Wyniki wyszukiwania - BazTech

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Vibration analysis during AZ31 magnesium alloy milling with the use of different toolholder types

Korpysa Jarosław, Zagórski Ireneusz

Eksploatacja i Niezawodność

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2022

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Vol. 24, no. 3

489--501

EN

Machining vibrations are an important issue as they occur in all types of machining processes. Due to its negative impact on machining results, this phenomenon is undesirable, and so there have been continuous efforts to find solutions that will minimise it, and thus improve the stability and safety of the machining process. The paper attempts to determine the impact of toolholder type and cutting condition on the vibrations generated while milling an AZ31 magnesium alloy. The tests were performed using the three most common types of toolholders: ER, Shrink Fit and hydraulic. The vibration displacement and acceleration signals were analysed based on parameters such as Peak-to-Peak, Peak, and Root Mean Square. Composite Multiscale Entropy was also applied to check the stability of cutting processes and define the level of signal irregularity. To determine the frequencies of vibrations and to detect chatter vibrations Fast Fourier Transform was performed. This provides information on the stability and enables vibrations to be minimized by avoiding unfavourable cutting conditions.

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Process ambidexterity in startups innovation

Korpysa Jarosław

Management Systems in Production Engineering

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2021

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nr 1 (29)

27--32

EN

The article is of theoretical and empirical character. The main objective is to identify certain conditions related to the innovative ambidexterity of Polish startups. The objective implementation protocol of the study determined its structure. Its first part presents the most important theoretical concepts related to the presented issues. In particular, on the basis of the literature on the subject, analyses of the innovative ambidexterity. Moreover a start-up was equated with a company operating no longer than a year, which offers an innovative solution. Theoretical considerations provided the basis for the empirical presentation of the results of the author's own research conducted in 2019 in Poland on startups. On the basis of the outcome it has been established the most important factors determining innovative ambidexterity in startups are: having access to external source of financing and to external infrastructure as well as the acquisition of a license/patent. Moreover it has been diagnosed that create innovation and simultaneously reduce in startups the tension between exploitation and exploration activities to a large extent rely on external sources when implementing their innovation processes. For the theory on management, the theoretical-empirical deliberations presented in the article may be a valuable source of information within the scope of the influence the particular elements of innovative ambidexterity have on startups. However, for entrepreneurs they may be an impulse in the field of effective use of the innovative ambidexterity in the process of building competitiveness of young companies in Poland.

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Surface Quality in Milling of AZ91D Magnesium Alloy

Zagórski Ireneusz, Korpysa Jarosław

Advances in Science and Technology. Research Journal

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2019

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Vol. 13, no 2

119--129

EN

This paper is an attempt at determining the effect of technological parameters of milling on the surface roughness of the AZ91D magnesium alloy. The cutting tool used in tests was a TiAlN-coated carbide milling cutter. The milling tests were carried out at variable cutting speed, feed per tooth and depth of cut, and the results were compared. The analysis was based on the 2D roughness parameters measured on the end and lateral faces of specimens, as well as on the 3D roughness parameters measured on the end faces of specimens. The test results indicated that the increase in the feed per tooth results in the increase in the value of 2D and 3D surface roughness parameters. It was found that cutting speed and axial depth of cut have a negligible effect on the 2D roughness of the workpiece surface, whereas the increase in cutting speed results in the reduction of the 3D surface roughness parameters.