Research on Microstructure and Wear Resistance of (Fe,Cr)7C3/Fe Surface Gradient Composite

2015 ◽  
Vol 1120-1121 ◽  
pp. 559-563
Author(s):  
Chong Wang ◽  
Fang Xia Ye ◽  
Li Sheng Zhong ◽  
Ying Lin Yan ◽  
Yu Jun Lai ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Volume Fraction ◽  
Subsurface Layer ◽  
Composite Layer ◽  
High Volume ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
Surface Gradient

In this study, the (Fe,Cr)7C3 particles strengthened gradient composite was produced by in situ synthesis process with subsequent heat treatment from gray cast iron (HT300) and high purity chrome plate. The microstructure, phase composition and wear resistance of the composite were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and scratch tester. The results showed that the thickness of the gradient layer was about 758 μm after heat treatment at 900 °Cfor 4 h. And it can be divided into three areas depending on microstructure. The outermost layer which was ~60 μm of thickness, was the dense ceramic layer with high volume fraction of (Fe,Cr)7C3 ~90%. No obvious grain boundaries were observed. The subsurface layer was the particles dispersed layer, which was ~525 μm of thickness, with the volume fraction of (Fe,Cr)7C3 decreased to 70%. The lowermost layer was ferrite, with about 173 μm thickness. A good metallurgical bond generated between the composite layer and matrix. The depth and the width of surface scratch increased with the raising loads from 0 to 100 N, and the cracks mainly included micro-crack, tiny dens crack, mixture crack and through-wall crack. The (Fe,Cr)7C3 particles were broken and scraped when the load exceeded 80 N.

EFFECT OF HEAT TREATMENT ON (Cr, Fe)7C3/γ-Fe COATINGS IN SITU SYNTHESIZED BY VACUUM ELECTRON BEAM IRRADIATION

2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850028
Author(s):  
BINFENG LU ◽  
YUNXIA CHEN ◽  
MENGJIA XU
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Electron Beam ◽  
Impact Toughness ◽  
Composite Layer ◽  
Test Machine ◽  
Iron Matrix ◽  
Heat Treated ◽  
The Impact

(Cr, Fe)7C3/[Formula: see text]-Fe composite layer has been in situ synthesized on a low carbon steel surface by vacuum electron beam VEB irradiation. The synthesized samples were then subdued to different heat treatments to improve their impaired impact toughness. The microstructure, impact toughness and wear resistance of the heat-treated samples were studied by means of optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM), microhardness tester, impact test machine and tribological tester. After heat treatment, the primary and eutectic carbides remained in their original shape and size, and a large number of secondary carbides precipitated in the iron matrix. Since the Widmanstatten ferrite in the heat affected zone (HAZ) transformed to fine ferrite completely, the impact toughness of the heat-treated samples increased significantly. The microhardness of the heat-treated samples decreased slightly due to the decreased chromium content in the iron matrix. The wear resistance of 1000[Formula: see text]C and 900[Formula: see text]C heat-treated samples was almost same with the as-synthesized sample. While the wear resistance of the 800[Formula: see text]C heat-treated one decreased slightly because part of the austenite matrix had transformed to ferrite matrix, which reduced the bonding of carbides particulates.

MICROSTRUCTURE AND PROPERTIES OF IN SITU SYNTHESIZED ZrC-ZrB2/Fe COMPOSITE COATING PRODUCED BY GTAW

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1438-1443 ◽  
Author(s):  
ZHENTING WANG ◽  
LILI CHEN ◽  
XIANYOU ZHANG
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Volume Fraction ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Energy Dispersive Spectrum ◽  
X Ray Diffraction ◽  
Gas Tungsten Arc ◽  
C 30

A metal matrix composite coating reinforced by ZrC - ZrB 2 particulates has been successfully fabricated utilizing the in situ reaction of Zr , B 4 C and Fe pre-placed mixed powders by gas tungsten arc welding (GTAW) cladding process. Various volume fraction of ZrC - ZrB 2 particulates composite coatings were produced through cladding different weight ratios of Zr + B 4 C (30%, 50%, 70%) to improve the wear resistance of AISI1020 steel substrate. The Microstructure of the coating was analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive spectrum (EDS), meantime microhardness and wear resistance at room temperature of the composite coating were examined by means of Microhardness Tester and Wear Tester, respectively. The results show that the main phases of the composite coating obtained by GTAW are ZrC , ZrB 2 and α- Fe , ZrC exhibits hexahedron and petal shapes, ZrC - ZrB 2 compound presents acicular and clubbed forms. With the increase of content of Zr + B 4 C , the maximum volume fraction of ZrC - ZrB 2 particulates can reach 16.5%, microhardness is up to 1300HV, and wear resistance is about twenty times higher than that of AISI1020 steel substrate.

