December 2008

Criterion C –Based evaluation of the topography of abrasive waterjet – produced surfaces

MM (Modern Machinery) Science Journal, December 2008
J. Valicek1, S. Hloch2, P. Hlavacek3, M. Drzik4, M. Kusnerova1, R. Cep3
1Institute of Physics, Faculty of Mining and Geology, VSB-Technical University of Ostrava, Czech Republic
2Department of Technology Systems Operation, Faculty of Manufacturing Technologies, Technical University of Kosice with the seat in Presov, Slovakia
3Department of Machining and Assembly, VSB-Technical University of Ostrava, Ostrava, Czech Republic
4Institute of Construction and Architecture, Slovak Academy of Sciences, Bratislava, Slovakia

In the contribution we present the utilization of criterion C for the evaluation of topography of metallic materials surfaces generated by the abrasive waterjet. The criterion C provides a realistic picture of the proportion of waviness (low-frequency irregularities) to the total number of surface irregularities. The critical value of parameter Cc = 0.66 was determined experimentally for metallic materials. This value differentiates the surface into two morphologically different zones. The first zone, which is there in the upper part of the cut, is characterised by the absence of conspicuous striations, and thus is considered to be of good quality. The other zone is characterised by conspicuous striations and thus is taken as a zone of poor-quality. The parameter C can also be used in the classification of materials by machinability.

Keywords: abrasive waterjet, surface roughness, optical measurement
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Qualitative consequences in finishing process of holes grinding into ceramics with the high power ultrasound application

MM (Modern Machinery) Science Journal, December 2008
Pechacek Fr., Charbulova M., Javorova A.
Slovak Univerzity of Technology in Bratislava,
Faculty of Material science and Technology in Trnava, Slovak Republic

The paper deals with qualitative changes of machining of holes in ceramic materials applying by finishing conventional grinding and high power grinding. Measured and determined values of surface roughness of machining material definitely indicated the advantages of high power ultrasound application. Ultrasound grinding is the technological method of grinding useful for hard machinable materials.

Keywords: high power ultrasound, ultrasound system, ultrasonic spindle, roughness, technical ceramics, hard machined materials
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This paper was presented at workshop Applied Engineering Design Science AEDS 2008, Pilsen

Technical products and their attributes – theory and practical applications
This paper has been presented at workshop applied engineering design science AEDS 2008 held in Pilsen

MM (Modern Machinery) Science Journal, December 2008
Hosnedl St., Srp Zb., and Dvorak J.
University of West Bohemia, Faculty of Mechanical Engineering
Department of Machine Design, Pilsen, Czech Republic

Any technical product – technical system (TS) and its life cycle processes need to meet many requirements. These are not only requirements concerning the TS operation functions, their parameters and connection interfaces, but also high product safety and health protection, good appearance, easy manufacture, transport, maintenance and liquidation, low price, short delivery time, and many others. The paper introduces a system approach based on the “Map” of Engineering Design Science knowledge [Hubka&Eder 1988, Hubka&Eder 1996, Andreasen 2000, Eder&Hosnedl 2008, and many others] the aim of which is to achieve a higher transparency and user friendliness of the outlined and bounded engineering design areas, and shows practical applications, which have quite successfully validated the proposed improvements.

Keywords: Technical Product, Attributes, Characteristics, Properties, Behaviour, Values, Requirements
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