Modeling the Densification of FeSi Sintered Magnetic Alloys

2012 ◽  
Vol 727-728 ◽  
pp. 175-180 ◽  
Author(s):  
José Adilson de Castro ◽  
Gilberto V. Concilio ◽  
Daniel Rodrigues ◽  
Livia S. Santomauro ◽  
Marcos Flavio de Campos
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Sintering Temperature ◽  
Process Parameter ◽  
Model Parameters ◽  
Important Process ◽  
Sintering Process ◽  
Heating Rates ◽  
Magnetic Alloys ◽  
Sintered Alloys

An important process parameter in FeSi sintered alloys is the sintering temperature. If the sintering temperature can be reduced, the sintering process could be performed in less expensive furnaces. A densification model is here applied to experimental data. The model considers both grain size and density. After the model is applied to experimental data, the acquired model parameters allow the simulation of densification for other situations of temperature and heating rates. The model can be helpful to find suitable sintering temperatures in these alloys.

Modeling the Densification of 316L Stainless Steels

2012 ◽  
Vol 727-728 ◽  
pp. 440-445 ◽  
Author(s):  
José Adilson de Castro ◽  
Nelson Karsokas Filho ◽  
Daniel Rodrigues ◽  
Marcos Flavio de Campos
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Size Distribution ◽  
Stainless Steels ◽  
Heating Rates ◽  
Austenitic Alloy ◽  
Sintering Conditions

Stainless steels are employed as filters, and in this application the amount of pores and their size distribution are very important. Here it is discussed a densification model, which takes into account both, grain size and density. After this model is applied to experimental data, the obtained parameters can be used for extrapolation in other sintering conditions, for example other temperatures and heating rates. The studied material is the austenitic alloy 316L.

scholarly journals Influence of sintering temperature on raw and beneficiated clay “Klokoti”

2012 ◽  
Vol 44 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Marina Jovanovic ◽  
Tatjana Volkov-Husovic
Keyword(s):  
Grain Size ◽  
Chemical Composition ◽  
Glassy Phase ◽  
Sintering Temperature ◽  
Phase Content ◽  
Sintering Process ◽  
Characteristic Temperatures ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Scanning Electron

The raw clay ?Klokoti? from middle Bosnia was beneficiated by method of wet separation which results in removing fraction over 20 ?m. The raw clay was characterized by chemical composition, grain size distribution and characteristic temperatures on heating microscope. The beneficiated clay was characterized by chemical composition and characteristic temperatures. The phase composition of raw and beneficiated clay was observed by RDA while the microstructure was monitored on scanning electron microscope (SEM). The sintering process was performed at 1100?C, 1250?C, 1320?C and 1400?C with two hours holding time at the highest temperature. The obtained results indicate a big content of coarse quartz in raw clay and gradually increase of crystalline mullite content with increasing temperature of sintering. Beneficiated clay at higher temperature of sintering produces larger glassy phase content, which is result of larger fluxing content in its composition. It is also observed that from beneficiated clay by sintering at 1250?C crystallize the most mullite along with minimum porosity and the lowest glassy phase content.

Microstructure and Luminance Properties of Integrated Translucent Alumina Tube Used in Metal Halide Lamps

2010 ◽  
Vol 177 ◽  
pp. 272-276
Author(s):  
Liu Feng ◽  
Zhi Wei Chen ◽  
Jin Ye Niu
Keyword(s):  
Grain Size ◽  
Surface Finish ◽  
Sintering Temperature ◽  
Metal Halide ◽  
Alumina Tube ◽  
Sintering Process ◽  
Micro Structure ◽  
Average Grain Size ◽  
Gelcasting Process ◽  
Metal Halide Lamps

The integrated translucent alumina tube used in metal halide lamps have been fabricated by gelcasting process. The influence of sintering process, various sintering fluxes on the micro- structure was discussed. Furthermore, the relation between the luminance and the microstructure was also investigated. The results reveal that when the sintering temperature is 1750°C, the holding time is 6h, the compact product whose average grain size is about 20μm could be obtained; the triple dopant combinations of MgO, Y2O3, La2O3 can promote sintering and improve the microstructure more than double, single dopants and the contents of sintering flux are 99.6wt%Al2O3, 0.2wt%MgO, 0.1wt.%Y2O3 and 0.1wt.%La2O3 respectively; The transmittance increases with the pore decreaseing, the grain size enlarging and the degree of the surface finish improving, the average in line transmittance is about 40%.

