Effects of the Z Value on the Properties of β-Sialon/ZrO2 Composites

2012 ◽  
Vol 476-478 ◽  
pp. 471-474
Author(s):  
Rui Sheng Wang ◽  
Jun Cong Wei ◽  
Jun Hong Zhao ◽  
Yong Wu He ◽  
Fu Hua Peng
Keyword(s):  
Water Absorption ◽  
Bulk Density ◽  
Absorption Rate ◽  
Apparent Porosity ◽  
Modulus Of Rupture ◽  
X Ray Diffraction ◽  
Water Absorption Rate ◽  
Shock Resistance ◽  
Z Value ◽  
Sialon Powder

β-Sialon/ZrO2 composites were prepared using 10 wt. % β-Sialon powder (where the z =1, 2, 3, respectively) and 90 wt. % ZrO2 powder as the starting materials. The effects of the Z value of β-Sialon on the bulk density, apparent porosity, water absorption rate, room temperature modulus of rupture, thermal shock resistance, microstructure and composition of the composites were investigated. The microstructure of sintered specimens was analyzed by scanning electron microscope (SEM), and X-Ray diffraction (XRD). The results revealed that with increase of the Z value of β–Sialon, bulk density gradually increased, apparent porosity and water absorption rate gradually decreased. The specimen possessed a maximum MOR (71.46MPa) when the z=2. In carbon embedded condition, the residual strength ratio of the specimen reached 60% and the lowest thermal expansion rate was obtained (0.55%) when the z=1. The phase compositions were cubic ZrO2 (c-ZrO2) and monoclinic ZrO2 (m-ZrO2). β-Sialon/ZrO2 composites exhibited overall optimum performance when the z equals 2

Effect of Silica Sol on the Properties of Unfired Mullite Rollers

2010 ◽  
Vol 97-101 ◽  
pp. 526-529
Author(s):  
Kai Huang ◽  
Yuan Bing Li ◽  
Bing Feng ◽  
Qing Shun Wu ◽  
Li Yang ◽  
...  
Keyword(s):  
Water Absorption ◽  
Bulk Density ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Absorption Rate ◽  
Silica Sol ◽  
Shock Resistance ◽  
Α Al2o3 ◽  
Micro Silica ◽  
White Fused Alumina

An unfired mullite roller was produced by using mullite roller waste, white fused alumina, α-Al2O3, clay and micro silica, meanwhile silica sol was used to partially substitute for micro silica as the SiO2 source. The effect of silica sol on the properties of unfired mullite roller was investigated. The results showed that the microstructure and properties of the unfired mullite roller prepared with silica sol were improved. With the increase of silica sol, the COMR, bulk density and thermal shock resistance increased, and the water absorption rate decreased. When silica sol was 8w/t%, treated temperature was 1200°C, the CMOR of unfired mullite roller was more than 50MPa.

Fabrication and Properties of Al2O3-SiC/Sialon Composite Refractories

2012 ◽  
Vol 512-515 ◽  
pp. 908-911
Author(s):  
Ding Yun Ye ◽  
Yan Gai Liu ◽  
Zhao Hui Huang ◽  
Ming Hao Fang ◽  
Yang Yang Liu
Keyword(s):  
Water Absorption ◽  
Bulk Density ◽  
Carbothermal Reduction ◽  
Room Temperature ◽  
Bending Strength ◽  
Raw Materials ◽  
Apparent Porosity ◽  
Low Grade ◽  
Sialon Powder ◽  
Aluminate Cement

Sialon powder was synthesized using low grade bauxite as raw materials by carbothermal reduction-nitridation reaction. The influence of synthesizing temperatures (1300°C, 1350°C, 1400°C, 1450°C, 1500°C and 1550°C) on the phases of the final products was studied by XRD technique. β-Sialon (Z=3) formed at 1350°C and decreased when the temperature was higher than 1450°C. The optimizing reaction temperature for preparing Sialon was 1450°C. The Al2O3-SiC/Sialon composite refractories were prepared at 200°C, 400°C and 600°C for 24h with white corundum, brown corundum, SiC, Sialon powders prepared at 1450°C and calcium aluminate cement. The bulk density, apparent porosity, water absorption and bending strength of the Al2O3-SiC/Sialon composite refractories at room temperature were studied. The results show that the bulk density decreased and then increased with the enhancing of the temperature and reached the highest value of 2.43g/cm3 at 200°C. The apparent porosity and water absorption reached the lowest values of 26.68% and 10.99% at 200°C respectively. The bending strength decreased as the temperature increased, reached the highest value of 0.73MPa at 200°C.

