scholarly journals The effect of microsilica and refractory cement content on the properties of andalusite based Low Cement Castables used in aluminum casthouse

Cerâmica ◽  
2010 ◽  
Vol 56 (340) ◽  
pp. 411-421 ◽  
Author(s):  
E. A. Firoozjaei ◽  
A. Saidi ◽  
A. Monshi ◽  
P. Koshy

The bonding system in low cement castables is achieved by the use of calcium aluminate cement, microsilica and reactive alumina. The lime/silica ratio critically impacts the liquid phase formation at high temperatures and subsequently the corrosion resistance and the mechanical and physical properties of the refractory. In the current study, the effects of microsilica and cement contents on the corrosion resistance and the physical and mechanical properties of Andalusite Low Cement Castables (LCCs) refractories were investigated. Alcoa Cup test was used to evaluate the corrosion resistance of the castables at 850 ºC and 1160 ºC. The study showed that an increase in the microsilica/cement ratio improves the physical and mechanical properties of the castable, but at the expense of the corrosion resistance. When a fixed amount of BaSO4 was added to the base refractory material, barium celsian along with glassy phase formation was observed to increase with the increase in the microsilica/cement ratio in the refractory. The presence of the glassy phases was noted to lower the positive effect of Ba-celsian formation on improving the corrosion resistance of the refractory. The observed results were validated using thermodynamic calculations which indicated that Ba-celsian phase was more resistant than Ca-anorthite for applications involving contact with molten aluminum.

2018 ◽  
Vol 33 ◽  
pp. 02056
Author(s):  
Maria Kaddo

The article describes preferable ways of usage of alternative binders for high-rise construction based on aluminate cements. Possible areas of rational use of aluminate cements with the purpose of increasing the service life of materials and the adequacy of the durability of materials with the required durability of the building are analyzed. The results of the structure, shrinkage and physical and mechanical properties of concrete obtained from dry mixes on the base of aluminate cements for self-leveling floors are presented. To study the shrinkage mechanism of curing binders and to evaluate the role of evaporation of water in the development of shrinkage was undertaken experiment with simple unfilled systems: gypsum binder, portland cement and «corrosion resistant high alumina cement + gypsum». Principle possibility of binder with compensated shrinkage based on aluminate cement, gypsum and modern superplasticizers was defined, as well as cracking resistance and corrosion resistance provide durability of the composition.


Alloy Digest ◽  
1983 ◽  
Vol 32 (3) ◽  

Abstract BRUSH Alloy 3 offers the highest electrical and thermal conductivity of any beryllium-copper alloy. It possesses an excellent combination of moderate strength, good corrosion resistance and good resistance to moderately elevated temperatures. Because of its unique physical and mechanical properties, Brush Alloy 3 finds widespread use in welding applications (RWMA Class 3), current-carrying springs, switch and instrument parts and similar components. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-454. Producer or source: Brush Wellman Inc..


Alloy Digest ◽  
1999 ◽  
Vol 48 (10) ◽  

Abstract Kaiser Aluminum alloy KA62 (Tennalum alloy KA62) is a lead-free alternative to 6262. It offers good machinability and corrosion resistance and displays good acceptance of coatings (anodize response). It can be used in place of 6262 because its physical and mechanical properties are equivalent to those of 6262 (see Alloy Digest Al-361, September 1999). This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and surface treatment. Filing Code: AL-362. Producer or source: Tennalum, A Division of Kaiser Aluminum.


FLORESTA ◽  
2005 ◽  
Vol 35 (1) ◽  
Author(s):  
Teresa María Suirezs

Este trabajo tuvo por objetivo, estudiar el comportamiento de las propiedades físicas y mecánicas de la madera de Pinus taeda L. impregnada por vacío-presión con preservador CCA (CrO3; CuO; As2O5) con tres retenciones, 5, 10 y 15 kg/m3. El proceso de impregnado se realizó, por el método Burnett, aplicándose presión y vacío de 7 kg/m2 y – 0,5 kg/m2 respectivamente. Los ensayos de las propiedades físicas y mecánicas se determinaron según lo establecen, las Normas técnicas IRAM (Instituto Argentino de Racionalización de Materiales), ASTM (American Society for Testing and Materials) y DIN (Deutsche Industrie Norm). Las propiedades físicas como ser los pesos específicos aparentes no son afectadas por las retenciones de CCA en la madera. Las contracciones tanto en el sentido tangencial como radial en las maderas impregnadas son menores. Las propiedades mecánicas de resistencia a la flexión estática, compresión paralela a las fibras, tracción perpendicular a las fibras, disminuyen levemente sus valores promedios con respecto a la madera sin impregnar, pero estas diferencias no son estadísticamente significativas, para 95 % de confianza. La impregnación ha producido un efecto positivo en la dureza Janka transversal y en el corte paralelo a las fibras tangencial siendo estas diferencias estadísticamente significativas. Behaviour of the wood of Pinus taeda impregnated with Chrome, Copper, Arsenic (CCA) Abstract The physical and mechanical properties of the wood of Pinus taeda L. without impregnating and impregnating by empty - pressure with preserving CCA (Chrome, Copper, Arsenic) with three retentions, 5, 10 and 15 kg/m3 have been determined and analysed. The impregnation was accomplished in an autoclave applying the Burnett method. The physical and mechanical properties were determined according to the following technical Procedures; IRAM (Argentine Institute for Rationalization of materials), ASTM (American Society for Testing and Material) and DIN (Deutsche Industrie Norm). The results indicate that the specific weights of samples containing different percentages of humidity was not affected by the retentions of CCA in the wood. The shrinkage both in the tangential and radial directions in the impregnated samples were smaller in the impregnated sample. The mechanical resistance to statics flexion, compression parallel to the fibers, traction perpendicular to the fibers, hardness tangential and radial Janka and paralell radial cut, do not show statistically meaningful differences between impregnated and not impregnated samples; however the treatment has produced a positive effect in the hardness transverse Janka and in the parallel cut to the tangential fibers.


