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This study characterizes the bronze jewellery recovered from the Lusatian culture urn-field in Mała Kępa (Chełmno land, Poland). Among many common ornaments (e.g. necklaces, rings, pins) the ones giving evidence of a steppe-styled inspiration (nail earrings) were also identified. With the dendritic microstructures revealed, the nail earrings prove the implementing of a lost-wax casting method, whereas some of the castings were further subjected to metalworking. The elemental composition indicates the application of two main types of bronze alloys: Cu-Sn and Cu-Sn-Pb. It has been established that the Lusatian metalworkers were familiar with re-melting the scrap bronze and made themselves capable of roasting the sulphide-rich ores.

This preliminary study characterizes the bronze metalworking on a defensive settlement of the Lusatian culture in former Kamieniec (Chełmno land, Poland) as it is reflected through casting workshop recovered during recent excavations. Among ready products, the ones giving evidence of local metallurgy (e.g. casting moulds and main runners) were also identified. With the shrinkage cavities and dendritic microstructures revealed, the artifacts prove the implementing a casting method by the Lusatian culture metalworkers. The elemental composition indicates application of two main types of bronzes: Cu-Sn and Cu-Pb. Aside these main alloying additions, some natural impurities such as silver, arsenic, antimony and nickel were found which may be attributed to the origin of the ore and casting technology.

Interdiffusion between Fe (Armco) and Cu single crystals of similar orientation (around [110]) annealed at temperatures of 873 and 973K in air for 0.5 up to 4 h is studied. Formation of three phases different in their chemical composition has been observed: 1) oxide layer on Cu border (porous), 2) a layer rich in copper, iron and oxygen, 3) a layer of iron and oxygen with only small addition of Cu. All reactions of interface formation occurred in solid state. It was noted that oxygen plays an important role in development of new phases. Strong Kirkendall effect is observed due to large difference in diffusion coefficients of copper atoms to iron, DCu→Fe=300exp(-67800/RT) and iron atoms to copper DCu→Fe=0.091exp(-46140/RT).

The analysis of the connection steel/Al/steel made by resistance welding was performed. The used low-carbon steel had low content of carbon and other elements, aluminum was of 99.997 wt.% Al purity. Formation of various FeAl intermetallic phases found in the phase diagram depending on the duration of the process was analyzed. Two distinctively different types of structure depending on time of welding were observed: 1) hypoeutectic structure for samples processed for 5 s, and 2) eutectic structure for samples processed for 10 s and more. The shear test showed increase of mechanical properties of the connection for the samples welded 10 s.

Currently there is a constant development in the field of aluminium alloys engineering. This results from, i.a., better understanding of the mechanisms that direct strengthening of these alloys and the role of microalloying. Now it is microalloying in aluminum alloys that is receiving a lot of attention. It affects substantially the macro- and microstructure and kinetics of phase transformation influencing the properties during production and its exploitation. 7xxx series aluminum alloys, based on the Al-Zn-Mg-Cu system, are high-strength alloys, moreover, the presence of Zr and Sr further increases their strength and improves resistance to cracking.

Processes of severe plastic deformation (SPD) are defined as a group of metalworking techniques in which a very large plastic strain is imposed on a bulk material in order to make an ultra-fine grained metal. The present study attempts to apply Equal-Channel Angular Pressing (ECAP), Hydrostatic Extrusion (HE) and combination of ECAP and HE to 99.5% pure aluminium. ECAP process was realized at room temperature for 16 passes through route Bc using a die having an angle of 90°. Hydrostatic extrusion process was performed with cumulative strain of 2.68 to attain finally wire diameter of d = 3 mm. The microstructure of the samples was investigated by means of transmission and scanning electron microscopy. Additionally, the microhardness was measured and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns misorientation was determined. The measured grain/subgrain size show, that regardless the mode of deformation process (ECAP, HE or combination of ECAP and HE processes), grain size is maintained at a similar level – equal to d = 0.55-0.59 μm. A combination of ECAP and HE has achieved better properties than either single process and show to be a promising procedure for manufacturing bulk UFG aluminium.

Purpose: Modification of sintered iron with the addition of molybdenum and boron leads to the formation of boride phases that significantly impact the properties of the sintered materials. The paper aims to determine Fe-Mo-B phases that might be formed during the sintering of base powders. With EDS microanalysis, determining those phases in the microstructure is difficult since the B-Kα peak is extremely close to Mo-Mζ (only a 9.3 eV difference). Thus, diffraction techniques must be implemented to unambiguously define the phases occurring in the sintered samples (WDS and EBSD). Design/methodology/approach: The sintered samples were obtained from initial powders of Fe, Mo, and B that were mixed and compressed. The reducing hydrogen atmosphere was used to sinter green samples at 1200°C for 60 minutes. The obtained sinters were subjected to microstructural observations by scanning electron microscope, and some analyses (EDS/WDS and EBSD) were conducted, which led to the determination of phases present in the material. Findings: Based on the investigations conducted, iron, molybdenum, and molybdenumiron borides have been reported. It is confirmed with the EBSD method that Fe2B, MoB and FeMo2B2 phases are formed in particles' connection regions. Besides, the interparticle region, formed due to a liquid phase during sintering, is based on Fe-Fe2B eutectic. The microstructural observations prove that the amount of the liquid phase, and thus the size of the interparticle region, diminishes with increasing molybdenum content. It was also noted that the iron matrix (interior of former iron particles) is free from contributing elements coming from boron or molybdenum powders. Research limitations/implications: The application of the EDS method is limited in the case of measuring boron in Mo-containing alloys and phases. The EDS method does not have a sufficient energetic resolution to separate the B-Kα line from Mo-Mζ one. Thus, it must be complemented with WDS and EBSD in order to unambiguously determine the presence and localization of iron and molybdenum borides. Practical implications: It can be stated that WDS has sufficient energy resolution to separate B-Kα from Mo-Mζ emission lines. Therefore, WDS analysis is suitable for boride observation in sintered iron powders by constructing distribution maps of interparticle connection regions and precipitates. Besides, measurements by the EBSD method can be used to confirm the presence of Fe2B, MoB and FeMo2B2 phases. Originality/value: Determination of boron-containing phases in Fe-Mo-B sinters by means of diffraction methods. [ABSTRACT FROM AUTHOR]