Relationships between Processing Parameters and Properties of PZT Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 57-60
Author(s):  
C. Puchmark ◽  
Gobwute Rujijanagul
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Lead Zirconate Titanate ◽  
Sintering Temperature ◽  
Processing Parameters ◽  
Lead Zirconate ◽  
Growth Equation ◽  
Sintering Process ◽  
Pzt Ceramics ◽  
Linear Fit

In present work, lead zirconate titanate (PZT) ceramics, having the composition near morphotropic phase boundary were prepared by conventional mixed oxide method. The sintering process was performed at various sintering temperatures ranging from 1100 to 1300 oC. Relationships between phase and sintering temperature, and phase and structure were reported. An increase sintering temperature affected the increase in grain size. The grain growth rate was found to have a linear fit with the phenomenological kinetic grain growth equation. Tetragonal relative fraction increased with increasing sintering temperature. In addition, dielectric constant at dielectric peak increased with increasing grain size which consistent with the trend of tetragonality.

Fabrication and Electrical Property of SiC-AlN Composites

2007 ◽  
Vol 561-565 ◽  
pp. 607-611 ◽  
Author(s):  
Junichi Hojo ◽  
Yuki Nonaka ◽  
Kai Kamada ◽  
Naoya Enomoto ◽  
Mikinori Hotta ◽  
...  
Keyword(s):  
Solid Solution ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Electrical Property ◽  
Sintering Temperature ◽  
Molar Ratio ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Wide Compositional Range

SiC and AlN form a solid solution in the wide compositional range, expectantly leading to control of the semiconductive property. In the present work, the SiC-AlN composites were fabricated by sintering process, and evaluated with emphasis on the distribution of SiC and AlN and electrical property. SiC and AlN powders were mixed at a molar ratio between 90:10 and 10:90, and sintered at 1900-2100 °C for 30 min under 50 MPa in Ar atmosphere by spark plasma sintering technique. The sintered bodies reached high densities over 95 % of theoretical, and the grain size increased with an increase in the sintering temperature and the AlN content. The SiC-AlN composites had 3C and 2H phases in SiC-rich composition, while 2H phase only in AlN-rich composition, and the mutual dissolution between SiC and AlN was enhanced at high temperatures. The electrical conductivity decreased with dissolution of AlN into SiC because of the increase in band gap.

Sintering Behavior of Ceramic Green Body by Thermal Analysis Techniques

2010 ◽  
Vol 177 ◽  
pp. 226-230 ◽  
Author(s):  
Hai Qiu Zhou ◽  
Han Ning Xiao ◽  
Xue Yan Hu
Keyword(s):  
Thermal Analysis ◽  
Sintering Temperature ◽  
Phase Changes ◽  
Sintering Behavior ◽  
Green Body ◽  
Sintering Process ◽  
Heating Rates ◽  
Analysis Techniques ◽  
Analysis Technique ◽  
Thermal Analysis Techniques

A series of physical and chemical changes, including the shrinkage and the phase transformation, will continuously take place during the sintering process of ceramic green body, which is important for designing a scientific and economic sintering schedule. The sintering behavior of two electrical porcelains and a structural tile were investigated using thermal analysis techniques. The dehydration, phase changes and densification of ceramic green body during sintering process were characterized by DSC-TG and thermal expansion curves. The sintering temperature range of ceramic green body was measured by thermal dilatometer with different heating rates. The sintering temperature Ts is linear to the logarithm of heating rate V. The results were compared with that measured by conventional refractoriness tester. The Ts is much more accurate to evaluate the sintering behavior of ceramic green body from the thermal analysis technique than that from the traditional method. The projected sintering schedule is very concordant to the experimental sintering results.

Rapid Consolidation of Nanophase Al2O3 and an Al2O3/Al2TiO5 Composite

1996 ◽  
Vol 457 ◽  
Author(s):  
David A. West ◽  
Rajiv S. Mishra ◽  
Amiya K. Mukherjee
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Powder Compact ◽  
Single Phase ◽  
Rapid Heating ◽  
Resistance Heating ◽  
Sintering Process ◽  
Heating Rates ◽  
Dc Voltage ◽  
Rapid Heating Rate

ABSTRACTA rapid consolidation technique has been utilized in producing single phase AI2O3 in less than 10 minutes at 1400°C resulting in a grain size less than 500 nm. TiO2 has been added in hopes of obtaining Al2O3/Al2TiO5 nanocomposites in sintering times less than 30 minutes. The sintering process involves resistance heating of a graphite die containing the powder at heating rates of about 10 °C/s. The resistance heating step is preceded by a preparatory step consisting of DC voltage pulses applied across a prepressed powder compact. The retention of the nanostructure is attributed to the rapid heating rate although the possible effect of the DC pulses are also discussed. An Al2O3/Al2TiO5 composite has been produced during a short anneal immediately following sintering of an Al2O3/TiO2 nanocomposite. Substantial grain growth has been observed to occur during the transformation taking the composite to the microcrystalline regime.

