The Formation of Cobalt Chromium Molybdenum (CoCrMo) Foams Fabricated by Slurry Method

2016 ◽  
Vol 840 ◽  
pp. 197-201
Author(s):  
Sufizar Ahmad ◽  
M. Rosli ◽  
Nur Suliani Abdul Manaf ◽  
Murni Faridah Mahammad Rafter ◽  
Fazimah Mat Noor
Keyword(s):  
Sintering Temperature ◽  
Average Pore Size ◽  
Sem Analysis ◽  
High Porosity ◽  
Sintering Process ◽  
Cobalt Chromium ◽  
Average Pore ◽  
Slurry Method ◽  
Cobalt Chromium Molybdenum ◽  
Orthopedic Applications

Cobalt Chromium Molybdenum (CoCrMo) is a metal that are widely used in the biomedical field of orthopedic applications. CoCrMo foam was developed in the form of a porous structure where it has a high porosity on the surface with the different pore sizes and shapes. This research is intended to produce CoCrMo foam by using slurry method and to study the effect of composition and sintering temperature on the metal foams. The slurry of CoCrMo was prepared by mixing the binder materials of Methylcellulose (CMC), Polyethylene Glycol (PEG) and distilled water for an hour. Followed by mixing and stirring the CoCrMo powder for another 1 hour until it becomes slurries. Polyurethane (PU) foam was then impregnated into the slurry and dried for a day in the oven with 60 °C. Sintering process is carried out at temperature of 1000 °C, 1100 °C and 1200 °C using a tube furnace. Then sample of CoCrMo foam was going through a shrinkage measurement, microstructure analysis by using Scanning Electron Microscope (SEM), analysis of element by using Energy Diffraction X-ray (EDX) and also the density and porosity test by using Archimedes method. The sample with the composition of 65wt% was the best result in this experiment. While sintering temperature of 1200 °C produced the highest number of porosities. The shrinkage percentage is from 2.67% to 14.13%. The density obtained is in between 1.538 g/cm3 and 2.706 g/cm3 while the percentage of porosity is from 50.284% to 78.934%. The average pore size is in the range of 249.63μm to 445.38μm. The best sintering temperature and composition to produced high porosity were on 1200 °C and 65wt%.

Assessing the Physical Properties of Cobalt Chromium Molybdenum (CoCrMo) Foams with Different Composition

2016 ◽  
Vol 1133 ◽  
pp. 314-318
Author(s):  
Nur Suliani Abdul Manaf ◽  
Sufizar Ahmad ◽  
Rosdi Ibrahim
Keyword(s):  
Physical Properties ◽  
Room Temperature ◽  
Bone Cells ◽  
Methyl Cellulose ◽  
Sem Analysis ◽  
Vacuum Furnace ◽  
Sintering Process ◽  
Cobalt Chromium ◽  
Polymeric Foam ◽  
Cobalt Chromium Molybdenum

Replication or slurry dipping is a simple and popular method of producing porous and interconnected foams using a metallic slurry. The advantage of the network-like metal foams is it exhibits a natural bone-like structure which enables ingrowth of bone cells and blood vessels. The aim of the present study was to investigate the physical properties of Cobalt Chromium Molybdenum (CoCrMo) foams after sintering process using vacuum furnace. The CoCrMo slurry was prepared by using different composition of CoCrMo powder which was 50wt%, 55wt%, 60wt%, 65wt% and 70wt%. The CoCrMo slurry was produced by mixing CoCrMo powder with Polyethylene Glycol (PEG), Carboxyl Methyl Cellulose (CMC) and distilled water. Then, polymeric foam template was impregnated in CoCrMo slurry and dried at room temperature. Sintering was carried out in a high temperature vacuum furnace at 1300°C. The CoCrMo foam was characterized by using a Scanning Electron Microscopy (SEM) analysis. The physical properties of CoCrMo foam was analyzed by porosity and bulk density test that was Archimedes method. From the study it was expected that the composition of metallic slurry play important roles to produce a CoCrMo foam. The best composition that obtained in this experiment was 70wt%. The porosity and density value for 70wt% of composition were 20.3% and 2.63g/cm3. The higher composition of metallic slurry will decrease the density and will increase the porosity.

scholarly journals Effect of microsilica content on microstructure and properties of foamed ceramics with needle-like mullite

2019 ◽  
Vol 13 (2) ◽  
pp. 202-209 ◽  
Author(s):  
Wenying Zhou ◽  
Wen Yan ◽  
Nan Li ◽  
Yuanbing Li ◽  
Yajie Dai ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Raw Materials ◽  
Average Pore Size ◽  
High Porosity ◽  
Sintering Process ◽  
Average Pore ◽  
Linear Change ◽  
Direct Foaming Method ◽  
Industrial Alumina

