|Jerzy J. Sobczak, Ludmil B. Drenchev|
This paper discusses some theoretical aspects of the design of ultralight materials. Potential application of syntactic foams in the fabrication of composites lighter than air is also analyzed. Carbon allotropic forms (fullerenes, colossal carbon tubes) and some non-carbon matters are considered as components of ultralight composites. Calculations for the size of fullerenes, the number of carbon atoms in their structure and thickness of reinforcing phase are presented. It is concluded that 3D carbon molecules (fullerenes) and colossal carbon tubes are the most promising components for design of ultralight metallic materials which can be lighter than air.
Keywords: ultralight materials, composites, syntactic foams, carbon allotropic forms,
Download 1.75 MB >>
Piotr Dudek, Aleksander Fajkiel, Tomasz Reguła, Janusz Mielniczuk
The article presents the results of research on the selection of optimum technological parameters of the hot-chamber die casting machine operation to make castings in AM50 magnesium alloy, coated next with the decorative and protective coatings. Castings of this type require special care during performance, because in addition to the high mechanical properties and low porosity, they should have a very good surface finish (proper texture and roughness, and absence of surface defects such as flow lines, folds, streaks, etc). For the specified detail (cast handle), a plan of the experiment was developed, according to which studies were carried out on a die-casting stand operating in the POLMAG Foundry to determine the important parameters affecting the surface quality of castings.
Keywords: hot-chamber die casting machine, protective-decorative coatings, porosity, roughness,
Download 1.37 MB >>
Jerzy Stachańczyk, Zbigniew Maniowski, Stanisław Pysz, Jan Krawczyk
On the example of a street inlet casting, the metal flow in the gating system on entering the mould cavity and inside the mould was depicted. The effect of the technique by which the metal is fed into the mould cavity on the final properties of castings was examined. Special attention has been paid to the correct process of air evacuation from the mould cavity and to the effect of metal mixing with air as a result of the feeding technique, i.e. the design of the ingates. The analysis was performed for the traditional gating system, and also for the system using filters.
Keywords: computer simulation, gating and feeding system, filtration of molten metal,
Download 969.0 KB >>
Smart nanomaterials are those whose structures and components exhibit peculiar and welldeveloped physical, chemical, and biological properties caused by their nanosized dimensions. It is nanotechnology that deals with the problem of obtaining and using smart nanostructures, in which at least one dimension is expressed in a nanometric scale of 0.1-100 nm. Nanotechnology is a modern science that creates a great many possibilities. The primary objective of nanotechnology is the use of unique characteristics by control of the atomic and molecular particles and development of an effective process for their preparation and use.
Keywords: nanomaterial, nanotechnology, nanostructure, biomimetics,
Download 1.27 MB >>