Modifications of the chemical composition and microstructure of flash smelting copper slags in the process of their reduction

Blister copper smelting in a flash smelting furnace results in generation of slag that contains high amounts of copper, iron and lead. Most commonly, this material is subjected to reduction with coke in an electrical furnace. In the present paper, results of investigations on reduction of slag with another reducer, i.e. anthracite dust, are discussed. Each experimental slag was analysed for its microstructure, chemical composition and phase composition. Based on the results, a decopperisation level of the study material was estimated. It was shown that anthracite dust might be considered as an alternative for currently used reducers

Mikrostruktura wygrzewanych pokryć cynkowych typu galfan na podłożu stalowym

The commercially available Galfan coating containing 5-7wt.% of Al deposited on the low carbon steel substrate by hot dipping has been examined with respect to the microstructure of the coating/substrate interface area. The application of several experimental techniques (SEM/EDS, XRD, TEM/AEM/EDS/ED) allowed demonstrating the two-phase structure of the alloy coating in non-treated, commercially available Galfan samples: Zn-rich pre-eutectoid phase grains are surrounded by lamellar eutectics of -Al and -Zn. The transition layer between the alloy coating and steel substrate with the considerably higher Al content (SEM/EDS, TEM/EDS) has been found in both non-treated and annealed samples (600oC/5 minutes). Only the monoclinic FeAl3Znx phase however was revealed in the annealed sample (TEM/electron diffraction) remaining uncertain the presence of the orthorhombic Fe2Al5Znx phase, reported by several authors

Properties of Sonochemically Prepared CuInxGa1-xS2 and CuInxGa1-xSe2

Nanoparticles of chalcopyrites copper indium gallium sul de (CuInxGa1xS2 or CIGS) and copper indium gallium selenide (CuInxGa1xSe2 or CIGSe) were fabricated sonochemically. They were characterized by Xray di raction, scanning electron microscopy, energy dispersive X-ray spectroscopy, high resolution transmission electron microscopy, selected area electron di raction, and di use re ectance spectroscopy. The electrical and photoelectrical properties of the fabricated nanomaterials were investigated

Mikrostruktura i odporność na pełzanie stopów magnezu Mg-Al-Ca-Sr

Microstructure and creep properties of cast Mg-Al-Ca-Sr alloys have been investigated. The microstructure was characterized using light microscopy, scanning and transmission electron microscopy. Phase identification was made by EBSD technique and by SAED analysis. The measurement of volume fraction of intermetallic phases was performed using quantitative metallography. Creep tests were performed at 180°C and at applied stress between 45 and 90 MPa. Microstructure of tested alloys composed of α-Mg grains and intermetallic compounds in the interdendritic regions. It was found that the addition of calcium and strontium improves creep resistance at 180°C.W artykule przedstawiono wyniki badań mikrostruktury i odporności na pełzanie odlewniczych stopów magnezu Mg-Al-Ca-Sr. Mikrostrukturę badano metodami mikroskopii świetlnej, skaningowej i elektronowej transmisyjnej. Identyfikacji faz dokonano metodami EBSD i dyfrakcji elektronów (TEM). Pomiar udziałów objętościowych faz dokonano za pomocą metalografii ilościowej. Badania odporności na pełzanie przeprowadzono w temperaturze 180°C przez 100 h. Mikrostruktura badanych stopów składa się z ziaren roztworu stałego α-Mg i faz międzymetalicznych w przestrzeniach międzydendrytycznych. Stwierdzono, że dodatek wapnia i strontu poprawia odporność na pełzanie w temperaturze 180°C

The Influence of Strontium on the Microstructure of Cast Magnesium Alloys Containing Aluminum and Calcium

The structure of Mg-9Al-2Ca-xSr alloys is composed of a-Mg grains and the Al2Ca and Al4 Sr phases in the interdendritic areas. These phases are formed as a result of eutectic reactions. Globular particles of the Al8Mn5 phase are observed within the interior of the grains. The addition of strontium to Mg-9Al-2Ca-0.4Mn alloys causes the formation of the Al4Sr phase and increase of its volume fraction with increasing strontium levels. Moreover, increase of the strontium amount causes a decrease of aluminum content in the a-Mg solid solution

