Preparation and Characterization of Al-Al2O3 Metal Ceramics via Powder Metallurgy Methods

2016 ◽  
Vol 697 ◽  
pp. 350-353
Author(s):  
Da Ming Du ◽  
Rui Hua Wang ◽  
Jie Guang Song ◽  
Si Yuan Yu ◽  
Yao Qi Li ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Powder Metallurgy ◽  
Relative Density ◽  
High Performance ◽  
Sintering Temperature ◽  
Al Content ◽  
Cermet Materials ◽  
Powder Metallurgy Methods ◽  
Opposite Tendency

Metal ceramics are a important new engineering materials with the advantages of ceramics and metal materials. The Al-Al2O3 metal ceramics were prepared via the powder metallurgy methods and characterized in this paper, which lay the base for preparing the high performance cermet materials. Through the results and analysis, the conclusions are shown that the relative density is increased with a increasing forming pressure, the electrical resistivity is decreased with a increasing forming pressure. The relative density is increased with a increasing sintering temperature under 700°C, the relative density decreases with a increasing sintering temperature above 700°C, the electrical resistivity is shown the opposite tendency. Through the optimizing the technological parameter, such as the sintering temperature at 700°C, the forming pressure under 20MPa, the Al content for 75wt%, Al-Al2O3 metal ceramics are successfully prepared with the high relative density and the low electrical resistivity, the relative density is 97.52%, and the electrical resistivity is 101.34Ω·m

Effect of Molding Pressure on Densification of Al2O3/Al Cermet Materials

2017 ◽  
Vol 893 ◽  
pp. 100-104
Author(s):  
Rui Hua Wang ◽  
Xiu Qin Wang ◽  
Shuang Dong ◽  
Ning Niu ◽  
Du Juan Chang ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
High Performance ◽  
Sintering Temperature ◽  
Molding Pressure ◽  
Powder Metallurgy Method ◽  
Sample Density ◽  
Metal Materials ◽  
Engineering Materials ◽  
Cermet Materials

Cermet materials is a important new engineering materials with the advantages of ceramics and metal materials. The Al2O3/Al cermet materials is prepared via the powder metallurgy method, the effect of sintering technology on properties of Al2O3/Al cermet materials is researched in this paper, which lay the base for preparing the high performance cermet materials. The results are shown through the study, the denstity of cermet is increased with an increasing moliding pressure, the sample density is 2.084g/cm3 as the pressure for 40MPa and the sintering temperature at 600¡æ, the density is higher, that is to say it is highest performance, the distribution of aluminum and alumina is most uniform. When the sintering temperature is higher, howerver, the molding pressure is lower, the lower density of the sample is shown, the aluminum is easier to overflow the surface of the sample.

Spark Plasma Sintering and Characterization of WC-Co-cBN Composites

2014 ◽  
Vol 616 ◽  
pp. 194-198 ◽  
Author(s):  
Jian Feng Zhang ◽  
Rong Tu ◽  
Takashi Goto
Keyword(s):  
Fracture Toughness ◽  
Phase Transformation ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Moderate Pressure ◽  
Plasma Sintering ◽  
Spark Plasma

WC-Co-cBN composites were consolidated by SPS at 1373 to 1673 K under a moderate pressure of 100 MPa. The addition of cBN increased the starting and finishing temperature of shrinkage and decreased the relative density of WC-Co. The relative density of WC-(10-20 vol%) cBN composites was about 97-100% at 1573 K and decreased with increasing the sintering temperature to 1673 K due to the phase transformation of cBN to hBN. The highest hardness and fracture toughness of WC-Co-20 vol% cBN composite sintered at 1573 K were 23.2 GPa and 8.0 MP m1/2, respectively.

Preparation and characterization of low-cost high-performance mullite-quartz ceramic proppants for coal bed methane wells

2018 ◽  
Vol 25 (5) ◽  
pp. 957-961 ◽  
Author(s):  
Kaiyue Wang ◽  
Huijun Wang ◽  
Yi Zhou ◽  
Guomin Li ◽  
Yaqiao Wu ◽  
...  
Keyword(s):  
High Performance ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Low Cost ◽  
Quartz Ceramic ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Sintering Process ◽  
Flow Mechanism

AbstractIn this study, the mullite-quartz-based proppants were successfully prepared by using the coal gangue as the raw materials. Then, the effects of the additive and the sintering temperature on the composition, microstructure, and properties of the proppants were investigated. Results showed that the proppants sintered at 1250°C with the 10 wt% bauxite additive presented the best performance, which was very close to that of the quartz-proppant, and met the operational requirements of the 52 MPa coal bed methane wells. The viscous flow mechanism of the liquid phase formed during the sintering process also promoted the arrangement of the grains, thus benefiting the densification and the strength of the proppants.

