scholarly journals Oxidation and Corrosion Behavior of New Low-Cost Ti-7Fe-3Al and Ti-7Fe-5Cr Alloys from Titanium Hydride Powders

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 254 ◽  
Author(s):  
Eduardo Reverte ◽  
Sophia A. Tsipas ◽  
Elena Gordo

High production costs of Ti alloys usually hinders their use in industry sectors like the automotive and hence, low-cost titanium alloys could broaden titanium alloy usage. This work presents the study of three alloys— Ti-Fe, Ti-Fe-Al, and Ti-Fe-Cr—produced by powder metallurgy methods. The design of the compositions was aimed at reducing cost and enhance the oxidation and corrosion resistance while not decreasing the mechanical performance. The use of titanium hydride as raw material instead of Ti powder is highlighted as a key feature in the design and manufacturing procedure of the alloys. Introducing a dehydrogenation process during sintering favors the densification process while reducing the oxygen contamination and the production cost. There is a lack of studies focused on the implementation of affordable PM Ti alloys in high demanding environments. Therefore, a study of high temperature oxidation resistance and electrochemical behavior was performed.

2017 ◽  
Vol 9 (10) ◽  
pp. 47
Author(s):  
Nitalo André Farias Machado ◽  
Hosana Aguiar Freitas De Andrade ◽  
Luisa Julieth Parra-Serrano ◽  
Marileia Barros Furtado ◽  
Raissa Rachel Salustriano da Silva-Matos ◽  
...  

The wood-based panel industry is growing all over the world, and in many countries the raw material is becoming increasingly inadequate and increasingly expensive. Therefore, new inputs are needed to reduce production costs. The residue of babassu palm fruit after nut extraction process is an alternative, due to its fibrous characteristics, the high availability in the large agroindustrial complexes in the North of Brazil and the low cost. Thus the research was: (i) to determine the mechanical characteristics (tensile strength and elasticity), physicochemical characteristics (density, pH, extractives content and chemical composition) and micro-structural of the babassu residue, comparing it with the particles of Pinus sp., used in commercial panels; (ii) to evaluate the quality of panels manufactured with babassu residue by physical conditions (swelling in thickness and water absorption) and mechanical characterization (elasticity and rupture) based on Brazilian Technical Standards (NBR 14810-2: 2013), American (ANSI A208.1: 2009) and European (EN 312: 2003). Statistical analysis of the data was performed with the aid of Infostat software through analysis of variance using Tukey test at the 5% probability level. The babassu residue has technological characteristics that allow its use in particleboard production. However, there are particularities that may compromise its use, such as high silica content and high density.  Particleboard made from babassu residue presented mechanical performance above that required by current normative documents. However, for the physical properties, especially for the porosity of the particleboard of babassu, the obtained values were lower than the required minimum.


2016 ◽  
Vol 7 (2) ◽  
pp. 42
Author(s):  
Aparecida De Fátima Oliveira Silva ◽  
Leila Maria Girondi ◽  
Suellen Jensen Klososki ◽  
Tatiana Colombo Pimentel ◽  
Carlos Eduardo Barão

Cassava bagasse, regarded as an agricultural residue can be used as raw material in the development of new products. Cereal bars are foods that have increasingly gained consumers because of the practical use. The objective of this study was to evaluate the effect of adding cassava bagasse (0, 8 and 25%) on the chemical composition and sensory acceptance of coconut cereal bars with Brazil nuts. Cereal bars with cassava bagasse had higher moisture, protein and carbohydrates (fiber) contents than cereal bars without bagasse, lower ash contents and similar fat content. The addition of cassava bagasse caused a decrease in the acceptance of the cereal bars only in the concentration of 25%, however, the products had hedonic values greater than 7 in a 9-point hedonic scale and acceptability indices higher than 80%, indicating that consumers moderately liked them. It can be concluded that the use of up to 25% cassava bagasse in the cereal bar formulation yields products with improved nutritional value and appropriated consumer acceptance. The addition of cassava bagasse to food products is a good alternative in the use of this byproduct, due to the sensory characteristics of the obtained products and the reduction of production costs, because the cassava bagasse has low cost and increases the production yield.


