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Number of results: 17
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Abstract

Simplifications used in simulation program codes require the use of substitute parameters in the material databases (also called apparent or substitutive). On the one hand, they formally fit into the records used in the heat flow model, porosity, properties etc. and on the other hand they should be determined in conditions most similar to the real casting-mould system.

The article presents results of a research on thermophysical parameters of gypsum mould used for precision casting moulds. Experiments were carried out on a cylindrical mould made of Plasticast gypsum, in which the heat source was a cylinder filled with liquid aluminium alloy of the temperature of 655°C. Energetic validation was carried out by using the NovaFlow&Solid ver. 6.3 simulation code. As a result of validation tests, substitute thermophysical parameters of gypsum were determined. For determined parameters, best-fit of solidification time from the experiment and simulation was obtained and the curves of gypsum mass heating were satisfactorily recreate.

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Authors and Affiliations

Ł. Bernat
P. Popielarski
ORCID: ORCID
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Abstract

The results of the Charpy impact test of AE-type magnesium alloys produced by the high pressure die casting method are presented. Three alloys with different weight fractions of rare earth elements (RE; e.g. 1, 3 and 5 wt%) and the same mass fraction of aluminium (5 wt%) were prepared. The casts were fabricated using a typical cold chamber high pressure die casting machine with a 3.8 MN locking force. Microstructural analyses were performed by means of a scanning electron microscope (SEM). The impact strength (IS) was determined using a Charpy V hammer with an impact energy equal to 150 J. The microstructure of the experimental alloys consisted of an -Mg solid solution and Al11RE3, Al10Ce2Mn7 and Al2RE intermetallic compounds. The obtained results show the significant influence of the rare earth elements to aluminium ratio on the impact strength of the investigated materials. Lower the RE/Al ratio in the chemical composition of the alloy results in a higher impact strength of the material.

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Authors and Affiliations

Katarzyna Braszczyńska-Malik
ORCID: ORCID
M.A. Malik
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Abstract

Sodium silicate is one of the most successful inorganic binder. Along with the broad application of sodium silicate for domestic and industrial purposes, the composition analysis, include modulus (m), ratio of SiO2:Na2O, Na2O%, SiO2%, and solid-containing content, is important for the products strength and service life. However, it is perplexing to operate, inefficient and low precision for traditional standard testing method of these parameters. In this study, an automatic measurement system of sodium silicate composition analysis, with the potential electrode for potentiometer titration, micro-controller, PCB, heater, stirrer, printer and micro peristaltic pump, was developed according to the determine method principle. The end-points of pH value in the two titrating steps, first was 4.3 and second was 6.0, were set in the micro-controller to control the reaction in the processing of the sodium silicate composition analysis. And all the potential signals of the pH electrode were transited in the special PCB for the micro-controller.
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Bibliography

[1] Rabbii, A. (2001). Sodium silicate glass as an inorganic binder in foundry industry. Iranian Polymer Journal. 10(4), 229-235.
[2] Stachowicz, M., Pałyga, Ł.& Kȩpowicz, D. (2020). Influence of automatic core shooting parameters in hot-box technology on the strength of sodium silicate olivine moulding sands. Archives of Foundry Engineering. 20(1), 67-72.
[3] Huafang, W., Wenbang, G. & Jijun, L. (2014). Improve the humidity resistance of sodium silicate sands by estermicrowave composite hardening. Metalurgija. 53(4), 455-458.
[4] Nowak, D. (2017). The impact of microwave penetration depth on the process of heating the moulding sand with sodium silicate. Archives of Foundry Engineering. 17(4), 115-118.
[5] M. Stachowicz, K. Granat, & D. Nowak. (2011). Application of microwaves for innovative hardening of environment-friendly water-glass moulding sands used in manufacture of cast-steel castings. Archives of Civil and Mechanical Engineering. XI(1), 209-219.
[6] Zhu, CX. (2007). Recent advances in waterglass sand technologies. China Foundry. 4(1), 13-17.
[7] Masuda Yuki, Tsubota Keiji, Ishii Kenichi, Imakoma Hironobu, Ohmura Naoto. (2009) Drying rate and surface temperature in solidification of glass particle layer with inorganic binder by microwave drying. Kagaku Kogaku Ronbunshu. 35(2). 229-231.
[8] Standardization Administration of the P.R.C. (2008). GB/T4209-2008, Sodium silicate for industry use[S]. Beijing, China Standard Press.
[9] Bourikas K., Kordulis C. & Lycourghiotis A. (2005). Differential potentiometric titration: Development of a methodology for determining the point of zero charge of metal (Hydr)oxides by one titration curve. Environmental Science & Technology. 39(11), 4100-4108.
[10] Fan ZT, Liu M, Wang HF, Long W, Hu XT. (2010). Chinese Patent No. 201010558029.3. Beijing, China National Intellectual Property Administration.
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Authors and Affiliations