In this study, five foamed ceramics with struts containing needle-like mullite were prepared by direct-foaming method using white clay, industrial alumina and microsilica powder as raw materials. The effects of microsilica content on the phase compositions, microstructures and properties of foamed ceramics were investigated. The results showed that the adding of microsilica decreased the average pore size and apparent porosity and increased the compressive strength and thermal conductivity of the foamed ceramics by affecting the properties of foamed slurry and reaction sintering process. The foamed ceramics with 10 wt.% microsilica content showed the best properties with high porosity of 75.8%, positive reheating linear change, compressive strength of 1.44MPa and low thermal conductivity of 0.219W/(m?K) (at 350?C).

Effect of Using Different Compositions and PU Foam Template to Produce Cobalt Chromium Molybdenum (CoCrMo) Foams

2016 ◽  
Vol 840 ◽  
pp. 202-206
Author(s):  
Nur Suliani Abdul Manaf ◽  
Sufizar Ahmad ◽  
Rosdi Ibrahim
Keyword(s):  
Bone Cells ◽  
Methyl Cellulose ◽  
Sem Analysis ◽  
Vacuum Furnace ◽  
Sintering Process ◽  
Cobalt Chromium ◽  
Pu Foam ◽  
Different Types ◽  
Cobalt Chromium Molybdenum ◽  
Pu Foams

Slurry dipping is a simple and popular method of producing porous and interconnected foams using a metallic slurry. The advantage of the network-like metal foams is it exhibits a natural bone-like structure which enables ingrowth of bone cells and blood vessels. The aim of the present study was to investigate the effect of using difference composition and scaffold to produce Cobalt Chromium Molybdenum (CoCrMo) foams. The CoCrMo slurry was prepared by using different composition of CoCrMo powder which was 60wt%, 65wt% and 70wt%. Also two different types of scaffold were used in this study. The CoCrMo slurry was produced by mixing CoCrMo powder with Polyethylene Glycol (PEG), Carboxyl Methyl Cellulose (CMC) and distilled water. Then, polyurathane foam template was dipped in CoCrMo slurry and dried at room temperature. Sintering process was running by vacuum furnace at high temperature, 1200°C. The CoCrMo foam was characterized by using a Scanning Electron Microscopy (SEM) analysis. The physical properties of CoCrMo foam was analyzed by porosity and bulk density test that was Archimedes method. From the study it was expected that the composition of metallic slurry play important roles to produce a CoCrMo foam. In order to orthopaedics application to apply in cancellous bone, highest value of porosity from PU foams type (a) was most suitable result to use. This is due to the value of porosity that generate that was 65.2%.

scholarly journals Minimizing Drying Shrinkage and Enhancing Impermeability of Foam Concrete Modified with Epoxy Resin

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jianqing Gong ◽  
Ke Li
Keyword(s):  
Surface Energy ◽  
Pore Size ◽  
Epoxy Resin ◽  
Average Pore Size ◽  
Drying Shrinkage ◽  
Maximum Level ◽  
High Porosity ◽  
Foam Concrete ◽  
Average Pore ◽  
Internal Pore Structure

Relatively high drying shrinkage and permeability were two of the major challenges associated with foam concrete (FC), primarily due to its high porosity nature. This study was aimed at reducing the drying shrinkage and improving the impermeability of FC by blending and modifying it with epoxy resin (EP). Extensive laboratory testing yielded an optimum content of 4.0% EP, corresponding to a minimum drying shrinkage rate of 1.47 mm/m, which was 48% lower than that of the unmodified FC. At this optimum dosage of 4.0% EP, the permeability pressure was at a maximum level of 1.4 MPa, whereas the permeability coefficient was at its lowest value of 0.75 × 10−9  mm/h. Internal pore structure and EP distribution were characterized using the scanning electron microscopy and indicated that a microgrid structure of the FC was formed internally, featuring an increase in the number of pores, a reduction in the average pore size, and a uniform pore size distribution. Similarly, surface energy measurements using the tensiometry method yielded maximum surface energy values at 4.0% EP content, which could be used to explain the reduced drying shrinkage and the enhanced impermeability characteristics of the modified FC.

