Precipitation hardening stainless steel 17-7PH with modified chemical composition was heat treated by modified RH950 condition. In this paper is presented the results of tests of microstructure and mechanical properties of precipitation hardened stainless steel 17-7PH with modified chemical composition, heat treated in modificated RH950 conditions. Regression analysis showed which variables are statistically significant in predicting the value of mechanical properties of the steel 17-7PH chemically modified composition.

In this paper, the microstructure of Cu82.3Al8.3Mn9.4 (in wt. %) shape memory alloy after hot and cold rolling was investigated. The Cu82.3Al8.3Mn9.4 alloy was produced by a vertical continuous casting method in the form a cylinder rod of 8 mm in diameter. After the casting, hot and cold rolling was performed. By hot rolling a strip with a thickness of 1.75 mm was obtained, while by cold rolling a strip with a thickness of 1.02 mm was produced. After the rolling process, heat treatment was performed. Heat treatment was carried out by solution annealing at 900 °C held for 30 minutes and water quenched immediately after heating. The microstructure characterization of the investigated alloy was carried out by optical microscopy (OM), scanning electron microscopy (SEM) equipped with a device for energy dispersive spectroscopy (EDS). Phase transformation temperatures and fusion enthalpies were determined by differential scanning calorimetry (DSC) method. The homogenous martensite microstructure was confirmed by OM and SEM micrographs after casting. During rolling the two-phase microstructure occurred. Results of DSC analysis showed martensite start (M s ), martensite finish (M f ), austenite start (A s ) and austenite finish (A f ) temperatures.

Abstract The Au-Ge alloy is useful for bonding applications in microelectronic and optoelectronic packages. Also, recent investigations show that Au-Ge system could present a lead-free solder candidate. The results of characterization of the eutectic alloy from binary Au-Ge system are presented in this paper. Experimental research was done using thermal analysis (differential thermal analysis, DTA) and structural investigation by light optic microscopy (LOM) and scanning electron microscopy with EDS (SEM-EDS). The eutectic temperature of 359 °C was detected using thermal analysis, while eutectic structure was confirmed using microstructural analysis. Obtained results were compared with recent literature references and good mutual agreement was noticed.

Cu-based shape memory alloys have a big commercial potential due to their low cost and excellent properties. Addition of manganese to binary Cu-Al alloy stabilize -phase region and widen it to lower aluminium content and lower temperatures. Further, Cu-Al-Mn shape memory alloys with low degree of order of the -phase show high ductility. In this paper, experimental results on the microstructure of as-cast as well as heat-treated and water quenched Cu-16 at.% Al-(6-10 at.%)Mn alloy, its transition temperatures, hardness and damping properties are presented and discussed. Martensitic structure was obtained in heat-treated and quenched alloy that shows relatively low transition temperature and small hysteresis.

U radu je dat pregled aktuelnog stanja u razvoju visokog obrazovanja metalurske struke u regionu, kao i prikaz međusobne usklađenosti na primeru Tehnickog fakulteta u Boru Univerziteta u Beogradu, Tehnolosko-metalurskog fakulteta u Beogradu Univerziteta u Beogradu, Fakulteta za naravoslovije in tehnologiju Univerze v Ljubljani (Slovenija), Metalurskog fakulteta u Sisku Sveucilista u Zagrebu (Hrvatska), Fakulteta za metalurgiju i materijale Univerziteta u Zenici (BiH), Metalurskotehnoloskog fakulteta u Podgorici Univerziteta Crne Gore (Crna Gora), kao i Tehnolosko-metalurskog fakulteta Univerziteta “Sv.Kiril i Metodije“ vo Skopje (Makedonija).

In this work the corrosion behaviour of Ni-Ti (Nitinol) shape memory alloy was studied using different electrochemical techniques including open circuit potential (EOC), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Samples made from nitinol alloy with diameter of 4 mm were used for microstructural and corrosion investigations. Testing solution was 0.9 % NaCl solution at pH=7.4, and temperature 37 °C. Microstructural analysis was performed by the optical and electron scanning microscopy (SEM) equipped with energy dispersive spectrometry (EDS). High values of the oxide film resistance (Rox) and the low value of corrosion current density (icorr) indicated high corrosion resistance of Ni-Ti alloy, but relatively low value of breakdown potential (Eb) indicates the possibility of development localised corrosion attack on the alloy surface. Size of pits was from 10 to 100 m and surface inclusions were initiation sites for the pitting corrosion.

In this work the corrosion behaviour of Ti-Ni (nitinol) shape memory alloy was studied using different electrochemical techniques including open circuit potential (EOC), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Samples made from nitinol alloy with diameter of 4 mm were used for microstructural and corrosion investigations. Testing solution was 0.9 % NaCl solution at pH=7.4, and temperature 37 °C. Microstructural analysis was performed by the optical and electron scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS). High values of the oxide film resistance (Rox) and the low value of corrosion current density (icorr) indicated high corrosion resistance of Ni-Ti alloy, but relatively low value of breakdown potential (Eb) indicates the possibility of development localised corrosion attack on the alloy surface. Size of pits was from 10 to 100 m and surface inclusions were initiation sites for the pitting corrosion.

In this work the corrosion behaviour of Ni-Ti (Nitinol) shape memory alloy was studied using different electrochemical techniques including open circuit potential (EOC), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Samples made from nitinol alloy with diameter of 4 mm were used for microstructural and corrosion investigations. Testing solution was 0.9 % NaCl solution at pH=7.4, and temperature 37 °C. Microstructural analysis was performed by the optical and electron scanning microscopy (SEM) equipped with energy dispersive spectrometry (EDS). High values of the oxide film resistance (Rox) and the low value of corrosion current density (icorr) indicated high corrosion resistance of Ni-Ti alloy, but relatively low value of breakdown potential (Eb) indicates the possibility of development localised corrosion attack on the alloy surface. Size of pits was from 10 to 100 m and surface inclusions were initiation sites for the pitting corrosion.

The results of thermodynamic study and characterization of some alloys in Ga-Sn-Zn system are presented in this work. Thermodynamic study was conducted experimentally - using Oelsen calorimetry method and analytically - according to Redlich-Kister-Muggianu model and compared with available literature data. Characterization of alloys was done using differential thermal analysis and scanning electron microscopy, and obtained results were used in phase diagram defining of investigated section in Ga-Sn-Zn system.