Huafang Wang
1
ORCID: ORCID
Quanrun Wang
1
Wu Zhang
1
Xiang Gao
1
Jijun Lu
1
ORCID: ORCID

  1. School of Mechanical Engineering and Automation, Wuhan Textile University, Wuhan 430073, China
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Abstract

Flexible and rigid road pavement deteriorates over time and needs high-performance patching repair materials. Cold mix asphalt patching is an easy and inexpensive repair material to repair potholes and other damaged roads. However, the repaired road pavement fails because it doesn’t have adequate compressive and bonding strength to the substrate. Thus, this research uses high-performance geopolymer repair materials to patch against road pavement potholes substrate. Geopolymer repair materials could improve the bonding strength, making them suitable for road repair purposes. For making geopolymer repair materials, the main materials used were high calcium aluminosilicate source materials such as fly ash, sodium hydroxide, sodium silicate, and water. This study tested the compressive and bonding strength of geopolymer repair materials after 1, 7, 14, and 28 days. This study found that the compressive strength of 90 g of alkali activator was the highest, at 37.0 MPa. The bonding strength improved gradually from day 1 to day 14, and then considerably on day 28. The compressive strength and bonding strength both increase in direct proportion to the amount of alkali activator present. Alkali activator is optimal at 90 grams for compressive strength and bonding strength of geopolymer repair materials.
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Authors and Affiliations

W.W.A. Zailani
1
ORCID: ORCID
N.M. Apandi
1
ORCID: ORCID
M.M.A. Abdullah
2
ORCID: ORCID
M.F.M. Tahir
2
ORCID: ORCID
I Nengah Sinarta
3
Komang Ayu Ni Agustini
3
ORCID: ORCID
S. Abdullah
1
ORCID: ORCID

  1. Universiti Teknologi MARA, College of Engineering, School of Civil Engineering, 40450 Shah Alam, Selangor, Malaysia
  2. Universiti Malaysia Perlis, Center of Excellence Geopolymer and Green Technology (CEGeoGTech), 01000 Kangar, Perlis, Malaysia
  3. Warmadewa University, Faculty of Engineering and Planning, Den Pasa r, 80239, Indonesia

Authors and Affiliations

Wioletta Kamińska
Małgorzata Wilk-Grzywna

Authors and Affiliations

Wioletta Kamińska
Małgorzata Wilk-Grzywna
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Abstract

Production processes at KGHM are complex and require from customers products of constantly higher quality at relatively lowest prices. Such situation results in an increase of the importance of optimisation of processes. As products and technologies change rapidly, technologists at the plant in Głogów have less time to achieve optimisation basing on own experiences. Analysing a particular process, we can e.g. detect occurring disturbances, find factors having an influence on quality problems, select optimal settings or compare various production procedures. Analysis of the course of production process is the basis of process optimisation. One optimisation in case of the process of decopperisation of flash slag can be a change of a technological additive to a less energy-consuming one, and its final result can be an improvement of the productivity index, a change of the relation between final effects and born expenditures, as well as optimisation of production costs.

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Authors and Affiliations

A.W. Bydałek
W. Wołczyński
M. Wędrychowicz
M. Holtzer
B. Basiura
P. Palimąka
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Abstract

The current casting production of castings brings increased demands for surface and internal quality of the castings. Important factors, that influence the quality of casted components, are the materials used for the manufacture of moulds and cores. For the preparation and production of moulds and cores, in order to achieve a low level of casting defects, then it used a high quality input materials, including various types of sands, modified binders, additives, etc. However, even the most expensive raw materials are not a guarantee to achieve the quality of production.

It is always necessary to choose the appropriate combination of input material together with an appropriate proposal for the way of the production, the metallurgical treatment of cast alloy, etc. The aim of this paper is to establish the basic principles for the selection of the base core mixtures components – sands to eliminate defects from the tension, specifically veining. Various silica sand, which are commonly used in foundries of Middle Europe region, were selected and tested.

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Authors and Affiliations

J. Beňo
K. Adamusová
V. Merta
T. Bajer

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