two directions of face and back to the zinc sources. Structure, morphology and optical properties of the samples were investigated by scanning electron microscopy, X-ray diffraction, Raman spectra and room temperature photoluminescence measurements. The results showed that the samples on the different substrates with different directions have three different morphologies, including film-, rod- and comb-like nanostructures. Photoluminescence spectra of the samples showed the various bands centered in UV (380-390 nm), blue (470-490 nm), green (500-550 nm) and orange (610-620 nm) region. It demonstrates that the substrate material and the direction of substrate significantly affect the growth of ZnO nanostructures.

Wear resistance of hydrogenated high nitrogen steel at dry and solid state lubricants assistant friction

2019 ◽  
Vol 2 (98) ◽  
pp. 57-67
Author(s):  
O.A. Balitskii ◽  
V.O. Kolesnikov ◽  
A.I. Balitskii
Keyword(s):  
Wear Resistance ◽  
Diffraction Analysis ◽  
Friction Surface ◽  
Rolling Friction ◽  
X Ray Diffraction ◽  
High Nitrogen ◽  
X Ray ◽  
Nitrogen Steel ◽  
Nitrogen Steels ◽  
Friction Surfaces

Purpose: This paper is devoted the investigation hydrogen influence on of wear resistance of high nitrogen steel (HNS) at dry and solid state lubricants assistant friction. It has been established that after hydrogenation at 250 N loading the wear rate increased by 2.9 ... 4.1 times. Microhardness of hydrogenated layer was 7.6 ... 8.2 GPa, that is increased after hydrogenation in two times. After adding the (GaSe)xIn1-x compounds to the tribo conjugates by X-ray diffraction analysis it has been established the appearance of new phases which formed during the friction process and detected on the friction surface. Design/methodology/approach: This work presents research results concerning the comparative tests of high nitrogen steels in the circumstances of dry rolling friction. It was conducted the experiments to determine the tribological properties of high-nitrogen steels under rolling friction. The test pieces were manufactured in the form of rollers, and rotated with a linear velocity 2.27 m/s (upper roller), 3.08 m/s (bottom roller). Upper roller is made from HNS was subjected for hydrogenation. Analysis of friction surfaces indicates the complex mechanism of fracture surfaces. The results of the local X-ray analysis and X-ray diffraction analysis has been established the appearance of new phases and elements on the friction surface. Findings: It has been found that the level of wear resistance of the investigated materials under hydrogenation. Compounds realize chemisorption, tribochemical mechanisms of the formation of thin protective (anti-wear, antifriction) layers on metal surfaces. Research limitations/implications: An essential problem is the verification of the results obtained using the standard mechanical tests, computer-based image analysis and other methods. Practical implications: The observed phenomena can be regarded as the basic explanation of reduces the plasticity characteristics after hydrogenation. Applying the (GaSe)xIn1-x compounds as a lubricant will allow the formation of films on friction surfaces that can minimize surface wear, which will contribute to the transition to a wear-free friction mode. The protective film is a barrier to high shear and normal loads, preserving the base metal of the part and providing reduced wear and friction. Originality/value: The value of this work is that conducted experiments permit to determine the tribological properties of high nitrogen steels under rolling friction after hydrogenation. After adding (GaSe)xIn1-x compounds to the tribo conjugates after due to X-ray diffraction analysis it has been established the appearance of new phases which formed during the friction process and detected on the friction surface.

scholarly journals Improvement of the Tribological Characteristics of AISI 8620, 8640 and 52100 Steels through Thermo-Reactive Treatments

Lubricants ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 63 ◽  
Author(s):  
Triani ◽  
Mariani ◽  
Gomes ◽  
Oliveira ◽  
Totten ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Wear Test ◽  
Tribological Characteristics ◽  
Great Efficiency ◽  
X Ray Diffraction ◽  
Adhesion Test ◽  
X Ray ◽  
Knoop Microhardness

The production of vanadium and niobium carbides (VC and NbC) layers on AISI 8620, 8640, and 52100 steels may increase hardness and wear resistance of substrates. Thermochemical treatments were performed at 1000 °C for 2 and 4 h. The characterization of the treated samples was carried out by means of Knoop microhardness tests, “calotest” type microadhesive wear test, layer adhesion test according to VDI 3198 standard, and X-ray diffraction. Compact and uniform layers of VC and NbC were obtained in all treatments, with hardness up to 2500 HK and microadhesive wear resistance far superior to that of the substrates, indicating the great efficiency of these treatments for tribological applications.