scholarly journals Preliminary Study of Oil Palm Decanter Cake Natural Polymer Composite (OPDC-NPC)

2014 ◽  
Vol 911 ◽  
pp. 40-44 ◽  
Author(s):  
Muhammad Aqif Adam ◽  
Alawi Sulaiman ◽  
Che Mohd Som Said ◽  
Ayub M. Som ◽  
Azhari Samsu Bahruddin ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Polymer Composite ◽  
Palm Oil ◽  
Oil Palm ◽  
Absorption Rate ◽  
Natural Fiber ◽  
Natural Polymer ◽  
Water Absorption Rate ◽  
Decanter Cake

Palm oil industry produces huge amount of oil palm decanter cake (OPDC). Currently it is not yet commercialized however due to its characteristics, it can be used to produce oil palm decanter cake natural polymer composite (OPDC-NPC). NPC is a type of material made by combining natural fiber with polymer. Therefore the objective of this paper is to produce NPC from OPDC and then determine its mechanical and physical properties such as elasticity, stiffness, tensile strength and water absorption rate. The OPDC samples were collected from Felda Trolak Palm Oil Mill. Prior to NPC development, the oil was removed from OPDC using hexane soxhlet extraction method. OPDC-NPC was fabricated using molding method where the mixture of 95% polypropylene (PP) and 5% OPDC were mixed using twin-screw extruder. The results showed that OPDC-NPC has an elasticity of 2231 MPa, stiffness of 30 MPa, tensile strength of 32 MPa and water absorption rate of 0.16 % which was slightly better with the other types of fibers.

scholarly journals Analysis on the barrier properties of thin film PLA/PBAT reinforced with microcrystalline cellulose

2021 ◽  
Vol 2129 (1) ◽  
pp. 012059
Author(s):  
Sitti Fatimah Mhd Ramle ◽  
Aqilah Abdul Rahim ◽  
Nur Hafizzah Jusoh ◽  
Nurul Fazita Mohammad Rawi ◽  
Che Ku Abdullah Che Ku Alam
Keyword(s):  
Thin Film ◽  
Water Absorption ◽  
Microcrystalline Cellulose ◽  
Absorption Rate ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Plastic Pollution ◽  
Water Absorption Rate ◽  
Environmental Friendly ◽  
Hydrolysis Process

Abstract In recent times, awareness on plastic pollution had increase which brings innovation on new productions to be environmental friendly. Various polymers has been used to analyse the suitability to produce thin films. In this study, Poly lactic acid (PLA) and Polybutylene adipate terephthalate (PBAT) reinforced with microcrystalline cellulose (MCC) were investigated. MCC were produced from selected bamboo for obtaining cellulose, then followed by an acidic hydrolysis process for the processing of microcrystalline cellulose (MCC). In this study, the thin film are focusing on the barrier properties such as water absorption, solvent resistance and absorption test. From the results shows that, the lowest rate of water absorption rate is 1.9% by 1% B-MCC/PLA/PBAT, meanwhile, the highest rate of water absorption is 60.1% by 5% C-MCC/PLA/PBAT. The water absorption rate decrease gradually with the decreasing of amount of MCC in the samples. Lastly, the thin film samples can resist with oleic acid solvents as the condition of thin film samples is still remain but they were not resistance with xylene as the thin film samples were shrinked and degraded. This thin film have a potential to replace the non-biodegradable petrochemical polymer based on their properties such as food contact, availability and cost.

scholarly journals WATER ABSORPTION AND DRYING SHRINKAGE OF RECYCLED FOAMED AGGREGATE CONCRETE

