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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Validace numerické simulace průběhu plnění matečné formy voskem a její následná optimalizace / Validation of numerical simulation of wax filling into mother die followed by its optimization

Bochníček, Štěpán January 2013 (has links)
The main topic of the diploma thesis is simulation of the process when wax is filling the cavity of the "mother" metal die.This knowledge is the neccessary presumption for correct design of the gating system and setting correct injection parameters (temperature, pressure, wax flow) when making wax patterns.
12

Optimalizace technologie výroby odlitků ze slitin Al metodou vytavitelného modelu / Optimization of manufacture of aluminium castings by using lost wax technology

Soukupová, Lucie January 2013 (has links)
Diploma thesis is focused to the optimization of the ceramic shell for pouring thin walled aluminium castings by investment casting technology. The main objective is firstly to find the optimal binding system (ceramic slurry) and stucco materials for the shell and secondly its optimal structure and heat treatment (drying of each coat and final shell firing) before metal pouring.
13

Nové frézovací nástroje z rychlořezné ocelí pro hrubovací operace / New Milling HSS Cutters for Roughing Operations

Jaroš, Aleš January 2015 (has links)
Dissertation thesis is focused on development, design and production of the new milling cutter which is used for roughing operations. High-speed steels, coating technology and milling technology are described in first chapters of dissertation thesis. The main part of this thesis is the design of the new milling cutter that has been designed on the basis of the machining simulation. The milling cutter is designed as a three-flute cylindrical end mill made of high speed steel. The each flute is composed of two special compensation edges. The compensation edges are used for reducing (at best suppression) tensile stress in the heel of the tooth. The milling cutter was made by lost wax technology, followed by grinding and thermal treatment. New designed tools were deposited by PVD coatings (e.g. (Al,Ti)N). Standard catalog milling cutters (producer ZPS - milling tools, Zlín, Czech Republic) were used for comparison the designed milling cutter. Carbon steel CSN 41 2050 (DIN 1.1191) was used for milling, which was carried out with using process liquid. The monitored parameters were force loading, flank wear and tensile stress during milling. The dynamometer Kistler was used for measuring force loading and data obtained during machining was used for stress analysis.
14

Optimalizace technologie výroby voskových modelů ve firmě Fimes / Optimization of wax pattern technology in the company Fimes

Žuja, Jaroslav January 2015 (has links)
This thesis is to evaluate currently used wax and compare its properties with of newly purchased one. Further, it is to evaluate whether the quality is reflected by using "boiled wax'', which is being used as a runner wax. All tests were carried out at the Fimes a. s. In the first part of this thesis, there is a brief description of the lost wax method. This is followed by a decription of wax blends from technology point of view. The experimental part describes the operations from the production of wax patterns, through their dimensional inspection, up until dewaxing process. All the results are noted and compared.
15

Comparison of different aluminium casting processes from an environmental perspective : Case study on plaster mould castings produced in Mid Sweden

Schaub, Henning January 2018 (has links)
While Aluminium has lots of unique properties and is seen as a material of the future, its production and manufacturing has significant environmental impacts. For complex and dimensional shapes casting remains the main manufacturing method and in this study the environmental pressure of different casting techniques is compared. A screening LCA is conducted to determine the environmental impacts of plaster mould castings in a case study at the Ventana Hackås AB foundry in Mid Sweden. The findings are compared to models of sand, pressure die and lost wax castings, based on literature datasets. The most relevant factors for the environmental performance are identified as the production of the aluminium alloy and the amount and source of energy. For plaster mould castings additionally the plaster consumption is significant, while lost wax castings are dominated by the mould production and general processes. Under similar circumstances a relatively similar performance was found for all casting techniques except the lost wax process, which is at least 3 times more emission intensive. Of the remaining techniques pressure die castings performed the best and plaster mould castings the worst, but different sources of uncertainties have been identified in this comparison. In addition a carbon footprint interface is created based on these findings, to enable specific comparisons of different casting method setups. Customizable variables allow the adaptation of three scenarios to real world conditions. As the main influencing factors the aluminium alloy, source of electricity and casting technique have been identified. / <p>2018-10-10</p>
16

Optimalizace technologie vybraných náročných odlitků ze slitin Al / Optimation of manufacturing technology of high value castings

Šmíd, Dušan January 2009 (has links)
The main target of this thesis is to choose the suitable hard filled wax for the invest-ment casting foundry Fimes a.s. There are several suppliers of these waxes in the World and in this work waxes of the most reputable suppliers from Europe have been investigated. During these tests there were mainly technological properties of the waxes and also dimensions of both wax patterns and also the final castings measu-red. Suitability of the tested waxes, their technological characteristics, analysis of di-mensions and finally basic economical calculations have been then used in this the-sis as a tool for the recommendation for the most suitable wax for the Fimes foundry.
17

Optimalizace technologie výroby odlitků ze slitin Al metodou vytavitelného modelu / Optimized manufacturing of aluminium castings by using lost wax technology

Talanda, Ivan January 2012 (has links)
Aim of this diploma thesis is to choose new pattern wax for Fimes a.s. foundry. New wax should substitute old not fully satisfactory pattern wax which caused problems in technological process resulting in increased number of rejects. New pattern wax should eliminate current problems and help foundry with producing large, thin-walled, high-quality castings. Numbers of pattern waxes supplied by world’s leading wax manufacturers were subjected to laboratory tests and pilot study. This diploma thesis is part of project Alfa TA01010766: „Research and development of production technology large, thin and high quality castings of aluminium alloys “
18

Optimalizace technologie voskových modelů ve firmě Alucast / Optimization of wax pattern technology in the company Alucast

Šmatelka, Jakub January 2014 (has links)
This diploma thesis deals with the problem of wax patterns manufacturing in investment casting technology (lost wax process). This technology is very sensitive to the exact execution in each phase of the whole process, from concept design up to the final casting expedition. During most operations, dimensional changes occur, which is affecting the accuracy of the final casting. No matter how big these changes are, but especially if they occur with the least variance. One of the first phases in this technology is making wax patterns. There are several ways of making the wax patterns and this thesis is describing two different methods used in the Alucast foundry. One is based on using “soft waxes” enabling using low pressure machines, the other one on the “hard waxes” where the injection machine with higher presses is being used (SOM). These two above mentioned technologies are compared in this work.

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