Effect of Binder Content on the Slip Rheology and Green Properties of Slip Cast Alumina

2019 ◽  
Vol 798 ◽  
pp. 177-181
Author(s):  
Kritkaew Somton ◽  
Pitak Laoratanakul ◽  
Ryan McCuiston
Keyword(s):  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
Casting Process ◽  
Binder Content ◽  
Green Density ◽  
Optimal Amount ◽  
Solids Loading ◽  
Maximum Value ◽  
Slip Cast ◽  
Scanning Electron

The rheology of A96% alumina slips and the physical and mechanical properties of slip cast samples were studied. The slips had a constant solids loading of 40 wt% alumina and a polyvinyl alcohol (PVA) content of 0-3 wt%, as a binder. The rheological behavior and viscosity of the slips were examined to determine the flowability of the slips necessary for the casting process. The slips were prepared by ball milling and the bend bar samples were cast in plaster molds. The green densities and the flexural strength of the bars were measured, and the fracture surfaces were examined by scanning electron microscopy. It was found that the slip viscosity increased with an increase of PVA content. The green flexural strength also increased to a maximum value of 0.52 MPa with increasing PVA up to 2 wt%. The further addition of PVA decreased the flexural strength. The green density did not significantly change with the PVA content, however the samples produced using 3 wt% PVA showed the lowest percentage of theoretical density of 41%. The fracture surface of the 3 wt% PVA sample showed numerous large pores compared with the other samples. Therefore, in this study it was concluded that there is in optimal amount of PVA to produce the highest green density and flexural strength of cast samples. Excess PVA reduced the flowability of the slip and resulted in excess porosity, which decreased the green density and deteriorated the flexural strength.

Flexural Strength of Superfine Grained Si2N2O-Si3N4 Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1477-1480
Author(s):  
Jun Ting Luo ◽  
Qing Zhang ◽  
Kai Feng Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Liquid Phase Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value ◽  
Average Grain Size ◽  
Main Fracture ◽  
Scanning Electron

The Si3N4- Si2N2O composites were fabricated with amorphous nano-sized silicon nitride powders by the liquid phase sintering(LPS) method. The sintering temperatures ranged from 1500°C to 1700°C. Microstructure and component of the composites were performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results show that sintered body consists of Si2N2O and β-Si3N4, with an average grain size about 1μm. The maximum value of flexural strength of the material is 680MPa when sintered at 1700°C. Transcrystalline cracking is the main fracture mechanism of the composites.

Preparation of SiCw/Al2O3 Composite Sheets through Gel-Tape-Casting Process

2011 ◽  
Vol 675-677 ◽  
pp. 119-122 ◽  
Author(s):  
Shao Chun Li ◽  
Peng Zhang ◽  
Tie Jun Zhao ◽  
Zu Quan Jin ◽  
Song Gao
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Milling Time ◽  
Tape Casting ◽  
Casting Process ◽  
Composite Tape ◽  
Solids Loading ◽  
Al2o3 Composite ◽  
Green Sheet ◽  
Ball Milling Time

In this paper, the gel-tape-casting process was applied to manufacture multilayer green sheets of SiCw /Al2O3 composite. The influence of SiCw, ball milling time and solids loading on the rheological behaviors of SiCw/Al2O3 slurries were investigated. It was found that the slurries exhibited a shear thinning behavior. The viscosity of the slurry increased with increasing of the fraction of SiCw. A stable slurry with 40 vol.% solids loading was prepared when 20 vol.% of SiCw was added. The flexural strength of the green sheet showed a trend of increasing firstly and then decreasing with SiCw increasing. The optimal mechanical properties of 40.2 MPa for flexural strength was obtained when SiCw contents was 20 vol.%. SEM observation indicated that significant whisker alignment was present in the composite tape, which was considered as one of parameters affecting toughening process.