Infiltration Casting and In Situ Fabrication of NbC Particulates – Reinforced Iron Matrix Composites

2011 ◽  
Vol 284-286 ◽  
pp. 269-272
Author(s):  
Li Sheng Zhong ◽  
Yun Hua Xu ◽  
Na Na Wang ◽  
Xiao Jie Liu ◽  
Fang Xia Ye ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Volume Fraction ◽  
Niobium Carbide ◽  
Wear Testing ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Iron Matrix ◽  
Micro Cracks ◽  
Particulate Reinforced

Niobium carbide (NbC) particulates -reinforced iron matrix composites were prepared by in- situ fabrication method combining an infiltration casting with a subsequent heat treatment. The microstructure and wear-resistance of NbC particulate-reinforced iron matrix composites were studied using scanning electron microscopy, X-ray diffraction, and wear testing. The results indicate that at 1172 °C for 3 hours NbC particulate-reinforced iron matrix composites were fabricated, and the size of NbC reinforcement was 0.3–3.5 μm. The relative wear resistance of the composites was 5.4 times higher than that of gray cast iron under a 20 N load. This was achieved at 22 % NbC volume fraction. Wear of the composites manifests as grooves, broken carbide particulates and some micro-cracks.

Evolution of microstructure and phases in in situ processed Ti–TiB composites containing high volume fractions of TiB whiskers

1999 ◽  
Vol 14 (11) ◽  
pp. 4214-4223 ◽  
Author(s):  
S. S. Sahay ◽  
K. S. Ravichandran ◽  
R. Atri ◽  
B. Chen ◽  
J. Rubin
Keyword(s):  
Volume Fraction ◽  
High Volume ◽  
Comparison Method ◽  
Relative Volume ◽  
X Ray Diffraction ◽  
Volume Fractions ◽  
Structure Factors ◽  
Integrated Intensities ◽  
Evolution Of Microstructure

A series of titanium composites, with varying volume fractions of titanium monoboride (TiB) whiskers, were made by mixing various proportions of titanium (Ti) and titanium diboride (TiB2) powders followed by hot pressing. The phases present were identified by x-ray diffraction. Microstructural examination revealed three different types of TiB whisker morphologies: (i) long and needle-shaped TiB whiskers that are isolated and randomly oriented in the Ti matrix at relatively low volume fractions (0.3), (ii) colonies of refined and densely packed TiB whiskers from intermediatevolume (0.55) to high volume (0.73 and 0.86) fractions, and (iii) coarse and elongated TiB particles with a few needle-shaped whiskers at the highest volume fraction (0.92). In all the composites, TiB was found to be the predominant reinforcement. However, in Ti–TiB composites with 0.86 and 0.92 volume fractions of TiB, a significant amount of TiB2 was also present. The relative volume fractions of Ti, TiB, and TiB2 phases were estimated from the integrated intensities of diffraction peaks by the direct comparison method employing the calculated structure factors and Lorentz polarization factors. The composite microstructure, as well as the evolution of different morphologies, of TiB whiskers is discussed.

scholarly journals Characterization of γ′ Precipitates in Cast Ni-Based Superalloy and Their Behaviour at High-Homologous Temperatures Studied by TEM and in Situ XRD

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2397 ◽  
Author(s):  
Łukasz Rakoczy ◽  
Ondrej Milkovič ◽  
Bogdan Rutkowski ◽  
Rafał Cygan ◽  
Małgorzata Grudzień-Rakoczy ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Matrix Material ◽  
High Volume ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
In Situ Xrd ◽  
Transmission Electron ◽  
The Matrix

In situ X-ray diffraction and transmission electron microscopy has been used to investigate René 108 Ni-based superalloy after short-term annealing at high-homologous temperatures. Current work is focused on characterisation of γ′ precipitates, their volume fraction, evolution of the lattice parameter of γ and γ′ phases and misfit parameter of γ′ in the matrix. Material in the initial condition is characterised by a high-volume fraction (over 63%) of γ′ precipitates. Irregular distribution of alloying elements was observed. Matrix channels were strongly enriched in Cr, Co, W and Mo, whereas precipitates contain large amount of Al, Ti, Ta and Hf. Exposure to high-homologous temperatures in the range 1100–1250 °C led to the dissolution of the precipitates, which influenced the change of lattice parameter of both γ and γ′ phases. The lattice parameter of the matrix continuously grew during holding at high temperatures, which had a dominant influence on the more negative misfit coefficient.