Microstructure and Mechanical Properties Study of CoCrMo Parts Sintered under Control Atmosphere

2016 ◽  
Vol 1133 ◽  
pp. 85-89
Author(s):  
Mohamad Azmirruddin Ahmad ◽  
Fazira Suriani Mohamed Fadzil ◽  
Mazlan Mohamad ◽  
Mohamad Hasnan Abdul Hamid ◽  
Mohd Asri Selamat
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Inert Gases ◽  
Cobalt Chromium ◽  
Sintered Compact ◽  
Sintering Atmosphere ◽  
Knee Replacements ◽  
Powder Pressing ◽  
Cobalt Chromium Molybdenum ◽  
Bio Compatibility

Their excellent properties, such as corrosion resistance, fatigue strength and bio-compatibility, made Cobalt-chromium-molybdenum (CoCrMo) were used in total hip and knee replacements and dental devices. The green CoCrMo compacts specimens in rectangle shape were fabricated by powder pressing technique. The effects of sintering temperature and atmosphere on the mechanical properties and microstructure of the CoCrMo compacts which is sintered at 1300°C-1400°C under two different inert gases sintering atmosphere (Ar2/N2H2) were investigated. The experimental results show that the grain boundaries sizes of CoCrMo compact sintered specimen were increased with increasing sintering temperature. The CoCrMo compacts specimens sintered at 1350°C under inert gases N2H2 atmosphere possess highest density (8.096 g/cm3) and hardness (327.1Hv). However, when the compacts specimens are sintered at 1400°C, the density (7.596 g/cm3) and hardness (320 Hv) properties of sintered compact were decreased.

Porous AlN Ceramics Fabricated by Carbothermal Reduction

2014 ◽  
Vol 788 ◽  
pp. 627-631
Author(s):  
Yuan Lu ◽  
Jing Long Li ◽  
Jian Feng Yang ◽  
Peng Li
Keyword(s):  
Mechanical Properties ◽  
Carbothermal Reduction ◽  
Glass Phase ◽  
Sintering Temperature ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
High Porosity ◽  
Sintering Additives ◽  
Fine Microstructure ◽  
Complete Formation

A new method for preparing porous AlN ceramics with high porosity had been developed by carbothermal reduction of die-pressed green bodies composed of alumina, carbon, sintering additives and AlN seeds. The influences of sintering additives and sintering temperature on the microstructure and mechanical properties of porous AlN ceramics were investigated. XRD analysis proved that complete formation of AlN phase except for minor of glass phase. SEM analysis showed that the resultant porous AlN ceramics occupied fine microstructure and a uniform pore structure. Porous AlN ceramics with a porosity of 41~66% and a strength of 2.7~ 51.8 MPa were obtained.

scholarly journals Tailoring the strength and porosity of rapid-hardening magnesia phosphate paste via the pre-foaming method

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Li-Jie Liu ◽  
Jin-Hong Li ◽  
Xiang Wang ◽  
Ting-Ting Qian ◽  
Xiao-Hui Li
Keyword(s):  
Compressive Strength ◽  
Porous Structure ◽  
Bulk Density ◽  
Sodium Silicate ◽  
Average Pore Size ◽  
Hydration Product ◽  
Polypropylene Fibers ◽  
High Porosity ◽  
Average Pore ◽  
Maximum Compressive Strength

Abstract High-porosity magnesia phosphate paste (HPMPP) was prepared via the pre-foaming method. In the pre-foaming method, sintering treatment was not required. The bulk density and maximum compressive strength of the HPMPP prepared according to the ratio of water to solids (W/So) of 0.32 reached 464.00 ± 5.00 Kg/m3 and 0.30 ± 0.05 MPa, respectively. The compressive strength increased with the increases in the addition amounts of sodium silicate and polypropylene fibers. The bulk density of HPMPP increased with the increase in the addition of sodium silicate and decreased with the increase in the addition of polypropylene fibers. Besides, the porosity of the magnesia phosphate paste increased from 79.85% to 81.27% and from 80.31% to 83.75% after the addition of sodium silicate and polypropylene fibers respectively. The highest porosity (83.75%) of the prepared HPMPP was realized under the addition proportion (sodium silicate: polypropylene fibers: solids = 0.06:0.0025:1). The average pore size of the prepared HPMPP is about 180 μm and the pore distribution range is relatively narrow. The hydration product (struvite) is combined with MgO particle one by one and then coated on the surface of bubbles. With the decrease of the water content, after breaking bubbles, the porous structure can be achieved.