2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Fayong Yang ◽  
Haibin Li ◽  
Guijuan Zhao ◽  
Ping Guo ◽  
Wenbo Li

Enlarging local raw material utilization and reducing project costs is a new trend in the construction field. Under this background, sandstone was utilized in a cement-stabilized base in this study. The mineral composition of sandstone and the proportion of each mineral composition in the parent rock were analyzed using X-ray diffraction. To verify its feasibility, sandstone, syenite, marble, and basalt aggregates were selected to test the mechanical properties and road performance of the four aggregate concretes at 7, 28, 90, and 180 days. The test results showed that although the sandstone slump was the lowest at 60, the workability met the requirement. Compressive strength, tensile elasticity modulus, and axial tensile strength of concrete increased with age in all the concrete specimens, and the strength at each inspection time of sandstone was equivalent to that of marble, lower than that of basalt but higher than that of syenite. The early compressive strength of sandstone concrete is slightly lower than the compressive strength of marble concrete, and the 7 d and 28 d strengths were lower than 14% and 11%, respectively, but their 90 d and 180 d compressive strengths were the same. The crack resistance and frost resistance of sandstone were slightly inferior to those of syenite but better than those of basalt and marble. After 300 freeze-thaw cycles of the four aggregate concretes, the mass-loss rate of the test specimens was less than 5%, indicating that the frost resistance can meet the requirements. The various technical indexes of sandstone mixture could meet the current industry standards, and crack resistance, frost resistance, and fatigue resistance were good, which verified the feasibility of using sandstone for cement-stabilized base and provided a low-cost alternative for road construction.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6784
Author(s):  
Jinming Liu ◽  
Boyu Ju ◽  
Wei Xie ◽  
Ting Zhou ◽  
Haiying Xiao ◽  
...  

Coral concrete has low cost and convenient materials, making it an excellent raw material for processing. However, its lower strength limits the application of coral concrete. Surface modification is expected to increase the properties of porous coral concrete. In this study, single and compound modification treatments were applied to the surface of a coral aggregate to improve its properties for promoting the mechanical performance of coral concrete. The results showed that the micro-aggregate effect and pozzolanic activity of granulated blast furnace slag (GBFS) and the permeability and polycondensation of sodium silicate (SS) could be mutually promoted. The GBFS and SS could effectively fill the pores of the coral aggregate, enhancing the properties of the aggregate, such as density and load-bearing capacity, and reducing the water absorption and crushing index by more than 50%. GBFS and SS could intensify and accelerate the hydration of cement, and generate a large number of hard hydration products at the interfacial transition zone (ITZ), which could strengthen the bonding between the aggregate and mortar, improving the strength of the ITZ. The compressive strength of the coral concrete was significantly increased.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5635
Author(s):  
Jerzy Korol ◽  
Marcin Głodniok ◽  
Aleksander Hejna ◽  
Tomasz Pawlik ◽  
Błażej Chmielnicki ◽  
...  

Sewage sludge is a high-volume and low-cost waste commonly generated worldwide, so its utilization is a vital issue. The application of this waste in the manufacturing of lightweight aggregates was investigated. The process was performed using intensive mixers with volumes of 5 and 30 L, as well as the industrial 500 L mixer. Then, granulates were sintered in a tube furnace. The influence of composition and mixer size on the particle size, microstructure, mechanical performance, and stability of lightweight aggregates in different environments was analyzed. The best results were obtained for a 500 L mixer, enhancing the industrial potential of the presented process. Increasing the share of sewage sludge in the composition of aggregates enhanced their porosity and reduced the specific weight, which caused a drop in compressive strength. Nevertheless, for all analyzed materials, the mechanical performance was superior compared to many commercial products. Therefore, sewage sludge can be efficiently applied as a raw material for the manufacturing of lightweight aggregates. The presented results confirm that a proper adjustment of composition allows easy the tailoring of aggregates’ performance and cost.


Clay Minerals ◽  
2020 ◽  
Vol 55 (2) ◽  
pp. 101-111
Author(s):  
Chedlia Ounissi ◽  
Salah Mahmoudi ◽  
Luca Valentini ◽  
Ali Bennour ◽  
Enrico Garbin ◽  
...  

AbstractThe aim of this study was to help drive the Tunisian construction industry towards a more sustainable approach given the existence of abundant local raw material deposits that could be exploited for the production of low-CO2 binders. Various clay sediments from the Kebili region (southern Tunisia) were characterized by chemical analysis, X-ray diffraction, thermal analysis and geotechnical tests to determine their suitability for the preparation of geopolymer binders. The clays consist of illite and kaolinite with other accessory minerals. To test the possibility of using these materials as precursors for the production of low-CO2 and low-cost geopolymers, the raw samples were calcined and activated by addition of solid sodium silicate. Compressive strength tests performed on four alkali-activated clays show that promising mechanical performance may be achieved, with mechanical strength values as high as 25 MPa after 7 days, depending on the clay composition. The mechanical strength is related to the SiO2:Al2O3 and Al2O3:(NaO2 + K2O) ratios. Careful selection of the raw materials is, therefore, an essential step in the exploitation of clay deposits to be used for the production of ecological materials such as geopolymers.


