Uniaxial tension of drying sieves

Although the literature contains numerous studies that have been developed to describe the nonlinear behavior of drying sieves' operation, there are no papers in this which report deeper investigation of the drying sieve behavior when exposed to tension and thermo stabilization. The aim of this paper is to provide insight into the elastoplastic behavior of the thermo stabilized and not stabilized sieves subjected to the tensile force. Within this work both theoretical and experimental investigations were performed. The sieves were joined by using a spiral. In separate experiments tests of wire base and weft of the weave mesh were performed, both for thermo stabilized and not thermo stabilized sieves, sieves joining and the sieve thermo stabilization itself. It was established that the thermo stabilization of sieves provides for stability of sieves' dimensions and that open thermo stabilized drying sieve exhibits better mechanical properties and exploitation characteristics then the sieves joining. [Projekat Ministarstva nauke Republike Srbije, br. ON174004: Micromechanics criteria of damage and fracture and br. TR 32036: Development of software for solving the coupled multi-physical problems

Koncept napredne tehnologije izrade specijalne tehnološke opreme za procesnu industriju

The paper deals with the manufacturing technology of refiner plates that are used for preparing the paper pulp in the paper industry. The manufacturing technology consists of casting, heat treatment, machining and balancing. Special attention is given to the selection of materials used for casting of the refiner plate segments, and to defining the appropriate heat treatment in order to make the tools with optimal technical characteristics. Defining the technological parameters for the process of plain grinding of the refiner plate as well as noting the few negative effects occurring during the grinding process are presented in the paper. The paper also pays attention to the influence of machining technology on the micro-surface of the cutting elements, because it has a significant influence not only on the cutting edge but even on the surface quality and the total consumption of energy in the cutting process.U radu je opisana tehnologija izrade diskastih pločastih noževa koji se koriste za pripremu papirne mase - pulpe u industriji papira i celuloze. Tehnologija izrade sastoji se iz lijevanja, toplinske obrade, strojne obrade i uravnoteženja. Naročita pažnja u ovom radu posvećena je definiranju materijala koji se koristi za lijevanje pločastih noževa i projektiranju odgovarajuće termičke obrade kako bi dobili alate potrebnih tehničkih karakteristika. Definiranje tehnoloških parametara za proces ravnog brušenja pločastih noževa i neke negativne pojave u procesu brušenja također su dati u ovom radu. Rad ukazuje na utjecaj tehnologije obrade na mikropovršinu reznih elemenata, a koja ima bitan utjecaj kako na rezni rub tako na kvalitetu površine i ukupan utrošak električne energije u procesu mljevenja

Electrochemical synthesis and corrosion behavior of polyaniline-benzoate coating on copper

Electrochemical polymerization of polyaniline (PANI) coating on copper electrode was performed galvanostatically in the current density range between 0.50 and 1.25 mA cm−2, from aqueous solution of 0.3 mol dm−3 sodium benzoate and 0.2 mol dm−3 aniline. The corrosion behavior of PANI coated copper and copper electrode exposed to 0.5 mol dm−3 sodium chloride solution was investigated by potentiodynamic and electrochemical impedance spectroscopy techniques. It was observed that thin PANI (5 μm) coating had provided efficient protection (∼96%) to copper in 0.5 mol dm−3 sodium chloride solution. Unusual initial impedance behavior to that normally observed with conventional organic coatings was attributed to dedoping of benzoate anions from the polymer coating

Optimizacija procesa lijevanja pomoću regresijske analize primijenjene na kalupljenje dijelova otpornih na habanje

Conducting a comprehensive research of the casting process of wear resistant parts (white hard casting), a significant correlation is established between the technological parameters (temperature, aging time in the mold and coolant flow) and the final product hardness. The fundamental theory of Box-Wilson\u27s gradient method marked the baseline for the foreseen researches. The method defines the coherence of the process parameters, since their dispersion in the examined process is relatively small. Main target of the experiment was a definition of the optimal casting conditions. Therefore the different technological routes are identified and the casting process is modified until the best outcome is achieved. Target function was initially in a hypothesized form, while later on evolved into a consistent form due to the application of experiment-statistics, process optimization and process management based on empirical feedback.Provodeći sveobuhvatno istraživanje procesa lijevanja dijelova otpornih na habanje (lijevanje bijelog željeza), uspostavljena je značajna korelacija između tehnoloških parametara (temperatura, vrijeme starenja u kalupu i protok rashladnog sredstva) i tvrdoće finalnog proizvoda. Osnovna teorija Box-Wilsonove metode gradijenta činila je osnovu za predviđena istraživanja. Ta metoda definira koherentnost parametara procesa budući da je njihova disperzija u ispitivanom procesu relativno mala. Glavni je cilj eksperimenta bila definicija optimalnih uvjeta lijevanja. Stoga su identificirane različite tehnološke rute i modifikacije u procesu lijevanja dok se nije postigao najbolji rezultat. Ciljna je funkcija u početku imala oblik hipoteze, ali je kasnije dobila konzistentan oblik primjenom statističkih podataka dobivenih eksperimentom, optimizacijom procesa i upravljanjem procesom na bazi empirijske povratne veze

Simulation of the casting process - a powerfull tool for enchanced design of the cutting teeth in surface mining

Recent development in the computer simulation technology caused a tremendous influence on a rapid prototyping in casting process. These computational tools facilitate engineering work and urge moulding verification in foundries. Among dedicated software packages the MAGMASoft is selected for availability reasons. Its effectiveness is proved with the simulation of moulding process of the cutting teeth for a bucket wheel excavator Use of MAGMASoft enables a shortcut to a forceful and durable product, without internal cavities and micro-porosity. Such advancement of the moulding process is described in this paper

Possibility of obtaining favorable mechanical properties of materials for machine elements exposed to wearing and abrasion

There are several options for increase resistance to abrasive wear of parts. Inserting the cocoon into the hole of machine part that is exposed to wearing, welding on worn parts, joining by explosion of different materials or obtaining the bi-nzetal and hardening of finished parts by explosion. The results of comparative studies of the properties of wear-resistant steels for the development of parts exposed to abrasion are presented in this paper. Experiment has included the analysis of the properties of explosion hardened steel 120Mn12, as well as the skills of bimetal (50Mn7 + S355). The results show that explosion processing in case of both variants of material lead to the improved resistance of the parts to abrasive wea

Possibility of obtaining favorable mechanical properties of materials for machine elements exposed to wearing and abrasion

There are several options for increase resistance to abrasive wear of parts. Inserting the cocoon into the hole of machine part that is exposed to wearing, welding on worn parts, joining by explosion of different materials or obtaining the bi-nzetal and hardening of finished parts by explosion. The results of comparative studies of the properties of wear-resistant steels for the development of parts exposed to abrasion are presented in this paper. Experiment has included the analysis of the properties of explosion hardened steel 120Mn12, as well as the skills of bimetal (50Mn7 + S355). The results show that explosion processing in case of both variants of material lead to the improved resistance of the parts to abrasive wea