Preparation and Characterization of (1-x)BiScO3-xPbTiO3 Ceramics by Two-Step Sintering

2008 ◽  
Vol 368-372 ◽  
pp. 8-10 ◽  
Author(s):  
Ting Ting Zou ◽  
Xiao Hui Wang ◽  
Long Tu Li
Keyword(s):  
Grain Size ◽  
Low Temperature ◽  
High Performance ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Sintering Aid ◽  
Potential Approach ◽  
Fine Grain ◽  
Sintering Method

High-performance fine-grain (1-x)BiScO3-xPbTiO3 ceramics were prepared by two-step sintering method. Influences of sintering temperature, holding time, and composition on the microstructure and properties were discussed. The BSPT ceramics obtained via two-step sintering reaches density higher than 95% at a low temperature of 800°C without any sintering aid, and the grain size of the ceramics is also effectively controlled. Excellent piezoelectric properties between the composition of x=0.63 and x=0.64 reveals a probable MPB in this range, suggesting a potential approach to pursue high performance BSPT ceramics.

The Effect of Sintering Temperature to the Microstructure and Properties of AZ91 Magnesium Alloy by Powder Metallurgy

2013 ◽  
Vol 377 ◽  
pp. 250-254 ◽  
Author(s):  
Ya Jun Zhou ◽  
Ai Yun Jiang ◽  
Jian Xiu Liu
Keyword(s):  
Powder Metallurgy ◽  
Magnesium Alloy ◽  
Relative Density ◽  
Volume Diffusion ◽  
Sintering Temperature ◽  
Second Phase ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium ◽  
Microstructure Of The Material ◽  
Energy Disperse Spectroscopy

AZ91 magnesium alloy was fabricated by powder metallurgy. The effects of sintering temperature on the relative density, hardness and tensile strength were investigated. The microstructure of the material was observed by scanning electron microscopy (SEM) and Energy Disperse Spectroscopy (EDS). The study found that the best sintering temperature is 550°C under the vacuum hotpressing, and at this sintering temperature the relative density can reach to 98.3%. SEM and EDS show that the sintering microstructure of the alloy is composed of α-Mg solid solution and the second phase β-Mg17Al12. Under the 550°C sintering temperature, Volume diffusion is the mainly sintering form, and produced more β-Mg17Al12 which is dispersively distributed on the grain boundary, and improves the hardness of alloy by second-phase strength.

A Novel Forming Process for Powder Metallurgy of Superalloys

2014 ◽  
Vol 622-623 ◽  
pp. 833-839 ◽  
Author(s):  
Qian Bai ◽  
Jian Guo Lin ◽  
Gao Feng Tian ◽  
Daniel S. Balint ◽  
Jin Wen Zou
Keyword(s):  
Powder Metallurgy ◽  
Relative Density ◽  
High Performance ◽  
Low Cost ◽  
Hot Isostatic Pressing ◽  
Hot Extrusion ◽  
Forming Process ◽  
Isostatic Pressing ◽  
Wide Range ◽  
Forming Temperature

Powder metallurgy (PM) of nickel-based superalloys has been used for a wide range of products owing to their excellent special properties in processing and applications. Typical processes for high performance PM superalloys include hot isostatic pressing, hot extrusion and hot isothermal forging. Hot isostatic pressing is normally conducted at a high temperature, by using a low pressure for a long time in a closed vessel, resulting in high cost and low product efficiency. In this paper a novel forming process, i.e. direct powder forging for powder metallurgy of superalloys has been proposed. In this process, the encapsulated and vacuumed powder is heated up to the forming temperature and forged directly to the final shape, by using a high forming load for a very short time. Direct powder forging is a low-cost and energy-saving process compared to conventional PM processes, and in addition, press machines of conventional forging can be used for direct powder forming process. In direct powder forging it is important to control the relative density of the deformed part since the existence of voids could reduce the mechanical strength and fatigue life. In this paper, feasibility tests of direct powder forging are presented. Microstructure, relative density and hardness of the formed specimen were studied.

