Tag Archives: strength

1257-1265 M. Tichý, M. Müller, P. Valášek and I. Miturska
Effect of rubber powder from waste tyre rubbers on mechanical properties of one-component polyurethane putty
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Effect of rubber powder from waste tyre rubbers on mechanical properties of one-component polyurethane putty

M. Tichý¹*, M. Müller¹, P. Valášek¹ and I. Miturska²

¹Czech University of Life Sciences, Faculty of Engineering, Department of Material Science and Manufacturing Technology, Faculty of Engineering, Kamýcká 129, CZ165 21 Prague, Czech Republic
²Lublin University of Technology, Department of Production Engineering, Mechanical Engineering Faculty, Nadbystrzycka 36, PL20 618 Lublin, Poland
*Correspondence: xticm001@studenti.czu.cz

Abstract:

The utilization of adhesives in technical practice is varied. Adhesives serve for a creation of strength bonds on the one hand, and on the other hand e.g. for cementing. The aim of the research is a modification of one-component polyurethane putty RPS 45 used in automotive industry to increase strength properties in an adhesive bond. An interaction between a filler in the form of rubber powder micro-particles and one-component polyurethane adhesive was investigated by means of SEM analysis. Sealing is a primary property of this putty. Sealing putties usually reach very small strength which can be increased by an admixture of the filler. In order to keep elastic properties, micro-particles of the rubber powder gained from tyre recycling process were used as the filler. An aspect of a loading speed of the adhesive bond is essential at the practical application at which the adhesive bond can be failed in adhesive or cohesive layers. The adhesive bond can be perceived in terms of its function as a complex of three layers, i.e. an adhesive bonded material, the interaction between the adhesive and the adhesive bonded material and the adhesive layer itself. There are often states in the practices when the adhesive bonds are exposed to the loading which can be either a static or a dynamic one. That is why the research is focused not only on the evaluation of the influence of the modification of the one-component polyurethane adhesive, but also on the influence of the loading speed of the adhesive bond. Tested speeds set on a universal testing machine Zwick/Roell Z150 were 2, 50 and 100 mm min-1. The results of mechanical tests proved a positive influence of the filler on the strength σm higher by 42.68 ± 6.96% and the elongation at break εb higher by 12.2 ± 20.95%. On the contrary, the stress at yield σy was decreased.

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1107–1118 M. Müller
Mechanical properties of resin reinforced with glass beads
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Mechanical properties of resin reinforced with glass beads

M. Müller

Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences, Kamýcká 129, CZ165 21 Prague, Czech Republic
Correspondence: muller@tf.czu.cz

Abstract:

The research was focused on the evaluation of a loading speed and a size of the particle filler in a form of glass beads B159 and B112 on resultant behaviour of a composite material and during its application in a structural adhesive bond. A fall of the tensile strength of the composite material of ca. 60% is obvious from the experiment results when adding both fillers (B159 as well as B112). This composite material showed in the positive way as the adhesive at the adhesive bonds. The experiment results proved the positive influence of adding the particle filler of the spherical shape – glass beads B159 (the fraction size 85.23 ± 31.23 μm) on the adhesive bond strength. The adhesive bond strength was increased up of 14% at the filler glass beads B159. However, adding the filler into the resin proved that this filler eliminated the influence of various loading speeds. Adding the filler into the resin changed a fracture surface. An analysis of a scanning electron microscopy (SEM) proved a good wettability of the filler, the resin and the adhesive bonded material (a structural carbon steel S235J0). A crack propagation was concentrated around the filler B112 (151.59 ± 53.04 μm), namely at higher value of the loading speed, i.e. 10 mm min-1. The crack propagation is a consequence of this. Higher particles show in a negative way namely at an initiation of the fracture surface.

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1043–1052 V. Maksarov, A. Khalimonenko and J. Olt
Effect of porosity on the performance of cutting ceramics
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Effect of porosity on the performance of cutting ceramics

V. Maksarov¹*, A. Khalimonenko¹ and J. Olt²

¹Saint-Petersburg Mining University, 21st Line 2, 199106 St. Petersburg, Russia
²Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56, ЕЕ51014 Tartu, Estonia
*Correspondence: maks78.54@mail.ru

Abstract:

 The article examines the forecasting performance of the cutting tool equipped with interchangeable plates of carbide oxide ceramics (A2 – mixed ceramic), by definition porous ceramic tool material affecting its cutting properties. Set correlation of porosity ceramic tools from electrical resistivity removable ceramic plates. Cutting tools having larger electrical resistivity values and, respectively, smaller porosity percentages should be used for machining the most precise components of machine part blanks, since their performance will be better than that of the tools whose ceramic bits have small electrical resistivity values. Based on the established correlation selects ceramic plates for the required machining conditions.

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