Autor: Herman, A. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: The rationalization of automatic units for HPDC technology
Autorzy:: Herman, A.
Tematy:: automatyka w odlewnictwie
robotyka w odlewnictwie
zarządzanie jakością
odlewanie wysokociśnieniowe
cykl pracy
automation in foundry
robotics in foundry
quality management
high pressure die casting (HPDC)
work cycle
rationalization of automatic unit; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/382755.pdf Link otwiera się w nowym oknie
Opis:: The paper deals with problem of optimal used automatic workplace for HPDC technology - mainly from aspects of operations sequence, efficiency of work cycle and planning of using and servicing of HPDC casting machine. Presented are possible ways to analyse automatic units for HPDC. The experimental part was focused on the rationalization of the current work cycle time for die casting of aluminium alloy. The working place was described in detail in the project. The measurements were carried out in detail with the help of charts and graphs mapped cycle of casting workplace. Other parameters and settings have been identified. The proposals for improvements were made after the first measurements and these improvements were subsequently verified. The main actions were mainly software modifications of casting center. It is for the reason that today's sophisticated workplaces have the option of a relatively wide range of modifications without any physical harm to machines themselves. It is possible to change settings or unlock some unsatisfactory parameters.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: The decreasing of die cracking for HDPC technology by changing parameters of heat treatment
Autorzy:: Herman, A.
Zikmund, P.
Tematy:: metalografia
obróbka cieplna
właściwości mechaniczne
odlewanie ciśnieniowe
metallography
heat treatment
mechanical properties
die material
HPDC technology; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/380274.pdf Link otwiera się w nowym oknie
Opis:: In earlier works were described trends in the production of tools for die casting (hot work). Almost the entire set of issues dealt with may seem insignificant when incompletely assembled acceptance of the material and the associated risks of processing a material with an inappropriate structure, leading to a very early defect of the die. Therefore, further work will focus particularly on identifying the causes of thermal cracks and preventing a suitable choice of acceptance criteria conditions and heat treatment.
Dostawca treści:: Biblioteka Nauki

Artykuł

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Skocz do pozycji: 3.

