Fabrication of Zirconia Coatings using Electrophoretic Deposition and Reactive Sintering

2002 ◽  
Vol 750 ◽  
Author(s):  
Ying Yuan ◽  
Xin Wang ◽  
Ping Xiao
Keyword(s):  
Particle Size ◽  
Thermal Treatment ◽  
Electrophoretic Deposition ◽  
Powder Mixture ◽  
Milling Time ◽  
Composite Coatings ◽  
Thermal Analyses ◽  
Reactive Sintering ◽  
Attrition Milling ◽  
Al Composite

ABSTRACTElectrophoretic deposition (EPD) technique has been used to fabricate green YSZ/Al composite coatings with controlled thickness and morphology. Such green coating was transformed into the YSZ/Al2O3 composite coating during following thermal treatment in air at temperatures up to 1200°C. Suspension for EPD was prepared by attrition-milling a mixture of yttria -stabilised zirconia (YSZ) and aluminium (Al) in acetyl-acetone (ACAC). The attrition milling reduced the particle size of the powder mixture. A mechanical alloying behaviour is believed to control the agglomeration and the breaking of large Al particles. Attrition milling also reduced the YSZ crystallite size, which can be attributed to the chemical reaction between YSZ/Al particles and ACAC. Thermal analyses and dilatometry measurements of the green compact indicate the temperature range for oxidation of Al and its effect on sintering of the coating. The coating obtained from EPD in the suspension after a longer milling time was found to have more uniform in microstructure.

Study of YSZ/Al2O3 Composite Coatings Produced by Electrophoretic Deposition

2012 ◽  
Vol 538-541 ◽  
pp. 386-390
Author(s):  
Xiao Juan Lu
Keyword(s):  
Mechanical Properties ◽  
Milling Time ◽  
Particle Distribution ◽  
Composite Coatings ◽  
Deposition Process ◽  
Gradient Structure ◽  
Constraint Effect ◽  
Attrition Milling ◽  
Al2o3 Composite ◽  
Different Temperatures

YSZ/Al2O3 composite coatings have been fabricated by using EPD. The microstructures, mechanical properties and micro-stresses of the coatings produced from different sized powders and sintered at different temperatures have been studied. Different attrition milling time leads to different particle distribution modes, thereby different microstructures. Due to the deposition process and the constraint effect from the substrate, a gradient structure has been formed across the coating thickness.

Research of the Milling Time Influence on Ag-Cu Powder Particles Size Processed by Mechanical Alloying Route

2012 ◽  
Vol 188 ◽  
pp. 382-387 ◽  
Author(s):  
Oana Gîngu ◽  
Claudiu Nicolicescu ◽  
Gabriela Sima
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Mechanical Alloying ◽  
Size Distribution ◽  
Powder Mixture ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
Future Research ◽  
Powder Particles

This research focuses on Ag-Cu powder particles processing by mechanical alloying (MA) route. The powder mixture is representative for the eutectic composition, respectively 72%wt. Ag + 28% wt. Cu. The milling process is developed in high energy ball mill Pulverisette 6, using different size for the milling balls, in wet conditions for 80 hours. One of the most important parameter studied in this research is the particle size distribution of the processed powder mixture. Thus, it changes along the milling time, from 10…75 µm at the beginning of MA process up to (60 – 80) nm at 80 h. The milling parameters will be optimized in future research depending on the particle size distribution related with thermophysical and thermodynamic properties focused on electrical and optical properties improvement.

Fabrication of MoSi2 Nanocrystal by Mechanical Alloying Large Particle-Sized Starting Powders

2010 ◽  
Vol 434-435 ◽  
pp. 768-770
Author(s):  
Jun Ting Luo
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Mechanical Alloying ◽  
Powder Mixture ◽  
Large Particle ◽  
Milling Time ◽  
Average Grain Size

The MoSi2 nanocrystal was prepared by mechanical alloying (MA) large particle-sized starting powders, in which the milling time is much longer than usual MA time. It was found that the Mo-Si powder mixture mixed at stoichiometry proportion forms α-MoSi2 and β-MoSi2 in the MDR mode rather than pure α-MoSi2 in the SHS mode. The grain size of MoSi2, calculated using Scherrer′s formula, is 18nm when milled for 96h, and decreases to 12nm when further milling to 144 h. This is because that the milling balls provide enough energy to refine most of the rough crystal grain. The average grain size increased to 15nm when milled for 192 h, which indicates that further expand time could not refine the crystal grain while cause the growth of a part of the crystal grain. The particle size of MoSi2 is about 0.5μm when milled for 96 h and the agglomerating phenomenon is severe. The particle size of MoSi2 decreases to 0.4μm and releases the agglomerating phenomenon with the milling time for 144 h.

