Study of Aging Treatment on the Coating with 3%Cu/Fe-Based Alloy Fabricated by Laser Cladding

2011 ◽  
Vol 391-392 ◽  
pp. 474-478
Author(s):  
Fang Zhou ◽  
Tao Zhu ◽  
Gao Li
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Aging Treatment ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Preferred Direction

The composite coating with 3%Cu/ Fe-based alloy was fabricated on Q235A steel by laser cladding. The effect of aging treatment on the microstructure and properties of laser-cladded coating was investigated. The results show that there is α-Fe phase accompanied by the M7C3 with an orthorhombic crystal structure and M23C6 in the cladded coating. The preferred direction at (110) crystal plane exist in the α-Fe. The TEM observation shows that the high density dislocations exist in the martensite. When the cladded coatings are aged at 550 for 20 h and 30 h respectively, the ε-Cu particles precipitate dispersedly from the supersaturated α-Fe solid solution along the M7C3. The ε-Cu particles play the role of anchoring dislocation. The microhardness and the wear resistance of coatings are increased greatly after the aging treatment. The coating aged for 20 h at 550 presents the best wear resistance in the tested coatings. With aging time, the microhardness and the wear resistance of cladding coating are decreased.

Research on Microstructure and Hardness of Laser Cladding Using the Mixed Powder of Nano-TiC and Ni-Based Alloy

2020 ◽  
Vol 976 ◽  
pp. 9-14 ◽  
Author(s):  
Wei Zhang ◽  
Qiu Hong Feng ◽  
Wei Zhong Zhang
Keyword(s):  
Solid Solution ◽  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
High Speed ◽  
Scanning Speed ◽  
Mixed Powder ◽  
Reinforced Composite ◽  
Average Hardness ◽  
Cladding Material

Aiming at the problem of poor high-temperature wear-resistance of rope clamp used in super-high speed elevators, the experiments of laser cladding to prepare carbide reinforced composite coating were made. nanoTiC powder, Ni-based alloy powder were used as cladding material. The microstructure and hardness of composite coating were tested by relevant equipments. The research results show that the composite coating is made up of TiC, Cr3C2, Fe3C and Fe-Ni-Cr-C HYPERLINK "javascript:void (0);" solid solution. When the content of TiC is 10%, 30%, the morphology of TiC is presented as dendrite-like and the morphology of HYPERLINK "javascript:void (0);" solid solution is presented as cellular-like. When the content of TiC is 50%, the morphology of TiC is presented as block-like, lath-like. There are some microcracks on grain boundaries. At the content of 30%, laser power 1.5KW, scanning speed 600mm/min, the laser cladding has no crack and hole. The average hardness of composite coating is 701HV0.2. Using this technology to the surface strengthening of elevator parts, the wear resistance and service life can be greatly improved.

Spherulitic crystal growth in the prodissoconch larval of Crassostrea virginica

1983 ◽  
Vol 41 ◽  
pp. 518-519
Author(s):  
George G. Cocks ◽  
Louis Leibovitz ◽  
DoSuk D. Lee
Keyword(s):  
Crystal Structure ◽  
Crassostrea Virginica ◽  
Crystal Orientation ◽  
Developmental Changes ◽  
Gastrula Stage ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Stages Of Growth ◽  
Early Stages ◽  
Initial Deposition

Our understanding of the structure and the formation of inorganic minerals in the bivalve shells has been considerably advanced by the use of electron microscope. However, very little is known about the ultrastructure of valves in the larval stage of the oysters. The present study examines the developmental changes which occur between the time of conception to the early stages of Dissoconch in the Crassostrea virginica(Gmelin), focusing on the initial deposition of inorganic crystals by the oysters.The spawning was induced by elevating the temperature of the seawater where the adult oysters were conditioned. The eggs and sperm were collected separately, then immediately mixed for the fertilizations to occur. Fertilized animals were kept in the incubator where various stages of development were stopped and observed. The detailed analysis of the early stages of growth showed that CaCO3 crystals(aragonite), with orthorhombic crystal structure, are deposited as early as gastrula stage(Figuresla-b). The next stage in development, the prodissoconch, revealed that the crystal orientation is in the form of spherulites.

scholarly journals Crystal Structures of New Ivermectin Pseudopolymorphs

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 172
Author(s):  
Kirill Shubin ◽  
Agris Bērziņš ◽  
Sergey Belyakov
Keyword(s):  
Crystal Structure ◽  
Molecular Conformation ◽  
Methyl Tert Butyl Ether ◽  
Minor Role ◽  
Scanning Calorimetry ◽  
Orthorhombic Crystal ◽  
Monoclinic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Space Group ◽  
Structure Space

New pseudopolymorphs of ivermectin (IVM), a potential anti-COVID-19 drug, were prepared. The crystal structure for three pseudopolymorphic crystalline forms of IVM has been determined using single-crystal X-ray crystallographic analysis. The molecular conformation of IVM in crystals has been compared with the conformation of isolated molecules modeled by DFT calculations. In a solvent with relatively small molecules (ethanol), IVM forms monoclinic crystal structure (space group I2), which contains two types of voids. When crystallized from solvents with larger molecules, like γ-valerolactone (GVL) and methyl tert-butyl ether (MTBE), IVM forms orthorhombic crystal structure (space group P212121). Calculations of the lattice energy indicate that interactions between IVM and solvents play a minor role; the main contribution to energy is made by the interactions between the molecules of IVM itself, which form a framework in the crystal structure. Interactions between IVM and molecules of solvents were evaluated using Hirshfeld surface analysis. Thermal analysis of the new pseudopolymorphs of IVM was performed by differential scanning calorimetry and thermogravimetric analysis.

