Evolution of a Gradient Microstructure in Direct Metal Laser Sintered AlSi10Mg

2019 ◽  
pp. 331-338
Author(s):  
Amir Hadadzadeh ◽  
Babak Shalchi Amirkhiz ◽  
Brian Langelier ◽  
Jian Li ◽  
Mohsen Mohammadi
Keyword(s):  
Gradient Microstructure

Gradient Microstructure Analysis of PI-SiO2 Hybrid Tubular Films

2005 ◽  
Vol 475-479 ◽  
pp. 1575-1578
Author(s):  
Yi Kun Xu ◽  
Mao-Sheng Zhan
Keyword(s):  
Distribution Density ◽  
Sol Gel ◽  
Nano Particles ◽  
Spatial Gradient ◽  
Gradient Distribution ◽  
Moulding Process ◽  
Gradient Microstructure ◽  
Sio2 Particles ◽  
Process Energy ◽  
Insitu Polymerization

PI-SiO2 hybrid seamless tubular films with gradient microstructure were prepared by sol-gel insitu polymerization and rotational moulding process. Energy Dispersive X-Ray Spectrometry (EDS) and Field Emitter Scanning Electron Microscope (FE-SEM) were used to evaluate the spatial gradient distribution of SiO2 in the PI-SiO2 hybrid tubular films. The experimental results showed that the SiO2 particles were dispersed at nanoscale in the PI matrix, and that the size and the dispersivity of the SiO2 particles changed gradiently along the tubular film cross-section. The lower the SiO2 distribution density, the smaller the SiO2 particles. When the SiO2 content exceeded a certain value, some SiO2 nano-particles aggregated into nano-clusters with thyrsiform structure, and the nano-clusters aggregated more into limbate globoids.

Formation of the gradient microstructure of a new Al alloy based on the Al-Zn-Mg-Fe-Ni system processed by radial-shear rolling

2019 ◽  
Vol 746 ◽  
pp. 134-144 ◽  
Author(s):  
T.K. Akopyan ◽  
N.A. Belov ◽  
A.S. Aleshchenko ◽  
S.P. Galkin ◽  
Y.V. Gamin ◽  
...  
Keyword(s):  
Al Alloy ◽  
Gradient Microstructure ◽  
Radial Shear Rolling

scholarly journals Production of Surface Layer with Gradient Microstructure and Microhardess on Copper by High Pressure Surface Rolling

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 73
Author(s):  
Juying Li ◽  
Qingsong Mei ◽  
Yana Li ◽  
Beihai Wang
Keyword(s):  
High Pressure ◽  
Surface Layer ◽  
Pure Copper ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
X Ray ◽  
Pressure Surface ◽  
Surface Gradient ◽  
Pressure Time ◽  
Gradient Microstructure

Pure copper was subjected to high-pressure surface rolling (HPSR) to obtain a surface gradient layer. Effects of HPSR parameters on the surface microstructure and microhardness of Cu were investigated by using optical microscopy, transmission electronic microscopy, X-ray diffraction, and the microhardness test. The HPSR surface layer has a gradient microstructure consisting of increasingly refined grains with decreasing depth from the treated surface (DFS). The thicknesses of the refined surface layer can be up to ~1.8 mm, and the grain size of the topmost surface is down to ~88 nm, depending on the HPSR parameters including pressure, time, and temperature. Microhardness of HPSR samples increases with decreasing DFS, with a maximum of ~2.4 times that of the undeformed matrix. The present results indicated that HPSR could be an effective method for the production of a mm-thick surface layer on Cu with gradient microstructure and property.

Evolution of gradient microstructure in an extruded AZ31 rod during torsion and annealing and its effects on mechanical properties

2017 ◽  
Vol 689 ◽  
pp. 78-88 ◽  
Author(s):  
Bo Song ◽  
Hucheng Pan ◽  
Linjiang Chai ◽  
Ning Guo ◽  
Huaizhi Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gradient Microstructure

Tribological Behaviour of Gradient TiAlSiN Superhard Coatings

2016 ◽  
Vol 674 ◽  
pp. 207-212 ◽  
Author(s):  
Athanasios Mourlas ◽  
Pandora Psyllaki ◽  
Dimitrios Chaliampalias ◽  
George Vourlias ◽  
Lyliana Kolaklieva ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Tribological Behaviour ◽  
Experimental Conditions ◽  
Tin Coatings ◽  
Cathodic Arc Deposition ◽  
Transmission Electron ◽  
Gradient Microstructure ◽  
Average Factor ◽  
Gradient Coatings ◽  
Steel Substrates

The present study addresses the influence of the gradient microstructure of nanocrystalline TiAlSiN coatings on their tribological behaviour. Cathodic arc deposition was applied to elaborate such coatings, with a total thickness of 3.5 μm, onto stainless steel substrates. Their microstructure has been characterised via Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS) and has been reported in detail previously. Since the main application of TiN-based coatings is the enhancement of the anti-wear resistance of metallic substrates, this work is focused on the tribological performance of gradient TiAlSiN coatings under dry sliding conditions. For this purpose, tests were carried out in a ball-on-disc apparatus, using an alumina ball as counterbody. The influence of the sliding velocity on the evolution of the friction coefficient and the wear lifetime of the gradient coatings has been evaluated in comparison to those of TiN coatings of the same thickness, tested under the same experimental conditions. It was found that the gradient microstructure results in an increase of the coatings’ mean lifetime by an average factor of three.

INVESTIGATION OF SURFACE GRADIENT MICROSTRUCTURE OF SHOT PEENED S30432 STEEL BY X-RAY LINE PROFILE ANALYSIS METHOD

2016 ◽  
Vol 24 (06) ◽  
pp. 1750078 ◽  
Author(s):  
K. ZHAN ◽  
W. Q. FANG ◽  
B. ZHAO ◽  
Y. YAN ◽  
Q. FENG ◽  
...  
Keyword(s):  
Line Profile ◽  
Shot Peening ◽  
Profile Analysis ◽  
Rietveld Method ◽  
Size Variation ◽  
Domain Size ◽  
Line Profile Analysis ◽  
Analysis Method ◽  
X Ray ◽  
Gradient Microstructure

S30432 steels were processed by multistep shot peening treatment. The refined microstructures, including domain size, microstrain, domain size distribution and texture were characterized by X-ray diffraction (XRD) line profile analysis method, respectively. The results demonstrate that in the deformed layers, a gradient structure is formed after shot peening. The domain size reaches 25[Formula: see text]nm at the surface, then it decreases as the depth increases, but microstrain (0.0027) is the largest at the surface. The domain size distributions at different depths calculated by Rietveld method are consistent with domain size variation along the depth. There are no strong textures after shot peening treatment. The change of microhardness along the depth is in accordance with the gradient microstructure. It is expected that this work can offer useful information for characterizing the microstructure of shot peened materials.

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