Research on Properties and Flotation Feasibility of a Silver Ore Associated with Copper in Yunnan

2013 ◽  
Vol 868 ◽  
pp. 447-450
Author(s):  
Yi Jie Wang ◽  
Shu Ming Wen ◽  
Dian Wen Liu ◽  
Dan Liu
Keyword(s):  
Chemical Analysis ◽  
Diffraction Analysis ◽  
Optical Microscopy ◽  
Feasibility Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Research Results ◽  
Microscopy Analysis

Properties of the ore were studied by chemical analysis, X-ray diffraction analysis and optical microscopy analysis. Research results show that the ore contains 479.5 g/t of silver and 0.54% of copper. Silver minerals are mainly argentite, copper minerals are mainly chalcopyrite and digenite, and gangue minerals are mainly quartz and dolomite. Based on the properties of the ore, flotation feasibility study was conducted. Results show that concentrate with excellent test indexes that a Ag grade of 4787.31 g/t with a Ag recovery of 87.97% and a Cu grade of 6.01% with a Cu recovery of 87.92% were obtained under the used process and reagent system conditions.

Mechanisms of 1D Crystal Growth in Chemical Vapor Deposition: ZnO Nanowires

2012 ◽  
Vol 463-464 ◽  
pp. 1463-1467 ◽  
Author(s):  
Xin Yu Li
Keyword(s):  
Chemical Vapor ◽  
Structural Features ◽  
Nucleation And Growth ◽  
Zinc Powder ◽  
Zno Nanowires ◽  
Growth Stages ◽  
X Ray Diffraction ◽  
Pure Zinc ◽  
X Ray ◽  
Nucleation And Growth Mechanisms

Abstract. ZnO nanowires synthesis throught oxidative evaporation of pure zinc powder without catalyst is studied in detail to understand the nucleation and growth mechanisms involved with the so-called “self-catalysis” schemes. The structural features associated with different growth stages were monitored using scanning electron microscopy (SEM), describe the direct observation of the nucleation and growth process. X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) demonstrate that the as-obtained sample can be indexed to high crystallinity with wurtzite structure and only contain Zn and O without the presence of any impurities.

Microdomains in BaFeO3-y (0.35 < y < 0.50)

1990 ◽  
Vol 48 (4) ◽  
pp. 780-781
Author(s):  
M. Vallet-Regí ◽  
M. Parras ◽  
J.M. González-Calbet ◽  
J.C. Grenier
Keyword(s):  
Electron Diffraction ◽  
Chemical Analysis ◽  
Monoclinic Phase ◽  
Orthorhombic Phase ◽  
Total Iron ◽  
Zone Axis ◽  
Electron Micrograph ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Variations

BaFeO3-y compositions (0.35<y<0.50) have been investigated by means of electron diffraction and microscopy to resolve contradictory results from powder X-ray diffraction data.The samples were obtained by annealing BaFeO2.56 for 48 h. in the temperature range from 980°C to 1050°C . Total iron and barium in the samples were determined using chemical analysis and gravimetric methods, respectively.In the BaFeO3-y system, according to the electron diffraction and microscopy results, the nonstoichiometry is accommodated in different ways as a function of the composition (y):In the domain between BaFeO2.5+δBaFeO2.54, compositional variations are accommodated through the formation of microdomains. Fig. la shows the ED pattern of the BaFeO2.52 material along thezone axis. The corresponding electron micrograph is seen in Fig. 1b. Several domains corresponding to the monoclinic BaFeO2.50 phase, intergrow with domains of the orthorhombic phase. According to that, the ED pattern of Fig. 1a, can be interpreted as formed by the superposition of three types of diffraction maxima : Very strong spots corresponding to a cubic perovskite, a set of maxima due to the superposition of three domains of the monoclinic phase along [100]m and a series of maxima corresponding to three domains corresponding to the orthorhombic phase along the [100]o.

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