2018 ◽  
Vol 30 (3) ◽  
Author(s):  
Chai Teck Jung ◽  
Tang Hing Kwong ◽  
Koh Heng Boon
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Drying Shrinkage ◽  
Casting Process ◽  
Concrete Specimen ◽  
Sieve Analysis ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Water Absorption Rate ◽  
Foamed Concrete

Abstract: This paper presents some experimental results and discusses the used of recycled foamed aggregates as natural coarse aggregates replacement in producing concrete. The physical properties of recycled foamed aggregates concrete were investigated. The properties studied are water absorption and drying shrinkage from the concrete early ages until the periods of 56 days. The 100 mm x 100 mm cube specimen was used to study the water absorption at the age of 7, 28 and 56 days. Meanwhile, the 100 mm x 100 mm x 300 mm length prism had been casted and used for drying shrinkage test for recycled foamed aggregates concrete. The foamed aggregates was produced from crushing recycled foamed concrete blocks. It were coated with cement paste to reduce its water absorption ability during casting process. Superplasticizer was used to maintain the workability of fresh concrete with a slump vary between 50 mm to 100 mm. The physical tests were conducted on recycled foamed aggregates to determine their initial properties such as loose bulk density, sieve analysis and water absorption rate. Recycled foamed aggregate concretes were produced with varied water cement ratio. The results obtained indicated that the linear elastic relationship between water cement ratio and water absorption rate. The higher the water cement ratio of concrete specimen will obtained higher water absorption rate. Vice versa, the density is low for drying shrinkage. The water absorption decreased while drying shrinkage becomes more stabilized over curing period.

Mechanical Properties and Thermal Conductivity of Lightweight Clay Bricks Fabricated with a Powdered Marble Dust Additive

2018 ◽  
Vol 777 ◽  
pp. 465-470
Author(s):  
Sutas Janbuala ◽  
Mana Eambua ◽  
Arpapan Satayavibul ◽  
Watcharakhon Nethan
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Bulk Density ◽  
Firing Temperature ◽  
Apparent Porosity ◽  
Clay Brick ◽  
Clay Bricks ◽  
Marble Dust

The objective of this study was to recycle powdered marble dust to improve mechanical properties and thermal conductivity of lightweight clay bricks. Varying amounts of powdered marble dust (10, 20, 30, and 40 vol.%) were added to a lightweight clay brick at the firing temperatures of 900, 1000, and 1100 °C. When higher quantities of powdered marble dust were added, the values of porosity and water absorption increased while those of thermal conductivity and bulk density decreased. The decrease in apparent porosity and water absorption were also affected by the increase in firing temperature. The most desirable properties of the clay bricks were obtained for the powdered marble dust content of 40 vol.% and firing temperature 900 °C: bulk density of 1.20 g/cm3, compressive strength 9.2 MPa, thermal conductivity 0.32 W/m.K, and water absorption 22.5%.

The Influences of Addition of MgCO3 on the Properties of the Magnesia Prepared Using Magnesite

2018 ◽  
Vol 281 ◽  
pp. 230-235
Author(s):  
Wang Nian Zhang ◽  
Li Wang ◽  
Ni Deng
Keyword(s):  
Grain Size ◽  
Bulk Density ◽  
Raw Materials ◽  
Apparent Porosity ◽  
X Ray Diffraction ◽  
Linear Change ◽  
Change Rate ◽  
X Ray ◽  
Before And After ◽  
Calcination Method

Micropowder MgCO3 was added into magnesite as raw materials to prepare magnesia using a two-step calcination method. The sample magnesite was characterized use X-ray diffraction (XRD) and scanning electron microscopy (SEM). Experimental results showed that the sample insulated at 1600° C for 3 hours before and after sintering presented a linear change rate of 15.6 % in the case of without adding micropowder MgCO3, the prepared magnesia had a bulk density of 2.31 g/cm3 and apparent porosity of 32.8 %, while MgO grain size was 3.11 μm. In the case of adding 8 % micropowder MgCO3, the sample magnesite before and after sintering showed a linear change rate of 17.9 %. The bulk density, apparent porosity of prepared magnesia were 2.46 g/cm3 and 28.1 % respectively, while the grain size of MgO was 5.15 mm.