Graphite/Copper Composites with High Density

2015 ◽  
Vol 723 ◽  
pp. 475-480 ◽  
Author(s):  
Yong Ping Jin ◽  
Bin Guo
Keyword(s):  
Electron Microscope ◽  
Powder Metallurgy ◽  
Relative Density ◽  
Milling Time ◽  
Sintering Temperature ◽  
Optical Microscope ◽  
Difficult Problem ◽  
Copper Compound ◽  
Technological Parameters ◽  
Scanning Electron

It is a difficult problem how to obtain the density of powder metallurgy products. Sintering billets had been prepared by mechanical milled graphite/copper compound powders firstly. Their microstructures had been analyzed by such means as scanning electron microscope (SEM) and optical microscope. Influence of technological parameters on relative density had also been investigated. The results show that sintering of non-milled powders are intensely affected by sintering temperature, contrary to mechanical milled compound powders. Hot pressed sintering under vacuum can promote densification effectively. By prolonging time, elevating temperature or pressure of hot pressed sintering, relative density of sintering billets can be increased accordingly. Under the same conditions, relative density decreases with mechanical milling time of compound powders.

Fabrication and Performance of Al-NaI Radioactive Transmutation Targets

2010 ◽  
Vol 150-151 ◽  
pp. 580-587
Author(s):  
Hui Qiang Liu ◽  
Yi Feng ◽  
Xue Bin Zhang ◽  
Bin Li ◽  
Yan Fang Zhu ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Powder Metallurgy ◽  
Energy Spectrum ◽  
Relative Density ◽  
Spectrum Analysis ◽  
Bending Strength ◽  
Aluminum Matrix ◽  
Energy Spectrum Analysis ◽  
And Performance

Al-NaI radioactive transmutation target was prepared by powder metallurgy. The existing way of the phase of target was analyzed by the application of XRD and its microstructure and morphology was observed by SEM. Then EDS was used for micro-area energy spectrum analysis and the property of target with different NaI was measured and compared. The results show that NaI is uniformly distributed within the aluminum matrix. The relative density and bending strength of transmutation targets decrease with the increasing content of NaI. The hardness and electrical resistivity of transmutation targets increase with the increasing content of NaI.

Fabrication, characterization, and in vivo biocompatibility evaluation of titanium-niobium implants

2020 ◽  
Vol 235 (1) ◽  
pp. 99-108
Author(s):  
Abdurrahman Yolun ◽  
Murat Şimşek ◽  
Mehmet Kaya ◽  
Ebru Elibol Annaç ◽  
Mustafa Köm ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Powder Metallurgy ◽  
Toxic Effect ◽  
Sintering Temperature ◽  
Transformation Temperatures ◽  
Nb Content ◽  
Orthopedic Applications ◽  
Powder Metallurgy Methods

In this study, biocompatible titanium-niobium (Ti-Nb) alloys were fabricated by using powder metallurgy methods. Physical, morphological, thermal, and mechanical analyses were performed and their in vivo compatibility was evaluated. Besides α, β, and α″ martensitic phases, α+β Widmanstätten phase due to increasing sintering temperature was seen in the microstructure of the alloys. Phase transformation temperatures of the samples decreased as Nb content increased. The ratio of Nb in the samples affected their mechanical properties. No toxic effect was observed on implanted sites. This study shows that Ti-Nb alloys can be potentially used for orthopedic applications without any toxic effects.

Thermoelectric Properties of Bismuth Telluride Based Materials Prepared by Powder Metallurgy Processing

2007 ◽  
Vol 336-338 ◽  
pp. 864-867
Author(s):  
Wei Ren ◽  
Xue Quan Liu ◽  
Xiao Lin Wang ◽  
Hong Yi Jiang
Keyword(s):  
Powder Metallurgy ◽  
Mechanical Strength ◽  
Thermoelectric Properties ◽  
Bismuth Telluride ◽  
Thermoelectric Materials ◽  
High Performance ◽  
Sintering Temperature ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

Polycrystalline samples of Bi2Te3 based alloys were prepared by powder metallurgy processing including a melting-grinding and a sintering procedure of compacted pellets. Two sintering procedures as hot-pressing and spark plasma sintering (SPS) were employed. The thermoelectric properties and mechanical strength were measured in all case. Thermoelectric properties for p-type (Bi0.25Sb0.75)2Te3 and n-type Bi2(Te0.2Se0.8)3 changed with sintering temperature in both sintering methods. Mechanical strength and relative density increase with sintering temperature in two sintering procedures. The results firmly suggest that both sintering procedures are promising to obtain high performance thermoelectric materials.

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