2020 ◽  
Vol 1011 ◽  
pp. 151-157
Author(s):  
Sergey Khutorskoy ◽  
Denis Emelyanov ◽  
Alexander Matvievsky ◽  
Vasiliy Smirnov

The study results of the calcareous composites made with the use of activated mixing water are presented. Quicklime and slaked lime are used as lime binders. The mixing water was activated by the electric current and magnetic field in various modes. The effect of water activation on the physical and mechanical properties of slaked and quicklime composites and the resistance to the effects of the biological environment are studied. The water for mixing electromagnetic treatment effectiveness analysis is presented. The increase in the density of materials based on lime, trapped in activated water using ultrasound tests is proven. It was found that the mixing water activation affects the structure formation of composites and, under certain activation conditions, leads to an increase in such physical and mechanical parameters as strength and hardness. The positive effect of the mixing water activation on the lime-based materials’ resistance to microbial growth has been established, and the decrease in the growth of composites based on quicklime and slaked lime has been proved.


2020 ◽  
Vol 322 ◽  
pp. 01001
Author(s):  
Dana Konakova ◽  
Eva Vejmelkova ◽  
Lenka Scheinherrova ◽  
Martin Keppert ◽  
An Cheng ◽  
...  

Basic physical and mechanical properties of several cement composites are determined as functions of thermal load and the results are compared with reference materials. Bulk density, matrix density, and open porosity are measured using the water vacuum saturation method. Compressive and bending strengths are determined according to the European standard. High-temperature coefficient of thermal expansion is obtained using a comparative measurement. Experimental results show that composites based on Portland cement do not resist high temperatures well. Their applicability is limited to 400 °C, due to the damage caused by hydrates decomposition. On the other hand, composites based on calcium aluminate cement exhibit a better thermal stability and retain residual strength even after being exposed to 1000 °C.


Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Zhenkun Hou ◽  
Mengxiong Tang ◽  
Shihua Liang ◽  
Yi Zhu

The physical and mechanical properties of grouting materials greatly affect the friction resistance and the bearing performance of a non-soil-squeezing PHC pipe pile. Orthogonal tests for four factors at five levels were carried out to optimize the proportion of the water–cement mixture by using Portland cement as a raw material and a water-reducing agent, expansion agent and early-strength agent as additives. The following conclusions were obtained: (1) Both the water–cement ratio and the dosage of water-reducing agent are positively correlated with the fluidity of the water–cement mixture and have the greatest influence on the fluidity, followed by the expansion agent and early-strength agent. The saturation point of the water-reducing agent is 1.5%. (2) The strength of the grouting body decreases linearly with the increase of the water–cement ratio, and the dosage of the water-reducing agent has no obvious effect on the strength. As the dosage of expansion agent increases, the strength of the grouting body decreases rapidly. The expansion agent mainly plays a key role in the middle and late stages of the hardening process of the slurry. Early-strength agents have a greater impact on the early strength, but less on the later strength. When the slurry is solidified for 3 h, the early-strength agent has the greatest impact on the strength with an optimal dosage of 5%. (3) The volume of the grouting body has an inverse relationship with the water–cement ratio, and the optimal amount of expansion agent is 12%. The incorporation of an expansion agent makes the volume increase of the grouting body exceed the volume shrinkage ratio caused by the hardening of the grouting body with a curing time of more than 3 days, ensuring a slight increase in the volume of the grouting body. After 3 days, even though the effect of the expansion agent is gradually weakened, it can still ensure that the volume of the grouting body does not shrink. With the increase of the amount of water-reducing agent, the volume of the grouting body gradually decreases. When the amount of water-reducing agent exceeds 1.5%, the volume of the grouting body no longer decreases. (4) The early-strength agent has almost no effect on the volume of the grouting body. When the curing time is 3 h, the water–cement ratio has the greatest influence on the volume of the grouting body, followed by the water-reducing agent, and, finally, the expansion agent. After 3 h, the water–cement ratio still has the greatest influence, and the influence of the expansion agent gradually exceeds that of the water-reducing agent. The water-reducing agent mainly affects the volume of the grouting body in the water separation stage, and the expansion agent mainly plays a role in the middle and late stages of the slurry solidification. After optimized ratio analysis, the fluidity of the water–cement mixture can be improved, the volume shrinkage ratio rate can be lowered and the early strength can be increased.


Alloy Digest ◽  
1981 ◽  
Vol 30 (10) ◽  

Abstract MUELLER Alloy 2300 is an alpha brass containing 15% zinc. It has good physical and mechanical properties, excellent cold-working characteristics and a pleasing red color. Its low zinc content makes it resistant to dezincification and it is more resistant to stress-corrosion cracking than brasses with higher zinc contents. Typical uses are plumbing pipe and condenser and heat-exchanger tubes. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-424. Producer or source: Mueller Brass Company.


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