The Effect of Temperature Fluctuation on the Formation of Billet Surface Defect in the Initial Solidification Area

2010 ◽  
Vol 148-149 ◽  
pp. 163-167
Author(s):  
Xiao Li Jin ◽  
Zuo Sheng Lei ◽  
Kang Deng ◽  
Zhong Ming Ren
Keyword(s):  
Continuous Casting ◽  
Temperature Fluctuation ◽  
Surface Defects ◽  
Casting Process ◽  
Effect Of Temperature ◽  
Billet Surface ◽  
Maximum Value ◽  
Key Factor ◽  
Oscillation Marks ◽  
Initial Solidification

The heat transfer in steel continuous casting process under mold oscillation was calculated, and temperature fluctuation phenomena was found in the initial solidification area, the maximum value was approximate 16 °C. The effect of different continuous casting parameters on temperature fluctuation were analyzed, and the temperature fluctuation was considered to be a key factor to the formation of oscillation marks. The Index of Temperature Fluctuation(ITF) was proposed to predict the effect of temperature fluctuation on the formation of billet surface defects.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

scholarly journals Properties of High-Strength Flowable Mortar Reinforced with Palm Fibers

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Test Results ◽  
Palm Fiber ◽  
Toughness Index ◽  
Strength And Toughness

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.

scholarly journals Effect of microwave disinfection on physical and mechanical properties of acrylic resins

2008 ◽  
Vol 19 (4) ◽  
pp. 348-353 ◽  
Author(s):  
Rafael Leonardo Xediek Consant ◽  
Erica Brenoe Vieira ◽  
Marcelo Ferraz Mesquita ◽  
Wilson Batista Mendes ◽  
João Neudenir Arioli-Filho
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Physical And Mechanical Properties ◽  
Hardness Test ◽  
Knoop Hardness ◽  
Microwave Energy ◽  
Bending Test ◽  
Acrylic Resins ◽  
Strength Tests ◽  
The Impact

This study evaluated the effect of microwave energy on the hardness, impact strength and flexural strength of the Clássico, Onda-Cryl and QC-20 acrylic resins. Aluminum die were embedded in metallic or plastic flasks with type III dental stone, in accordance with the traditional packing technique. A mixing powder/liquid ratio was used according to the manufacturer's instructions. After polymerization in water batch at 74ºC for 9 h, boiling water for 20 min or microwave energy at 900 W for 10 min, the specimens were deflasked after flask cooling at room temperature, and submitted to finishing. Specimens non-disinfected and disinfected by microwave irradiation were submitted to hardness, impact and flexural strength tests. Each specimen was immersed in distilled water and disinfected in a microwave oven calibrated to 650 W for 3 min. Knoop hardness test was performed with 25 g load for 10 s, impact test was carried out using the Charpy system with 40 kpcm, and 3-point bending test with a crosshead speed of 0.5 mm/min until fracture. Data were submitted to statistical analysis by ANOVA and Tukey's test (?=0.05). Disinfection by microwave energy decreased the hardness of Clássico and Onda-Cryl acrylic resins, but no effect was observed on the impact and flexural strength of all tested resins.

Effect of Filler Compositions on the Mechanical Properties of Bamboo Filled Polyester Composite

2014 ◽  
Vol 879 ◽  
pp. 90-95 ◽  
Author(s):  
Abdul Rahman Noor Leha ◽  
Nor Amalina Nordin
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Impact Test ◽  
Compression Molding ◽  
Engineering Applications ◽  
Maximum Value ◽  
Polyester Composite ◽  
Bamboo Powder ◽  
Flexural Tests ◽  
The Impact

Biocomposite from bamboo powder was fabricated by compression molding technique. The objective of this study was to investigate the mechanical properties of bamboo compounded with epoxy with different ratio. Tensile and flexural tests were done to characterize its mechanical properties. It was observed that the strength of bamboo-polyester was increased with increasing amount of bamboo powder. The tensile and flexural strength shows the highest value at 25 wt.% bamboo. However, the impact test shows the maximum value at 20 wt.% bamboo powder. These results exhibit the bamboo-polyester can be a good candidate to be used in many engineering applications

scholarly journals COMPARING THE FLEXURAL STRENGTH OF CONCRETE MADE WITH RIVER SAND WITH THAT MADE WITH QUARRY DUST AS FINE AGGREGATE