scholarly journals Durability Studies on the Recycled Aggregate Concrete in China over the Past Decade: A Review

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Zhiming Ma ◽  
Qin Tang ◽  
Dingyi Yang ◽  
Guangzhong Ba
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Rapid Urbanization ◽  
Aggregate Concrete ◽  
The Past ◽  
Water Absorption Rate ◽  
Average Water

Since China hosted the Olympic Games in 2008, a mass of construction and demolition (C&D) wastes were produced with the rapid urbanization construction. Recycling the C&D waste into recycled aggregates (RA) is an effective method for reducing the amount of C&D wastes. Many studies on the properties of RA and the durability of recycled aggregate concrete (RAC) were conducted in China over the past decade. Due to the restrictions of various languages, some valuable studies on the durability of RAC are hard to be acquired by the scholars around the world. Therefore, this paper is developed to review the studies on the durability of RAC in China, and the shrinkage behavior, chloride permeability, carbonation behavior, and freeze-thaw resistance of RAC are, respectively, introduced. Considering the waste concrete, bricks, and ceramics used in preparing RA are frequently mixed together in China, this study proposes an index of average water absorption rate to quantify the effects of RA types, quality, and replacement percentages on the durability of RAC. Meanwhile, the relationship between the average water absorption rate of RA and the durability parameters of RAC is established. Finally, the improving methods of RAC durability are introduced, and the RA particle shaping and carbonation modification are emphasized.

Properties of Dan Kwian, Sukhothai and Ratchaburi Pottery Clays Fired at 700 and 900 °C

2014 ◽  
Vol 608 ◽  
pp. 47-61
Author(s):  
Nonglak Meethong ◽  
Wanwisa Pattanasiriwisawa ◽  
Weenawan Somphon ◽  
Waraporn Tanthanuch ◽  
Sutham Srilomsak
Keyword(s):  
Specific Gravity ◽  
Comparative Study ◽  
Water Absorption ◽  
Bulk Density ◽  
Firing Temperature ◽  
Reflectance Spectra ◽  
Modulus Of Rupture ◽  
Regression Equations ◽  
Statistical Software

Dan Kwian, Sukhothai and Ratchaburi pottery clays are economically important pottery clays. They are well known in the Thai ceramic society for making Dan Kwian pottery, Sawankhalok pottery and Dragon jars, respectively. There have been several studies of these pottery clays. However, few of them used statistics to analyze their results. This work is a comparative study of the compositions and properties of these three pottery clays using statistical software to analyze the results. Results show that the major components of these pottery clays are SiO2 and Al2O3. The Modulus of Rupture (MOR) of each pottery clay fired at 700°C are not significantly different. Sukhothai pottery clay fired at 900°C has a higher MOR and bulk density while its porosity, water absorption and apparent specific gravity are less than those of the Dan Kwian and Ratchaburi pottery clays fired at the same temperature. Additionally, the current study developed regression equations for estimating the properties of all pottery clays under study. Finally, it was found that the L*, a*, b* and reflectance spectra of all pottery clays increased when firing temperature was increased from 700 to 900°C.

The Influence of Different Hydrophobic Agent on the Water Absorptivity of Foam Concrete

2014 ◽  
Vol 665 ◽  
pp. 192-195 ◽  
Author(s):  
Yu Zheng ◽  
Chang Sheng Pan ◽  
Jian Li ◽  
He Chi Pan ◽  
Jun Yi Hu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Water Absorption ◽  
Thermal Performance ◽  
Absorption Rate ◽  
Foam Concrete ◽  
Organic Silicon ◽  
Water Absorption Rate ◽  
Hydrophobic Agent ◽  
High Absorption ◽  
High Fatty Acids

Foam concrete products had high absorption rate due to a large number of bubbles dispersion in it.which has serious effects upon the overall thermal performance of material and the durability of construction.Three methods were studied which includes Organic Silicon hydrophobic agent、High fatty acids hydrophobic agent and hydrophobic agent F in order to reduce the water absorption rate.Results show that the water absorption rate was reduced significantly with mixed High fatty acids. The water absorption rate drops of 68.2%, and the organic silicon is in a second place , and the hydrophobic agent F is the worst.

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