MICROSTRUCTURES AND DRY SLIDING WEAR RESISTANCE OF THE LASER CERAMICS COMPOSITE COATING ON PURE Ti

2012 ◽  
Vol 19 (03) ◽  
pp. 1250017 ◽  
Author(s):  
PENG LIU ◽  
YUANBIN ZHANG ◽  
HUI LUO ◽  
YUSHUANG HUO
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Dry Sliding Wear ◽  
X Ray Diffraction ◽  
Phase Constituent ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Modification Technique ◽  
Surface Performance

In this study, Al–Ti–Co was used to improve the surface performance of pure Ti . Laser cladding is an important surface modification technique, which can be used to improve the surface performance of pure Ti . Laser cladding of the Al–Ti–Co + TiB2 pre-placed powders on pure Ti can form ceramics reinforced the composite coating, which improved the wear resistance of the substrate. Characteristics of the composite coating were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness and wear tests. And the laser-cladded coating can also have major dilution from the substrate. Due to the action of the fine grain strengthening and the phase constituent, the wear resistance and microhardness of pure Ti surface were greatly improved.

scholarly journals Laser Cladding of Ni-Co-W Composite Coating on Stainless Steel to Enhance Wear Resistance

2021 ◽  
Author(s):  
Linlin ZHANG ◽  
Dawei ZHANG
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Eutectic Structure ◽  
Wear Properties ◽  
Fine Grained ◽  
Noticeable Improvement ◽  
Enhance Wear Resistance

Ni-Co-W composite coatings modified by different contents of Co-based alloy powder in the Ni-based alloy with 35 wt.% WC (Ni35WC) were deposited on stainless steel by laser cladding. The influence of compositional and microstructural modification on the wear properties has been comparatively investigated by XRD, SEM, and EDS techniques. It was found that the austenite dendrites in the modified coating adding 50 wt.% Co-based alloy were refined and a lot of Cr23C6 or M23(C, B)6 compounds with fine lamellar feature were formed around austenitic grain boundaries or in the intergranular regions. The contribution of element Co to the modification of Ni35WC coating is that it cannot only promote the formation of more hard compounds to refine austenite grains, but also refine the size of precipitates, and change the phase type of eutectic structure as a result of disappeared Cr boride brittle phases. A noticeable improvement in wear resistance is obtained in the Ni35WC coating with 50 wt.% Co-based alloy, which makes the wear rate decreased by about 53 % and 30% by comparison to that of the substrate and the Ni35WC coating, respectively. It is suggested that the improvement is closely related to the composite coating being strengthened owing to the increase of coating hardness, formation of a fine-grained microstructure caused by Co, and fine hard precipitate phases in the eutectic structure.

scholarly journals (R)-Baclofen [(R)-4-amino-3-(4-chlorophenyl)butanoic acid]

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Feodor Belov ◽  
Alexander Villinger ◽  
Jan von Langermann
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Title Compound ◽  
Single Crystal Xrd ◽  
Butanoic Acid ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Space Group ◽  
Structure Space

This article provides the first single-crystal XRD-based structure of enantiopure (R)-baclofen (form C), C10H12ClNO2, without any co-crystallized substances. In the enantiopure title compound, the molecules arrange themselves in an orthorhombic crystal structure (space group P212121). In the crystal, strong hydrogen bonds and C—H ... Cl bonds interconnect the zwitterionic molecules.

Thermal enhancement of 2H11/2→4I15/2 up-conversion luminescence of Er3+ doped K2Yb(PO4)(MoO4) phosphors

2021 ◽  
Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Zhang ◽  
Yuhang Zhang ◽  
Siying Ran ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Reaction Method ◽  
X Ray ◽  
Thermal Enhancement

Er3+ with different concentrations doped K2Yb(PO4)(MoO4) phosphors were prepared by a solid-state reaction method, and the layered orthorhombic crystal structure of the samples was confirmed by X-ray diffraction (XRD). Under...

Strengthening Mechanism and Wear Resistance of Al2O3/Fe901 Composite Coating Prepared by Laser Cladding

2019 ◽  
Vol 39 (5) ◽  
pp. 0514001
Author(s):  
周建忠 Zhou Jianzhong ◽  
何文渊 He Wenyuan ◽  
徐家乐 Xu Jiale ◽  
谭文胜 Tan Wensheng ◽  
孟宪凯 Meng Xiankai ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Strengthening Mechanism
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