Tytuł:: Wind- and density-driven water circulation in the Southern Baltic Sea - a numerical analysis
Autorzy:: Herman, A.
Jankowski, A.
Tematy:: wind-driven circulation
density currents
hydrodynamic modeling
Stope Channel
Southern Baltic
Princeton Ocean Model; Pokaż więcej
Wydawca:: Politechnika Gdańska
Powiązania:: https://bibliotekanauki.pl/articles/1964085.pdf Link otwiera się w nowym oknie
Opis:: The study focuses on the hydrodynamic processes in the southern Baltic Sea, with special interest in the Stolpe Channel - the only deep water connection between Bornholm Basin to the west and Gdansk and Gotland Basins to the east. The Channel is an area of strong interactions of wind- and density-driven currents that may lead to a complex flow structure. A three-dimensional numerical model was applied to an analysis of processes mentioned above. Three model versions of different spatial resolution (5, 3 and 1Nm) were used to investigate an influence of this parameter on the model results. The simulations were performed for four main wind directions, for a variable in time wind speed. It was shown that water circulation in the southern Baltic is to a high degree dependent on local anemobaric conditions. The results confirm the hypothesis of Krauss and Brugge that the flow in the Channel is opposite to the wind direction. Numerical grid step can have a decisive influence on the modeled circulation patterns, especially when barotropic andbaroclinic flow components counteract. In such situations - when the flow is bidirectional and mesoscale eddies are generated - high resolution of the model is particularly important.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Dependence of Reoxidation Effect on a Type of Gating System in Investment Casting Technology
Autorzy:: Herman, A.
Vratny, O.
Tematy:: investment casting
gating system
oxide film
metallography; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/379520.pdf Link otwiera się w nowym oknie
Opis:: Nowadays, there are growing demands on the accuracy of production. Most of this is reflected in precise manufacturing, such as the investment casting process. Foundries are looking for causes of defects in some cases for a very long time, and it may happen that the source of defects is completely different from what was originally assumed. During the casting process there exist potential causes of defects as oxygen inclusions. This paper represents a summary of the beginnings of a wider research that will address the problems of gating systems in investment casting technology. In general, the influence of the melt flow is underestimated and the aim of the whole scientific research is to demonstrate the significant influence of laminar or turbulent flow on the resulting casting quality. Specifically, the paper deals with the analysis of the most frequent types of defects found in castings made of expensive types of materials casted in an open atmosphere and demonstration of connection with the design of gating systems in the future.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Use of satellite data in monitoring of hydrophysical parameters of the baltic sea environment
Autorzy:: Krężel, A.
Bradtke, K.
Herman, A.
Tematy:: satellite remote sensing
Baltic
SST
solar energy
sea ice
oil spill; Pokaż więcej
Wydawca:: Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:: https://bibliotekanauki.pl/articles/259766.pdf Link otwiera się w nowym oknie
Opis:: Intensive development of infrastructure for fast processing of outsized amount of space-borne data enables now to use the satellite data for operational controlling the state of its environment. In our presentation we show some examples of analysis of processes in marine environment which are possible due to satellite data and algorithms of its processing developed in SatBaltic Project. It concerns supporting of modelling of solar energy inflow to the sea with space-borne input data, identification and analysis of sea ice cover, supporting of oil spill detection, and identification of phenomena which modify spatial distribution of the sea surface temperature.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Wind wave climate of West Spitsbergen: seasonal variability and extreme events
Autorzy:: Wojtysiak, K.
Herman, A.
Moskalik, M.
Tematy:: wave climate
wind wave
atmospheric circulation
seasonal variability
extreme event
Svalbard
West Spitsbergen; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/2079303.pdf Link otwiera się w nowym oknie
Opis:: Waves are the key phenomenon directly influencing coastal morphodynamics. Facing insufficient observations, wind wave climate of the west coast of Spitsbergen can be characterized on the basis of the modelled data. Here we have used the results of spectral wave models: Wave Watch III (WW3) hindcast and WAM in ERA-interim (ERAi) reanalysis. We have observed the presence of seasonal cycle with difference of up to 1 m between significant wave heights in summer and winter. In wave-direction analysis we have noticed the southwestern swell component of remarkably narrow width, thus we expect unidirectional swell impact on the coastline. Extreme events analysis revealed that storms occur mainly in winter, but the most energetic ones (significant wave height of up to 9.5 m) occur in spring and autumn. We have identified positive trends in storms’ frequency (2 storms per decade) and storms’ total duration (4 days per decade) on the south of the study area. More storms can result in the increase of erosion rate on the south-western coasts of Spitsbergen, but this change may be highly dependent on the sea ice characteristics. Wave heights of wind sea and swell are correlated with the relevant atmospheric circulation indices, especially the North Atlantic Oscillation. In the recent decade, the correlation is stronger with WW3 than with ERAi data, at some locations explaining over 50% (over 30%) of the total variance of wind sea (swell) wave heights. In ERAi data, the relationship with circulation indices seems sensitive to the length of the analysis period.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: New Use of Instruments for More Accurate Wax Pattern Blade Segment Production
Autorzy:: Herman, A.
Kubelková, I.
Vrátný, O.
Tematy:: foundry industry
application of information technology
innovative foundry technologies
innovative materials
Investment casting
gas turbines
infrared thermography
simulation
przemysł odlewniczy
zastosowanie technologii informatycznej
innowacyjne technologie odlewnicze
innowacyjne materiały
turbiny gazowe
symulacja; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/381106.pdf Link otwiera się w nowym oknie
Opis:: Precision casting is currently motivated by high demand especially for castings for the aerospace, automotive and gas turbine industries. High demands on precision of this parts pressure foundries to search for the new tools which can help them to improve the production. One of these tools is the numerical simulation of injection process, whereas such software especially for investment casting wax injection, process does not exist yet and for this case must be the existing software, for alloys or plastic, modified. This paper focuses on the use of numerical simulations to predict the behavior of injected models of gas turbine blades segments. The properties of wax mixtures, which were imported into the Cadmould simulation software as a material model, were found. The results of the simulations were verified using the results of 3D scanning measurements of wax models. As a supporting technology for verifying the results was used the Infrared Thermography.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Monitoring of Manufacture Stability of Large Turbine Blades Using Infrared Thermography (IRT) in Investment Casting Technology
Autorzy:: Herman, A.
Vrátný, O.
Kubelková, I.
Tematy:: casting defect
product development
investment casting
wax pattern
turbine blade
infrared thermography
wada odlewu
rozwój produktu
odlewnictwo precyzyjne
model woskowy
łopatka wirnikowa
termografia w podczerwieni; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/381486.pdf Link otwiera się w nowym oknie
Opis:: With increasing technology development, an increasing emphasis is placed on the precision of products, but cannot be guaranteed without a stable production process. To ensure the stability of the production process, it is necessary to monitor it in detail, find its critical locations and eliminate or at least control it. With such a precise manufacturing method as investment casting, such a process is a must. This paper therefore deals with monitoring the production process of wax models of large turbine blades using infrared thermography. The aim was to evaluate the critical locations of this production and to propose recommendations for their elimination or, at the very least, significant mitigation of their impact on the final quality of the large turbine blade casting.
Dostawca treści:: Biblioteka Nauki

