Tag Archives: abrasive wear

758-768 A. Kešner, R. Chotěborský, M. Linda and M. Hromasová
Using the FEM model for design the heat treatment of an agricultural tools
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Using the FEM model for design the heat treatment of an agricultural tools

A. Kešner¹*, R. Chotěborský¹, M. Linda² and M. Hromasová²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of Material Science and Manufacturing Technology, Kamýcká 129, CZ165 21 Prague, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Eletrical Engineering and Automation, Kamýcká 129, CZ165 21 Prague, Czech Republic
*Correspondence: kesner@tf.czu.cz

Abstract:

Agricultural tools need mechanical properties such as abrasive wear, hardness and toughness. These mechanical properties are achieved by choosing a suitable steel and subsequent heat treatment of the steel. Phases of the microstructure affects the final steel properties. The phase composition in the steel is influenced with the designing of the heat treatment. 25CrMo4 steel was investigated for the production of agricultural tools. The heat treatments ware designed for different cooling conditions. The salt bath was used to cooling as a medium with subsequent cooling on the water or in the air. The FEM method was used to designing the heat treatment conditions. The Johnson-Mehl-Avrami-Kolmogorov equation and the Koistinen-Marburger equations were used to prediction the microstructure phases. The microstructures were verified with experimental measurements. The ASTM G65 method was using for abrasion resistance tests. The results show that this procedure can be used to designing parameters of heat treatment of agricultural tools.

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1242–1250 P. Valášek and K. Habrová
Influence of sisal fibres on tribological properties of epoxy composite systems
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Influence of sisal fibres on tribological properties of epoxy composite systems

P. Valášek* and K. Habrová

Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences Prague, Kamýcká 129, CZ16521 Prague, Czech Republik
*Correspondence: valasekp@tf.czu.cz

Abstract:

Composite are materials, which synergically combine properties of the matrix and fillers. An interaction of polymers – resins – with biological kind of fillers can optimize their mechanical properties in the same way as synthetic fillers. Biological fillers have many advantages, which include low price and satisfying mechanical properties. Significant disadvantages are different properties of fibers – for example, fibre diameter and strength – which are caused by the biological essence of this material. The design of new composite materials based on natural renewable resources is essential for an environment and is also attractive from an economic point of view. This paper describes the hardness and resistance to abrasive wear of epoxy resins filled with unordered short sisal fibers (3, 6 and 9 mm). Scanning electron microscopy was used to assess the fibers and interaction between fibers and epoxy resin.

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247-254 R. Chotěborský, and M. Linda
Evaluation of friction force using a rubber wheel instrument
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Evaluation of friction force using a rubber wheel instrument

R. Chotěborský¹,* and M. Linda²

¹Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences, Kamýcká 129, 6521 Prague 6, Czech Republic; *Correspondence: choteborsky@tf.czu.cz 2 Department of Electrical Engineering and Automation, Faculty of Engineering, Czech University of Life Sciences, Kamýcká 129, 16521 Prague 6, Czech Republic

Abstract:

Abrasive wear is the most important process for innovation of new materials in agriculture. The method depends on the internal (the microstructure of the abraded material) and external (characteristic of the abrasive particle, force, etc.) conditions. A modified rubber wheel instrument based on the ASTM G65 procedure was used to obtain the study results. The results showed that the friction between an abrasive particle and abraded material was influenced by the microstructure of the abraded material and this relationship can be used for abrasive wear evaluation. The study result also showed that the limitation of using the rubber wheel method was the natural frequency of the system. In this study, the natural frequency was found to be 200 Hz, which is useful for elimination of the algorithm for frequency and amplitude during wear analysis.

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