Investigation of dissipative properties of liquid crystalline lubricant layer

This work aims to investigate vibration behavior of rotating roller - a fixed segment friction pair lubricated with pure motor oil and motor oil containing liquid crystal (cholesteryl oleate) additive. Experiments were performed under boundary friction conditions. Mechanical vibrations were registered through the processing and analysis of radial vibration data of the segment, obtained for each lubricant composition under constant roller speed. It is established that vibration level of the segment is reduced at the presence of liquid crystal additive. Theoretical investigations of load-carrying properties of individual layered liquid crystal in a lubricating gap of the film lubrication bearing show a strong increase in load as compared with the equivalent viscous lubricant

Investigation of modal shapes of the alignment-leveling table

This paper focuses on the assessment of modal forms of the alignment leveling table and their impact to the angle measurement accuracy of circular scales. It also addresses the impact of the experimental stand structure to the measurement of these scales. Even though the performed investigations are used to determine the precision of a specific angle measurement system, the findings do have a wider range of applications and can be used for the development of precision measurement instruments. Experimental and numerical investigations are used to illustrate the efficiency and effectiveness of the proposed alignment-leveling table

Investigation of modal shapes of the alignment-leveling table

This paper focuses on the assessment of modal forms of the alignment leveling table and their impact to the angle measurement accuracy of circular scales. It also addresses the impact of the experimental stand structure to the measurement of these scales. Even though the performed investigations are used to determine the precision of a specific angle measurement system, the findings do have a wider range of applications and can be used for the development of precision measurement instruments. Experimental and numerical investigations are used to illustrate the efficiency and effectiveness of the proposed alignment-leveling table

Investigation of modal shapes of the alignment-leveling table

This paper focuses on the assessment of modal forms of the alignment leveling table and their impact to the angle measurement accuracy of circular scales. It also addresses the impact of the experimental stand structure to the measurement of these scales. Even though the performed investigations are used to determine the precision of a specific angle measurement system, the findings do have a wider range of applications and can be used for the development of precision measurement instruments. Experimental and numerical investigations are used to illustrate the efficiency and effectiveness of the proposed alignment-leveling table

Combined Effect of CrB2 Micropowder and VN Nanopowder on the Strength and Wear Re-sistance of Fe‒Cu–Ni–Sn Matrix Diamond Composites

The paper presents research results on the enhancement of diamond composites designed for tools application for mining industry, hard rocks cutting, able to withstand harsh conditions under heavy dynamical loads. In the present study, both CrB2 micropowder and VN nanopowder additives were used in proportions up to 5 wt.% and 6 wt.%, respectively, together with the basic matrix composition of 51 wt.% Fe, 32 wt.% Cu, 9 wt.% Ni, and 8 wt.% Sn. Addition of both components, CrB2 and VN, appeared to be ad-vantageous in proportion of 2 wt.% and 4 wt.%, respectively. This composition exhibited the highest relative density of 0.9968, better than that without additives. Similarly, the highest values of compressive strength Rcm and flexural strength Rbm were reached for the composite with the same percentage of CrB2 and VN. Compared to the composite with no addition of CrB2 and VN, Rcm improved by almost 70%, while Rbm by 81%. Additionally, the abovementioned additives enhanced the ability of the matrix to prevent the diamond reinforcement from being torn out of the composite, which is very important under harsh working conditions of the cutting tools. The presence of CrB2 micropowder and VN nanopowder promoted densification of the matrix and adhesion between the diamond grits and the Fe‒Cu–Ni–Sn matrix