Influence of Glassy Additives on the Formation of Crystalline Phases in Sintered Red Ceramic Bodies

2015 ◽  
Vol 1765 ◽  
pp. 77-82
Author(s):  
A.F. Chávez-Villanueva ◽  
G. Vargas-Gutiérrez ◽  
J. López-Cuevas ◽  
C.M. López-Badillo
Keyword(s):  
Sintering Temperature ◽  
Research Work ◽  
Soda Lime ◽  
Glass Frit ◽  
Sem Analysis ◽  
Soda Lime Glass ◽  
Nominal Composition ◽  
Sintering Process ◽  
Crystalline Phases ◽  
Floor Tiles

ABSTRACTThe main objective of this research work was to study the influence of glassy additives on the formation of crystalline phases in sintered red ceramic bodies used for the fabrication of ceramic floor tiles, whose composition is a mixture of quartz (SiO2), kaolinite [Al2Si2O5(OH)4], albite (NaAlSi3O8), muscovite [KAl2(Si3Al)O10(OH)2] and calcite (CaCO3). The additives used were: fly ash, soda-lime glass, borosilicate glass, glass frit, Na2P3O10 and cryolite (Na3AlF6). These were added in variable proportions to the nominal composition of the red ceramic bodies, either as single or as combined additions, aiming to accelerate the densification of the materials during their sintering process. For all the additive types used, the crystalline phases formed in the samples sintered using a peak temperature ranging from 950 to 1030 °C were: quartz (SiO2), anorthite (CaAl2Si2O8), and hematite (Fe2O3). It is known that the presence of anorthite is particularly beneficial for the mechanical properties, chemical stability and densification of the sintered red ceramic bodies. However, some of the considered additions tended to be detrimental for the formation of this phase in the studied materials, especially at the lowest peak sintering temperature employed. This was verified by means of XRD and SEM analysis.

scholarly journals EFFECT OF AGAR-KAOLIN INTERACTION IN GELCASTING MIXTURES ON FORMING OF ALUMINA MEMBRANE SUPPORT

2018 ◽  
Vol 80 (3-2) ◽  
Author(s):  
Kowit Lertwittayanon
Keyword(s):  
Optimum Condition ◽  
Relative Density ◽  
Pore Size ◽  
Rough Surface ◽  
Sintering Temperature ◽  
Average Pore Size ◽  
High Strength ◽  
Asymmetric Membrane ◽  
Alumina Membrane ◽  
Average Pore

Disc alumina membrane supports were formed through agar gelcasting method. The agar gelcasting was expected to be environmentally-friendly forming technique using simple equipment. Final agar amounts (0.25 – 0.75wt%) in gelcasting mixtures were varied to find the optimum condition of shaping and the desired microstructure of sintered supports. The gelcasting mixtures were prepared from non-reactive grade Al2O3 and porcelain at the ratio of 98.5:1.5 by weight. The porcelain addition allowed the membrane support to have high strength at lower sintering temperature. When the final agar amounts increased from 0.25 to 0.75wt%, the dried, gelcast supports tended to have rough surface and subsequently resulting in crack. TGA profiles confirmed that there was interaction between agar chains and kaolin particles on cooling the gelcast supports leading to different microstructures after sintering. The final agar amount of 0.5 wt% provided the highest porosity of 48.9% and the highest relative density of 61.5%. Additionally, the average pore size of 1.5 µm was obtained at the final agar amount of 0.5 wt% suitable for using as asymmetric membrane support or microfiltration membrane.   

Structural Characteristics and Mechanical Properties of Biomedical Porous Ti-10Mo Alloy Fabricated by Selective Laser Sintering

2012 ◽  
Vol 520 ◽  
pp. 234-241
Author(s):  
Fang Xia Xie ◽  
Xin Lu ◽  
Xin Bo He ◽  
Xuan Hui Qu
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Sintering Temperature ◽  
Structural Characteristics ◽  
Average Pore Size ◽  
Selective Laser Sintering ◽  
Compressive Yield Strength ◽  
Average Pore ◽  
Porous Ti ◽  
Interconnected Pores

Ti-Mo alloy is one of the most prospective metallic biomaterials for implant application because of its low elastic modulus, high corrosion resistance and tissue compatibility. A complex-shaped porous Ti-10Mo alloy from a mixture of elemental metal powders and polymer binders was processed by selective laser sintering forming, followed by thermal debinding and sintering in vacuum. The effects of processing parameters on structural characteristics and mechanical properties were studied. The results indicate that the pore characteristic parameters, matrix microstructure and mechanical properties strongly depend on the sintering temperature. Specimens sintered at 1100 °C exhibit a higher porosity of 52.41%, and possess many three-dimensionally interconnected pores with an average size of 200 μm, and the matrix is dominated by α and β phases, and meanwhile the alloy exhibits a compressive yield strength of 95.59 MPa and an elastic modulus of 4.89 GPa at room temperature. With the rise in sintering temperature, both the porosity and the average pore size of specimens gradually decrease, and the interconnected pores tend to be closed. Specimens sintered at 1400 °C are characterized by a porosity of 26.32% and an average pore size of 60 μm with a compressive yield strength of 440 MPa and an elastic modulus of 35.26 GPa.

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