Biocompatible Ceramic-Biopolymer Coatings Obtained by Electrophoretic Deposition on Electron Beam Structured Titanium Alloy Surfaces

2016 ◽  
Vol 879 ◽  
pp. 1552-1557
Author(s):  
C. Ramskogler ◽  
L. Cordero ◽  
Fernando Warchomicka ◽  
A.R. Boccaccini ◽  
Christof Sommitsch
Keyword(s):  
Titanium Alloy ◽  
Surface Modification ◽  
Electron Beam ◽  
Electrophoretic Deposition ◽  
Composite Coatings ◽  
Substrate Surface ◽  
3D Structure ◽  
Titania Nanoparticles ◽  
Structured Surfaces ◽  
Major Interest

An area of major interest in biomedical engineering is currently the development of improved materials for medical implants. Research efforts are being focused on the investigation of surface modification methods for metallic prostheses due to the fundamental bioinert character of these materials and the possible ion release from their surfaces, which could potentially induce the interfacial loosening of devices after implantation. Electron beam (EB) structuring is a novel technique to control the surface topography in metals. Electrophoretic deposition (EPD) offers the feasibility to deposit at room temperature a variety of materials on conductive substrates from colloidal suspensions under electric fields. In this work single layers of chitosan composite coatings containing titania nanoparticles (n-TiO2) were deposit by EPD on electron beam (EB) structured Ti6Al4V titanium alloy. Surface structures were designed following different criteria in order to develop specific topography on the Ti6Al4V substrate. n-TiO2 particles were used as a model particle in order to demonstrate the versatility of the proposed technique for achieving homogenous chitosan based coatings on structured surfaces. A linear relation between EPD time and deposition yield on different patterned Ti6Al4V surfaces was determined under constant voltage conditions, obtaining homogeneous EPD coatings which replicate the 3D structure (pattern) of the substrate surface. The present results show that a combination of both techniques can be considered a promising surface modification approach for metallic implants, which should lead to improved interaction between the implant surface and the biological environment for orthopaedic applications.

A comparison of signal suppression and particle size distributions for ns- and fs-LA of metallic samples by LA-ETV-ICPMS

2017 ◽  
Vol 32 (10) ◽  
pp. 1980-1987
Author(s):  
Hale Ceren Yilmaz ◽  
Bodo Hattendorf
Keyword(s):  
Particle Size ◽  
Thermal Treatment ◽  
Graphite Furnace ◽  
Size Distributions ◽  
Electrothermal Vaporization ◽  
Particle Size Distributions ◽  
Signal Suppression

The influence of thermal treatment of laser-generated aerosols in a graphite furnace electrothermal vaporization (ETV) unit was investigated.

Preparation of Hydroxyapatite/Chitosan Biological Coatings on Carbon/Carbon Composites

2010 ◽  
Vol 434-435 ◽  
pp. 502-505
Author(s):  
Ying Hua Li ◽  
Li Yun Cao ◽  
Jian Feng Huang ◽  
Xie Rong Zeng
Keyword(s):  
Heat Treatment ◽  
Electrophoretic Deposition ◽  
Isopropyl Alcohol ◽  
Raw Materials ◽  
Composite Coatings ◽  
Thermal Conditions ◽  
Hydrothermal Condition ◽  
Subsequent Heat Treatment ◽  
Carbon Composites ◽  
Deposition Voltage

Hydroxyapatite/Chitosan (HAp/CS) bio-coatings were prepared on the surface of carbon/ carbon (C/C) composites by hydrothermal electrophoretic deposition, using sonochemical process resulted HAp nanoparticles, isopropyl alcohol and chitosan as raw materials. The influences of hydro- thermal conditions and deposition voltage on the microstructures and morphologies of the as-prepared coatings were investigated. It was shown that homogenous and dense HAp/CS coatings on C/C composites are obtained by hydrothermal electrophoretic deposition. With the increase of deposition voltage, density and homogeneity of the as-prepared HAp/CS composite coatings are well improved. Due to the growth of HAp nanoparticles in the hydrothermal condition, the subsequent heat treatment of the HAp/CS coatings is not needed.

Intermetallic Effects on the Ductility of Sintered Aluminium

2008 ◽  
Vol 587-588 ◽  
pp. 380-384
Author(s):  
Jesus Cintas ◽  
José A. Rodríguez ◽  
Francicso Gomez Cuevas ◽  
José M. Gallardo
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Intermetallic Particle ◽  
Quantitative Metallography ◽  
Mechanically Alloyed ◽  
Aluminium Powder ◽  
Attrition Milling ◽  
Different Temperatures ◽  
Alloyed Aluminium ◽  
Milled Powders

Mechanically alloyed aluminium powder was prepared by attrition-milling for 10 hours in the presence of a wax. Milled powders were annealed in vacuum at different temperatures (500, 575, 600, 625 and 650°C). Compacts were consolidated starting from unannealed and from 600°Cannealed powders. Studies by SEM microfractography and quantitative metallography, to investigate the influence of Fe-Al intermetallics on compacts fracture, have been carried out. It is concluded that fracture takes place at regions where the area occupied by the intermetallics is high and intermetallics particles are big. Intermetallic particle size can be controlled by an appropriated heat treatment.

Effect of the particle size of nanosilica on the performance of epoxy/silica composite coatings

2005 ◽  
Vol 40 (15) ◽  
pp. 3927-3932 ◽  
Author(s):  
Junjie Yuan ◽  
Shuxue Zhou ◽  
Guangxin Gu ◽  
Limin Wu
Keyword(s):  
Particle Size ◽  
Composite Coatings ◽  
Silica Composite
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