Artykuł

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Skocz do pozycji: 9.

Tytuł:: The deformation of wax patterns and castings in investment casting technology
Autorzy:: Herman, A.
Česal, M.
Mikeš, P.
Tematy:: technologia informatyczna
przemysł odlewniczy
innowacyjne technologie odlewnicze
innowacyjne materiały odlewnicze
odlewanie precyzyjne
model odlewniczy
information technology
foundry industry
innovative foundry technologies
innovative foundry material
investment casting
wax patterns; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/382400.pdf Link otwiera się w nowym oknie
Opis:: The dimensional accuracy of the final casting of Inconel alloy 738 LC is affected by many aspects. One of them is the choice of method and time of cooling wax model for precision investment casting. The main objective was to study the initial deformation of the complex shape of the casting of the rotor blades. Various approaches have been tested for cooling wax pattern. When wax models are cooling on the air, without clamping in jig for cooling, deviations from the ideal shape of the casting are very noticeable (up to 8 mm) and most are in extreme positions of the model. When blade is cooled in fixing jig in water environment, the resulting deviations compared with cooling in air are significantly larger, sometimes up to 10 mm. This itself does not mean that the final shape of the casting is dimensionally more accurate with usage of wax models, which have deviations from the ideal position smaller. Another deformation occurs when shell mould is produced around wax pattern and furthermore deformations emerge while casting of blade is cooling. This paper demonstrates first steps in describing complex process of deformations of Inconel alloy blades produced with investment casting technology by comparing results from thermal imagery, simulations in foundry simulation software ProCAST 2010 and measurements from CNC scanning system Carl Zeiss MC 850. Conclusions are so far not groundbreaking, but it seems deformations of wax pattern and deformations of castings do in some cases cancel each other by having opposite directions. Describing entirely whole process of deformations will help increase precision of blade castings so that models at the beginning and blades in the end are the same.
Dostawca treści:: Biblioteka Nauki

Artykuł

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Skocz do pozycji: 10.

Tytuł:: Development of a New Tool Material for High Pressure Die Casting
Autorzy:: Herman, A.
Zikmund, P.
Tatíček, F.
Tematy:: innovative foundry technology
innovative foundry material
metallography
die material
HPDC technology
wear resistant alloy
innowacyjna technologia odlewnicza
innowacyjny materiał odlewniczy
metalografia
odlewanie ciśnieniowe
stop odporny na ścieranie; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/382710.pdf Link otwiera się w nowym oknie
Opis:: The paper describes existing requirements for tool materials. In the light of experience with these supplied materials, we have demonstrated their considerable influence on the life of molds for die casting technology. From this research came the evaluation methodology of these tool materials which has been used for directing the development of a new material. Based on the new regulation of the chemical composition a sample was casted and forged after that. Then was determined the process of heat treatment and from a block of this material a mold insert was produced. This insert is now being tested in production.
Dostawca treści:: Biblioteka Nauki

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