The Influence of Aluminum on the Microstructure and Hardness of Mg-5Si-7Sn Alloy

Magnesium alloys due the low density and good mechanical properties are mainly used in the automotive and aerospace industry. In recent years, magnesium alloys are extensively developed for use in high temperatures (above 120°C). Among these alloys, magnesium alloys containing tin and silicon have large possibilities of application due to the formation of thermally stable intermetallic Mg2Sn and Mg2Si. In this paper the influence of aluminum and heat treatment on the on the microstructure and hardness of Mg-7Sn-5Si alloy is reported. It was found that the microstructure of Mg-7Sn-5Si alloy consist of α-Mg solid solution, Mg2Sn and Mg2Si compounds. Addition of 2 wt% of Al to Mg-7Sn-5Si alloy causes the formation of Al2Sn phase. Moreover, Al dissolves in the α-Mg solid solution. The solution heat-treatment of tested alloys at 500°C for 24 h causes the dissolve the Mg2Sn phase in the α-Mg matrix and spheroidization of Mg2Si compound. The Mg2Si primary crystals are stable at solution temperature. After ageing treatment the precipitation process of equilibrium Mg2Sn phase was found in both alloys. The addition of aluminum has a positive effect on the hardness of Mg-7Sn-5Si alloy. In case of Mg-5Si-7Sn-2Al alloy the highest hardness was obtained for sample aged for 148 h at 250°C (88 HV2), while in case of Al-free alloy the highest hardness is 70 HV for material aged for 148 h at 250°C

The Mg₂ Sn precipitation process in the Mg-7Sn alloys with the addition of silicon and aluminum

In this paper the influence of alloying elements (Si and Al) on the precipitation process of Mg₂Sn phase in Mg-Sn alloys is presented. X-ray diffraction analysis was used to determine the lattice parameters of α -Mg solid solution, the phases content and size of the Mg₂Sn precipitates. It was found that silicon causes the refinement of the precipitates of Mg₂Sn phase, however it does not result in a significant increase of hardness increment after ageing treatment at 250°C. The addition of aluminum has a positive effect on the hardness of Mg-7Sn-5Si alloy

Wpływ strontu na mikrostrukturę odlewniczych stopów magnezu z dodatkiem aluminium i wapnia

The structure of Mg-9Al-2Ca-xSr alloys is composed of a-Mg grains and the Al2Ca and Al4 Sr phases in the interdendritic areas. These phases are formed as a result of eutectic reactions. Globular particles of the Al8Mn5 phase are observed within the interior of the grains. The addition of strontium to Mg-9Al-2Ca-0.4Mn alloys causes the formation of the Al4Sr phase and increase of its volume fraction with increasing strontium levels. Moreover, increase of the strontium amount causes a decrease of aluminum content in the a-Mg solid solution.W artykule przedstawiono wyniki badań wpływu strontu na mikrostrukturę odlewniczych stopów magnezu zawierających aluminium i wapń. Jakościową analizę fazową przeprowadzono za pomocą rentgenowskiej analizy fazowej i metody EBSD. Do ilościowej analizy fazowej zastosowano metody analizy obrazu. Po odlewaniu mikrostruktura stopów zawierających 9% mas. aluminium, 2% mas. wapnia, 0,3% mas. strontu i 0,4% mas. manganu składa się z roztworu stałego α-Mg oraz wydzieleń faz międzymetalicznych Al2Ca, Al4Sr i Al8Mn5. Zwiększenie zawartości strontu do 2% mas. powoduje zwiększenie udziału objętościowego fazy Al4Sr i zmniejszenie stężenia aluminium w roztworze stałym α-Mg

Characterisation of Microstructure of We43 Magnesium Matrix Composites Reinforced with Carbon Fibres

In the paper the microstructures of WE43 matrix composites reinforced with carbon fibres have been characterised. The influence of reinforcement type and T6 heat treatment (a solution treatment at 525°C for 8 h, a hot water quench and a subsequent ageing treatment at 250°C for 16 h) on microstructure have been evaluated. The light microscope and scanning electron microscope investigations have been carried out. No significant differences in samples reinforced with non-coated textiles have been reported. The substantial changes in sample reinforced with nickel-coated textile have been observed. The segregation of alloying elements to the matrix-reinforcement layer has been identified. The T6 heat treatment caused the appearance of disperse precipitates of β phase, but the process cannot be considered as satisfactory (irregular distribution, low volume fraction, relatively large size)