Microstructure and Wear Properties of Fe-Based Alloy Hardfacing Layers

2011 ◽  
Vol 291-294 ◽  
pp. 201-204
Author(s):  
Lin Zong ◽  
Zheng Jun Liu
Keyword(s):  
Wear Resistance ◽  
Volume Fraction ◽  
High Volume ◽  
High Volume Fraction ◽  
High Carbon ◽  
Wear Properties ◽  
Hexagonal Shape ◽  
Complex Carbides

The in-situ M7C3–TiC carbides reinforced Fe-based hardfacing coating had been produced by prepared high-carbon ferrochromium, ferrotitanium and graphite power on 20g steel through GTAW. The microstructure and hard phases morphology were investigated by means of OP, SEM and XRD. The results showed that the microstructure of hardfacing coating consists of lamellar martensite, TiC particles and M7C3complex carbides. The TiC particles with flower-like shape and M7C3complex carbides with hexagonal shape are observed in the coating. The hardfacing coating reinforced by M7C3–TiC carbides revealed higher wear resistance than that of the substrate due to the presence of a high volume fraction of hard and wear-resistance primary M7C3carbide uniformly distributed in the fine and strong [M+M7C3+TiC] eutectics matrix.

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
Dsc Measurements ◽  
Transmission Window

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

TIN ADDITION TO THE (Bi, Pb) 2223 SYSTEM

1994 ◽  
Vol 08 (19) ◽  
pp. 1175-1183 ◽  
Author(s):  
G. RAVI CHANDRA ◽  
B. GOPALA KRISHNA ◽  
S. V. SURYANARAYANA ◽  
T. S. N. MURTHY
Keyword(s):  
Heat Treatment ◽  
Magnetic Susceptibility ◽  
Electrical Resistance ◽  
Volume Fraction ◽  
Ac Magnetic Susceptibility ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Metallic Behavior ◽  
X Ray

The effect of the addition of Sn on the superconducting properties of the Bi 1.7 Pb 0.3 Sr 2 Ca 2 Cu 3 O y system as functions of Sn concentration and heat treatment has been studied by dc electrical resistance, ac magnetic susceptibility, and X-ray diffraction. Tin addition suppresses the volume fraction of the high T c phase. Samples with Sn > 0.1 show metallic behavior up to LNT. The formation of the Ca 2 PbO 4 phase is promoted by Sn. This depletes the amount of Pb and Ca necessary for the formation of the 2223 phase, thus reducing the volume fraction of the 2223 phase. It is possible that at least a small fraction of tin substitutes some of the cationic sites of the starting composition. The results of the different measurements are presented.

Microstructure and Mechanical Properties of In Situ TiB2/6061 Composites

2012 ◽  
Vol 535-537 ◽  
pp. 14-17
Author(s):  
Long Hua Zhong ◽  
Yu Tao Zhao ◽  
Song Li Zhang ◽  
Rong Wen
Keyword(s):  
Master Alloy ◽  
Volume Fraction ◽  
X Ray Diffraction ◽  
Melt Mixing ◽  
X Ray ◽  
Mixing Method ◽  
Particulate Volume Fraction ◽  
Ti Powder ◽  
Particulate Volume

In situ TiB2/6061 composites have been successfully synthesized through chemical reaction between 6061 master alloy, Al-3B master alloy and Ti powder. The composites fabricated by direct melt mixing method was investigated by Scanning Electron Microscope (SEM), Energy Dispersive x-ray Spectroscopy (EDS) and X-Ray Diffraction (XRD), The results shown the existence of TiB2particles. The size of most TiB2particles were just in micron level, and even reached to sub-micron level. The increase in microhardness and tensile strength for the as-prepared composites with 5% particulate volume fraction (PVF) are up to 26.8% and 51.2% respectively.

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