Mechanical Properties of Copper Hollow Sphere Manufactured by Sintering Process

2006 ◽  
Vol 510-511 ◽  
pp. 730-733 ◽  
Author(s):  
Ja Myeong Koo ◽  
Seung Boo Jung
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Compression Strength ◽  
Hollow Sphere ◽  
Sintering Temperature ◽  
Hollow Spheres ◽  
Hydrogen Atmosphere ◽  
Sintering Process ◽  
Polystyrene Spheres

The polystyrene spheres coated with a slurry, consisting of copper (I) oxide powder, water and PA (poly acrilamide), were reduced to form copper (Cu) hollow spheres at sintering temperatures ranging from 650 to 950 °C under a hydrogen atmosphere. The microstructural evolutions and mechanical properties of the Cu hollow spheres were investigated with the sintering temperature. The increase in the sintering temperature led to the increase in the density and grain size of the spheres. The amount of the residual copper oxide in the samples decreased with increasing sintering temperature. The electrical conductivity, hardness, and compression strength of the hollow spheres increased with increasing sintering temperature.

Parameter Determination for Chloride and Tritium Transport in Undisturbed Lysimeters during Steady Flow

1992 ◽  
Vol 23 (2) ◽  
pp. 89-104 ◽  
Author(s):  
Ole H. Jacobsen ◽  
Feike J. Leij ◽  
Martinus Th. van Genuchten
Keyword(s):  
Experimental Data ◽  
Unsaturated Flow ◽  
Transport Model ◽  
Time Moment ◽  
Breakthrough Curves ◽  
Coarse Sand ◽  
Retardation Factor ◽  
Parameter Determination ◽  
Model Parameters ◽  
Water Fraction

Breakthrough curves of Cl and 3H2O were obtained during steady unsaturated flow in five lysimeters containing an undisturbed coarse sand (Orthic Haplohumod). The experimental data were analyzed in terms of the classical two-parameter convection-dispersion equation and a four-parameter two-region type physical nonequilibrium solute transport model. Model parameters were obtained by both curve fitting and time moment analysis. The four-parameter model provided a much better fit to the data for three soil columns, but performed only slightly better for the two remaining columns. The retardation factor for Cl was about 10 % less than for 3H2O, indicating some anion exclusion. For the four-parameter model the average immobile water fraction was 0.14 and the Peclet numbers of the mobile region varied between 50 and 200. Time moments analysis proved to be a useful tool for quantifying the break through curve (BTC) although the moments were found to be sensitive to experimental scattering in the measured data at larger times. Also, fitted parameters described the experimental data better than moment generated parameter values.

Researches Concerning the Phenomena at the Interface for the Sintered Compacts of Titan-Hydroxyapatite

2013 ◽  
Vol 856 ◽  
pp. 164-168 ◽  
Author(s):  
Diana Irinel Băilă
Keyword(s):  
Specific Surface ◽  
Bone Tissue ◽  
Contact Zone ◽  
Cellular Differentiation ◽  
Selective Laser Sintering ◽  
Important Process ◽  
Sintering Process ◽  
Cellular Processes ◽  
Hydroxyapatite Powder ◽  
Ti Powder

The behaviour of metallic powders is very important for manufacturing parts and for realize the prototypes. Manufacturing of the orthopaedic implants by selective laser sintering process can be used in medicine. The powders necessary for SLS process are biomaterials who must assure a good osteointegration of endobone implants like the Ti powder (Ti-6Al-4V) and the hydroxyapatite powder. The conditioned powders is a very important process and is necessary in SLS to obtain medical prothesis and influence the final properties of prothesis. Materials must present a gradient for porosity and one for composition (presents of a bioactive phase in titan matrix). The exterior porosity, in the contact zones with the bone tissue, favors the incipient cellular processes (the adhesion and attachment of osteoblastes, proliferation and cellular differentiation and nucleation of mineral bone). The pores must be open and with a specific surface more great. Its preferred the exterior intercommunicating porosity. The presence of phosphates of calcium in the contact zone of the implant with bone favors the mineral kernel on bone. The report Ca/P of phosphates mineral bone has an ascending evolution towards 10/6 according to hydroxyapatite.

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