INVESTIGATION OF IMPURITIES IN BRONZE BrO3A3 INFLUENCE ON ITS MECHANICAL PROPERTIES

Abstract

. Problem statement. To investigate the influence of main alloying components Sn, Al on 3… 4% each without taking into account impurities influence, as well as silicon, iron, zinc and lead in Cu-Sn-Al system bronze on its mechanical properties. Purpose. To establish permissible concentrations of silicon, iron, zinc and lead impurities in Cu-Sn-Al system bronze at tin and aluminum content each of 3… 4%. M aterial and methods. Alloys for investigation have been prepared by melting of technical purity primary charge materials in crucib le induction furnace using graphite crucible and charcoal as coating material. Studied alloys mechanical properties have been calculated based on experimental samples tests results during their static expansion and impact bending at room temperature in accordance with actual standards. Microstructural studies have been performed on metallographic specimens prepared by standard methods on optical microscope Neophot-21. Alloys chemical composition control has been carried out using precision analyzer EXPERT 4L on samples cut from club-shaped samples. Estimation of each impurity influence level on mechanical properties has been estimated according to regression coefficients due to system of corresponding linear equations solving by G. Cramer method. Results and discussion. According to research results, in this work permissible concentrations impurities of silicon, iron, zinc and lead in Cu-Sn-Al system bronze have been detected at optimal content of tin and aluminum 3… 4% each. Conclusions. For the first time, alloying components (Sn, Al on 3… 4% each) optimal amount influence without impurities effect, as well as impurities of silicon, iron, zinc and lead in bronze BrO3A3 on its mechanical properties has been established. Practical impl ementation of received regularities for bronze BrO3A3 preparation is the key to obtaining castings with given level of properties.