Applied Engineering Letters

1-5

Authors: P. Boryło, K. Matus, K. Lukaszkowicz, M. Szindler, K. Gołombek

In recent years a growing interest in searching new material for producing Transparent Conductive Layers (TLC) is observed. ZnO:Al thin films are this type material, interesting due to wide range of potential applications where it can be applied like: transparent electrodes, gas sensors, thin film transistors, sensor devices, electroluminescent diodes and others. The aim of this paper is to discuss influence of the ZnO:Al film deposition parameters of PVD magnetron sputtering method on TCL structure and its chemical composition. It contains description of the ZnO:Al PVD magnetron sputtering deposition method. It discusses results obtained from the analysis of the microstructure of ZnO:Al thin films using a high resolution scanning electron microscope, layers' surface topography determined with atomic force microscope and results of chemical composition analyses.

11-15

Authors: J. I. Cifuentes

In this study, the effect of surface modification of aluminum powders on wear and the fracture mechanics behaviors of aluminum/epoxy composites was investigated. Aluminum powders were surface-modified with 3- aminopropyltriethoxysilane. Aluminum/epoxy composites were fabricated by the cast molding method using 10% wt. untreated and silane-treated aluminum powders. Tensile, Mode I fracture and wear tests were performed on both composites. The results showed that the tensile modulus and strength of silane-treated aluminum/epoxy composites were 20% and 30% greater, respectively than those of untreated aluminum/epoxy composites. The results also showed that the fracture toughness and wear resistance of silane-treated aluminum/epoxy composites were ~25% and ~75% greater than that of untreated aluminum/epoxy composites. The scanning electron microscope (SEM) examination showed that the improvement of tensile and fracture properties of silane-treated aluminum/epoxy composites were attributed to the improved dispersion and bonding of aluminum particles in the epoxy, due to the silanization of aluminum powders.

22-26

Authors: K. Matuš, K. Gołombek, P. Palček, P. Boryło

The aim of the article was to identify and characterize the precipitates formed in the aluminum alloys with the addition of antimony. The performed investigation was on the casting aluminium alloy based on ENACAlMg5Si2Mn (ENAC-51500) used in the automotive industry with the addition of antimony in an amount of 0.2 % for the first sample and 1.2 % for the second one. The main research technique was scanning electron microscopy, in order to evaluate the morphology and precipitates in the investigated samples, the backscattered electrons were used. Performed research allowed to determine the effect of the addition of antimony on the morphology of formed precipitates.

32-37

Authors: M. Mazur, R. Ulewicz

The article presents the preliminary tests results of three high-strength steels, which are used in structural elements of semi-trailer's construction. Paper presents an analysis of tensile and fatigue test results of high-strength steels like Hardox 400, Hardox 450 and Strenx 700MC. The fatigue tests are in the range from 104 to 107 number of cycles of applied load with a frequency of 40 Hz. The Wöhler curve shows the results of the fatigue properties of these steels, which are used in the construction of vehicles.Fatigue fractures were subjected to fractographic analysis in order to determine the mechanism of fatigue crack propagation. Fractographic analysis confirmed no effect of inclusions on the test results.

43-47

Authors: Ł. Reimann

The aim of this work was to compare the level of protection of spontaneous and electrochemical passivation of the CoCr alloy against corrosion in environment simulating the conditions prevailing in the mouth. Passivation layer was obtained as spontaneous in air at 23 °C for 1 and 24 hours and by electrochemical method by polarization at potentials 0 and 100 mV for 1 and 24 hours. The corrosion resistance tests was realized by potentiodynamic method in Fusayamya saliva solution. Based on realized research it was concluded that electrochemical passivation better protects material from corrosion than passivation in air; extending the electrochemical passivation time results in greater corrosion resistance and higher passivation potential and longer time was related to formation of a thicker protective layer on the material's surface.

54-59

Authors: T. Tański, W. Matysiak, P. Witek

Iron oxide nanoparticles have a wide range of properties and a lot of applications in today nano-world. They can be used as: catalyst system [1],biomaterials for the tissue engineering [2], good base for magnetic nanoparticles – to locate hyperthermia, membranes for water purification or thermal energy storage. Poliacrylonitrile, although thermoplastic, is also rigid and brittle and used in manufacturing of synthetic fibers. The most useful applications of nanofibers reinforced by the Fe2O3 nanoparticles are in catalyst systems. Space between nanofibers is so small that all impurities are stopped and removed. In water treatment plants,chrome is the main element to be removed, because of its noxiousness to humans. The aim of this study was to fabricate composite nanofibers reinforced by the Fe2O3 nanoparticles with a polymer matrix of polyacrylonitrile (PAN) by the method of the solution electrospinning. After the production, morphology and structure were analyzed on scanning electron microscope; optical properties were analyzed by UV-VIS spectroscopy.