2009 ◽  
Vol 160 (7) ◽  
pp. 195-200
Author(s):  
Reto Hefti

In the mountainous canton Grisons, much visited by tourists, the forest has always had an important role to play. New challenges are now presenting themselves. The article goes more closely into two themes on the Grisons forestry agenda dominating in the next few years: the increased use of timber and climate change. With the increased demand for logs and the new sawmill in Domat/Ems new opportunities are offered to the canton for more intensive use of the raw material, wood. This depends on a reduction in production costs and a positive attitude of the population towards the greater use of wood. A series of measures from the Grisons Forestry Department should be of help here. The risk of damage to infrastructure is particularly high in a mountainous canton. The cantonal government of the Grisons has commissioned the Forestry Department to define the situation concerning the possible consequences of global warming on natural hazards and to propose measures which may be taken. The setting up of extensive measurement and information systems, the elaboration of intervention maps, the estimation of the danger potential in exposed areas outside the building zone and the maintenance of existing protective constructions through the creation of a protective constructions register, all form part of the government programme for 2009 to 2012. In the Grisons, forest owners and visitors will have to become accustomed to the fact that their forests must again produce more wood and that, on account of global warming, protective forests will become even more important than they already are today.


Author(s):  
SAFITRI NURHIDAYATI ◽  
RIZKI AMELYA SYAM

This study aims to analyze whether the difference that occurs in the cost of raw materials, direct labor, and factory overhead costs between the standard costs and the actual costs in PLTU LATI is a difference that is favorable or unfavorable. Data collection techniques with field research and library research. The analytical tool used is the analysis of the difference in raw material costs, the difference in direct labor costs and the difference in factory overhead costs. The hypothesis in this study is that the difference allegedly occurs in the cost of raw materials, direct labor costs, and factory overhead costs at PT Indo Pusaka Berau Tanjung Redeb is a favorable difference. The results showed that the difference in the cost of producing MWh electricity at PT Indo Pusaka Berau Tanjung Redeb in 2018, namely the difference in the price of raw material costs Rp. 548,029.80, - is favorable, the difference in quantity of raw materials is Rp. 957,216,602, - is (favorable) , the difference in direct labor costs Rp 2,602,642,084, - is (unfavorable), and the difference in factory overhead costs Rp 8,807,051,422, - is (favorable) This shows that the difference in the overall production cost budget is favorable or profitable. This beneficial difference shows that the company is really able to reduce production costs optimally in 2018.  


2020 ◽  
pp. 712-721
Author(s):  
Jan Maarten de Bruijn de Bruijn

The bought sugar in the processed raw material (either beet or cane) comprises a high financial value and may contribute to somewhere around 50% of the white sugar production costs. It is therefore of the utmost importance to minimize sugar losses along the process and produce as much white sugar as possible from the raw material. This paper explains the principle of technical accounting as tool to control sugar extraction and losses in beet sugar manufacture. The sugar mass balance used to calculate the overall sugar extraction yield, as well as several simple calculations proposed for estimating the different sugar losses (like e.g. extraction (diffusion) losses, infection losses, sugar losses in molasses, etc.) in the subsequent process steps will be explained in detail. Proper technical accounting is considered indispensable for continuous process control and process improvement in pursuit of best-practice operation and cost-leadership.


Cellulose ◽  
2021 ◽  
Author(s):  
Aayush Kumar Jaiswal ◽  
Vinay Kumar ◽  
Alexey Khakalo ◽  
Panu Lahtinen ◽  
Katariina Solin ◽  
...  

AbstractHigh-consistency processing of fibrillated cellulose materials is attractive for commercial applications due to potential for lowered production costs, energy savings and easier logistics. The current work investigated structure–property relationships of fibrillated cellulose suspensions produced at 20% consistency using VTT HefCel (High-consistency enzymatic fibrillation of cellulose) technology. Morphological examination of the fibrillated materials revealed that enzymatic action on the cellulose substrates was not a direct function of enzyme dosage but rather was dependent on the raw material composition. Furthermore, shear viscosity of the HefCel suspensions was found to decrease with increasing enzyme dosage while the water retention increased. The shear viscosity followed power law relationship with the power law index varying in the range 0.11–0.73. The shear-thinning behavior decreased with increasing consistency. Moreover, suspension viscosity ($$\upmu$$ μ ) was found to be highly dependent on the consistency ($$\mathrm{c})$$ c ) as $$\upmu \sim {\mathrm{c}}^{\mathrm{m}}$$ μ ∼ c m , with $$\mathrm{m}$$ m ranging from 2.75 to 4.31 for different samples. Yield stress (τy) of the HefCel suspensions was measured at 7 and 10% consistencies. The performance of the fibrillated cellulose grades in a typical application was demonstrated by casting films, which were characterized for their mechanical properties. Graphic abstract


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