2018 ◽  
Vol 6 (6) ◽  
pp. 453-460
Author(s):  
Chijioke C ◽  
Nwaiwu ◽  
Aginam ◽  
Anyadiegwu
Keyword(s):  
Flexural Strength ◽  
Concrete Beams ◽  
Target Strength ◽  
Fine Aggregate ◽  
River Sand ◽  
Minimum Value ◽  
Maximum Value ◽  
Quarry Dust ◽  
Good Substitute

This work focuses on the 100% replacement of river sand with quarry dust in the production of concrete. Two types of concrete were produced (concrete made with river sand and that made with quarry dust as fine aggregate), the concretes produces were cast into beams and cured for 28 days. The flexural strengths of the concrete beams cast was determine at 28 day strength. At 28 days target strength the maximum flexural strength of concrete made with river sand as fine aggregate is 5.375111N/mm2 and minimum flexural strength is 2.2155N/mm2, for the concrete made with quarry dust as fine aggregate the maximum flexural strength is 2.567 N/mm2. The maximum value of 2.567 N/mm2 for concrete made with quarry dust as fine aggregate is higher than the minimum value of 2.2155N/mm2 for concrete made with river sand as fine aggregate. With this result it shows that quarry dust is a good substitute to river sand in the production of concrete.

scholarly journals Prosthetic laboratory influence on the vertical misfit at the implant/UCLA abutment interface

2007 ◽  
Vol 18 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Gustavo Augusto Seabra Barbosa ◽  
Paulo Cézar Simamoto Júnior ◽  
Alfredo Júlio Fernandes Neto ◽  
Maria da Glória Chiarello de Mattos ◽  
Flávio Domingues das Neves
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Casting Process ◽  
Significant Difference ◽  
Scanning Electron

An inadequate fit at the abutment/implant interface can generate mechanical and biological problems. The laboratorial stages could induce misfit in such interface when the castable UCLA abutment type is used. The purpose of this study was to comparatively evaluate the performance of three prosthetic laboratories (Labs A, B and C) by vertical fit analysis of castable UCLA abutments on the casting and soldering stages of the same prosthesis. Four fixed prostheses were built by each laboratory using castable UCLA abutments. The evaluation was made by scanning electron microscopy under 500x magnification in the mesial and distal regions of each element of the prosthesis, totalizing 24 measurements per laboratory. The results were analyzed statistically by Kruskal-Wallis test (p<0.05). In the casting process, the values presented by the laboratories differed significantly to each other (p=0.004). After soldering, the values presented by the laboratories showed no significant difference (p=0.948). It may be concluded that the fit values obtained in the casting stage of UCLA abutments can be influenced when processed by different laboratories, and that conventional soldering itself increased the degree of framework misfit, regardless of which laboratory made it.

Comparison of Different Alumina Powders for Aqueous Tape Casting Process

2015 ◽  
Vol 820 ◽  
pp. 172-177
Author(s):  
Fernanda P. Santos ◽  
Ediana Gambin ◽  
Cristina Moniz A. Lopes ◽  
Rosa Maria Rocha
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Tape Casting ◽  
Casting Process ◽  
Aqueous System ◽  
Solid Concentration ◽  
Green Density ◽  
Commercial Alumina ◽  
Acrylic Latex ◽  
Final Density

Tape casting process was used to produce Al2O3 substrates in an aqueous system with acrylic latex emulsion as binder. The present work studied the slurry formulations in aqueous medium of Al2O3 powders with different particle size distribution and made correlation to the green and sintered tapes. Two commercial alumina powders, one sub-micrometric and other micrometric were used. Compositions of Al2O3 slurries with 80 and 83 wt% of solids were prepared by dispersing the powders in water with a dispersant with subsequently additions of 7 and 10 wt% of binder. Sub-micrometric Al2O3 resulted in a high densification tapes regardless solid concentration and binder amount in the slurry, though green density was affected. For micrometric alumina, increasing the solid concentration resulted in a little higher final density.

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