Actual number: 4/2020

ISSN 1339-5017 (Online)

Archive:


No. 2

LASER WELDING OF SELECTED AHSS STEELS

Author: Igor BARÉNYI, Jozef MAJERÍK

Abstract: The paper deal with laser welding of selected AHSS steels with controlled microstructure. DP600 and DP700 steel is selected for experiment and both these AHSS steels are principally described in theoretical part. Samples of DP600 and TRIP700 were welded and then examined by microhardness test and optical micsrostructure study. Finally, the results are comprised to commonly known characteristics of conventional arc welding.

Keywords: laser welding, DP steel, TRIP steel, microhardness, microstructure of HAZ

Vol. 10, 2016, No. 2, p. 1-5

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ROTARY SEAL OF TURBOCHARGER AND THE REASONS OF ITS MALFUNCTIONS

Author: Jozef DOMAN

Abstract: Diesel internal combustion engines intended for cars, but also petrol internal combustion engines are in some cases fitted with turbocharged to increase some effective parameters of the engine and at the same time reducing of the pollutant content in the engine exhaust. Means of transport automobile transport exploit, as part of an internal combustion engine power train, even if the effort to restrict the using of internal combustion engines. Turbocharger as an option supercharge-internal combustion engine apparatus, affects the operation of the internal combustion engine. Rotary seals on the turbocharger of the fault on the consumption of lubricating oil combustion engine. In the case of failure of the turbocharger, it is affected by the ability to accelerate the combustion engine, while increasing smoke emission diesel engine, the consumption of lubricating oil, and other factors that affect accompanying fault turbocharger combined with diesel, petrol engine as well.

Keywords: turbocharger, compressor, oil, rotary seal, turbine, internal combustion engine, impeller, rotor, shaft.

Vol. 10, 2016, No. 2, p. 6-11

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AFM AS AN ADVANCED TECHNOLOGY IN DIAGNOSTICS OF METALLIC MATERIAL PROPERTIES

Author: Erika HUJOVÁ, Vladimír ÁČ, Jozef KASALA, Mária LIČKOVÁ

Abstract: This article deals with the assessment of the atomic force microscopy (AFM) advantages in the diagnosis of metallic materials properties. The advantages of AFM are compared with traditional metallographic procedures and also with the possibilities of scanning electron microscopy (SEM). There are compared the results of measurements on samples of alpha brass CuZn30 in this article. Until at metallographic technique we can obtain information about the macrostructure on microns level, SEM is doing structural microanalysis at the nanometer level and using the AFM brings us possibility to study materials at the atomic level.

Keywords: Atomic Force Microscopy (AFM), material diagnostics, Scanning Electron Microscopy (SEM), nanostructural properties of metallic materials

Vol. 10, 2016, No. 2, p. 12-18

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DIFFERENT TYPES OF GRIPPERS

Author: Milan JUS

Abstract: This paper is dedicated to different types of end parts of (effectors) of industrial robots and manipulators that can be movable arm terminated by the type of applications that are performed by the device. The variety of effector (gripper) also depends on the type of the manipulated object and the actual method of control effector. For a particular type of gripper is made simulation analysis of its activities.

Keywords: robot, effector, gripper, micro-gripper, manipulator.

Vol. 10, 2016, No. 2, p. 19-23

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EVALUATION OF TRIBOLOGICAL PROPERTIES OF HIGH-STRENGTH MATERIAL WITH DEPOSITED CrN LAYER

Author: Mária LIČKOVÁ, Erika HUJOVÁ, Jozef MAJERÍK, František TÓTH, Pavol TÖKÖLY

Abstract: Two basic requirements such as strength of materials and/or material requirements for the lowest mass, must be meet in the development trends of new high-strength material with high tensile strength, with fracture toughness, with ductility, with better energy-efficient, with high security and cheaper production. The highest growth is recorded in TRIP steels and alloys of Maraging - currently among the strongest materials. Availability of the martensitic steels HCM 18 (EU: 1.2709, DIN: X3NiCoMoTi18-9-5, US: 18 Maraging 300) and its features: high strength, hardness, easy workability, nearly zero dimensional changes after heat treatment, designate these steels for their using in highly stressed components in the aerospace, automotive industries, etc. The aim of the article is microstructure evaluation of HCM 18, the roughness of the substrate and selected CrN coating, evaluation of tribological properties (scratch test) and the wear rate (volume loss of material).

Keywords: high-strength material, HCM 18, thin layer, CrN coating, tribological properties.

Vol. 10, 2016, No. 2, p. 24-28

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QUALITATIVE ASPECTS OF MACHINED SURFACES WHEN TURNING OF ALUMINIUM ALLOYS WITH COATED CUTTING INSERT

Author: Jozef MAJERÍK, Igor BARÉNYI, Mária ŠURLÁKOVÁ, Pavol TÖKÖLY

Abstract: The main objective of this experimental scientific study was to examine the effect of the tribological properties of DLC coating on interchangeable inserts on their cutting performance when machining. Completed experiments confirmed the fact that the exchange of the cutting tool used with DLC coating reduces the adhesion of the technological tool-workpiece system and have an impact on the formation and shape of the chips as well as rise-up edge. To analyze the cutting process has been used in several experimental methods such as SEM analysis of wear on the flank VB and rake surface KT of interchangeable cutting inserts. It was also carried out measurements of surface roughness Ra, and cutting resistance using piezoelectric dynamometer Kistler. Examining the shape obtained through debris SEM microscope was as part of completed experiments. It can be assumed that in the case of dry machining of aluminum alloys allow exchange DLC coated cutting tool improved performance of machining.

Keywords: DLC coatings, aluminium alloys, cutting insert, surface roughness, tool wear, cutting forces.

Vol. 10, 2016, No. 2, p. 29-32

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HAZARD FROM ELECTROMAGNETIC RADIATION TO AMMUNITION CONTAINING ELECTRO-EXPLOSIVE DEVICES

Author: Štefan PIVKO

Abstract: Over recent years there has been a significant increase in the use of communications equipment throughout the military and civil environment including all forms of transportation in support of management functions, control of resources and area security. These equipments produce electromagnetic radiation of varying intensity according to their output and antenna gain and are potentially hazardous when used in close proximity to explosive devices which have an installed electrical means of initiation known as electro-explosive devices (EED).

The advice contained in this chapter represents the minimum precautions to be observed in order to prevent hazard to EED resulting from exposure to the radio frequency (RF) environment at frequencies up to 40 GHz. It is intended that this chapter should provide guidance of officials concerned with the storage, movement and processing of EED or stores containing EED and the control of RF equipment which may be used within, or enter, those establishments/vehicles used for these purposes.

Keywords: electro-explosive devices, CF Environment, Assessed cut of Hazard, System Susceptibility, Safe Distance, Management Radios.

Vol. 10, 2016, No. 2, p. 33-38

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