Sintering Parameters (sintering + parameter)

Distribution by Scientific Domains


Selected Abstracts


Spark Plasma Sintering of an Infrared-Transparent Y2O3,MgO Nanocomposite

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2010
DongTao Jiang
A novel optically transparent ceramic nanocomposite Y2O3,MgO was produced using spark plasma sintering technique. Sintering parameters was optimized to obtain fully dense material while maintaining nanoscale grain size. The sintered nanocomposite has an excellent infrared transmission as a result of small grain size and homogeneous microstructure. Postsinter annealing can significantly improve the transmission. Overly larger grain size severely degrades the transmittance. [source]


Development of a 95/5 poly(L -lactide- co -glycolide)/hydroxylapatite and ,-tricalcium phosphate scaffold as bone replacement material via selective laser sintering

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008
Rebecca Louise Simpson
Abstract 95/5 Poly(L -lactide- co -glycolide) was investigated for the role of a porous scaffold, using the selective laser sintering (SLS) fabrication process, with powder sizes of 50,125 and 125,250 ,m. SLS parameters of laser power, laser scan speed, and part bed temperature were altered and the degree of sintering was assessed by scanning electron microscope. Composites of the 125,250 ,-tricalcium phosphate (CAMCERAM® II) were sintered, and SLS settings using 40 wt % CAMCERAM® II were optimized for further tests. Polymer thermal degradation during processing led to a reduction in number and weight averaged molecular weight of 9% and 12%, respectively. Compression tests using the optimized composite sintering parameters gave a Young's modulus, yield strength, and strain at 1% strain offset of 0.13 ± 0.03 GPa, 12.06 ± 2.53 MPa, and 11.39 ± 2.60%, respectively. Porosity was found to be 46.5 ± 1.39%. CT data was used to create an SLS model of a human fourth middle phalanx and a block with designed porosity was fabricated to illustrate the process capabilities. The results have shown that this composite and fabrication method has potential in the fabrication of porous scaffolds for bone tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source]


Pressure Effect on the Homogeneity of Spark Plasma-Sintered Tungsten Carbide Powder

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2009
Salvatore Grasso
A combined experimental/numerical methodology was developed to aid full densification of pure ultrafine tungsten carbide powder by means of Spark Plasma Sintering (SPS) operating in Current Control mode. Applied pressure ranged from 5 to 80 MPa while the current intensity was set and held constant at 1400 A. The developed SPS model used a moving-mesh technique to account for the electrothermal contact resistance change during both shrinkage and punch sliding follow-up. The pressure dependence on the electrothermal contact resistance was also taken into account by the model. The experimental and numerical results showed the effects of pressure on grain growth, residual porosity, and hardness observed along the sample radius. Upon increasing sintering pressure, complete densification was obtained by reducing the peak temperature measured at the die surface. By combining experimental and modeling results, a direct correlation between compact microstructure homogeneity and sintering parameters (i.e., temperature and applied pressure) was established. [source]


Differential Sintering by Improper Selection of Sintering Parameters during Pulse Electric Current Sintering

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2004
D. Doni Jayaseelan
Recently, we reported on the retention of fine-grained micro-structure in Al2O3/3 vol% 3Y-ZrO2 composites using the pulse electric current sintering (PECS) technique. It was demonstrated that a high heating rate is beneficial for the retention of fine grains and homogeneous microstructure. As there are few reports on microstructural inhomogeneity and excessive grain growth in compacts densified by the PECS technique, we carried out a series of experiments on monolithic alumina by varying the sintering parameters and discussed the characteristic results. All specimens that were densified under selective sintering conditions attained high density (,99% of the theoretical density) at 1250°3C in > 5 min. The average fracture strength of monolithic alumina was observed to be 741 ± 25 MPa and the fracture toughness was 2.2 MPa.m <1/2, and these were reasoned out to small grains. However, compacts sintered under very low compaction pressure attained ,92%-93% of the theoretical density, and these specimens had undesirable microstructural inhomogeneity owing to differential sintering. Hence, in the present study, we address the problem of differential sintering. [source]