The studied silicon bronze (CuSi3Zn3Mn1) is characterised by good strength and corrosion resistance due to the alloying elements that are present in it (Si, Zn, Mn, Fe). This study analysed the casting process in green sand moulding, gravity die casting, and centrifugal casting with a horizontal axis of rotation. The influences of Ni and Zr alloying additives as well as the casting technology that was used were evaluated on the alloy’s microstructure and mechanical properties. The results of the conducted research are presented in the form of the influence of the technology (GS, GZ, GM) and the content of the introduced alloy additives on the mechanical parameters (UTS, A10, and Proof Stress, BHN). The analysis of the tests that were carried out made it possible to determine which of the studied casting technologies had the best mechanical properties. Microstructure of metal poured into metal mould was finer than that which was cast into moulding compound. Mechanical properties of castings made in moulding compound were lower than those that were cast into metal moulds. Increased nickel content affected the BHN parameter. [ABSTRACT FROM AUTHOR]

One of the most interesting categories of artifacts for archaeometallurgical research includes deposits of bronze items, so-called "metallurgists hoards". They contain, aside of final products, many fragments of raw material and, moreover, metallurgical tools. An important source for the studies on the history of metallurgical technology is hoard from Przybysław, Greater Poland district. Thus, the aim of the work is the identification and interpretation of bronze-working practices and strategies adopted by prehistoric communities of the Late Bronze Age and the Early Iron Age (ca. 600 BC). The examined objects are characterized in terms of their design, structure, and chemical composition. The methods chosen for the studies of artifacts include: metallographic macro- and microscopic observations using optical microscopy (OM) and scanning electron microscopy (SEM), the analysis of chemical composition with the methods of energy dispersive X-ray spectroscopy (EDS), and X-ray fluorescence (ED-XRF). The thermodynamic analysis of the alloys was performed on the basis of the CALPHAD method. The experimental melts allowed to verify the theoretical considerations and to determine the characteristic temperatures of changes. The old casting technology can be analyzed basing on computer modeling and computer simulation methods. Simulations in the MAGMASOFT® software are a good example to illustrate how to fill a mould cavity with a molten bronze for a hoop ornament. It is also an appropriate tool to determine temperature distribution in a mould. The simulations also show the possible disadvantages with this old technology. [ABSTRACT FROM AUTHOR]

Silicon bronzes are characterised by good mechanical properties and by high corrosion and mechanical wear resistance. The process of sleeve casting by means of the centrifugal casting with the horizontal axis of the mould rotation was analysed. The assessment of the influence of modification and centrifugal casting parameters on the microstructure and mechanical properties of alloys was carried out in the hereby work. Zirconium was applied as a modifier. Speed of rotation of the mould was the variable parameter of the centrifugal casting. The investigation results were summarised on the basis of the microstructure analysis and mechanical properties determination: UTS, proof stress, A10 and BHN. The experiment aimed at finding the information in which way the modification together with changing the pouring parameters influence the mechanical properties of the CuSi3Zn3FeMn alloy. [ABSTRACT FROM AUTHOR]

High prices of tin and its limited resources, as well as several valuable properties characterising Cu-Sn alloys, cause searching for materials of similar or better properties at lower production costs. The influence of various nickel additions to CuSn10 casting bronze and to CuSn8 bronze of a decreased tin content was tested. Investigations comprised melting processes and casting of tin bronzes containing various nickel additions (up to 5%). The applied variable conditions of solidification and cooling of castings (metal and ceramic moulds) allowed to assess these alloys sensitivity in forming macro and microstructures. In order to determine the direction of changes in the analysed Cu-Sn-Ni alloys, the metallographic and strength tests were performed. In addition, the solidification character was analysed on the basis of the thermal analysis tests. The obtained results indicated the influence of nickel in the solidification and cooling ways of the analysed alloys (significantly increased temperatures of the solidification beginning along with increased nickel fractions in Cu-Sn alloys) as well as in the microstructure pattern (clearly visible grain size changes). The hardness and tensile strength values were also changed. It was found, that decreasing of the tin content in the analysed bronzes to which approximately 3% of nickel was added, was possible, while maintaining the same ultimate tensile strength (UTS) and hardness (HB) and improved plasticity (A5). [ABSTRACT FROM AUTHOR]

The conducted studies regarded the analysis of change of structure of point defects occurring during initial stage of recovery of FCC (Al, Cu) and HCP (Ti, Mg and Zn) metals at temperature close to Th =0.5Tm. The changes in resistivity of the deformed and later recovered samples were measured. The recovery time was 1, 2, 3, 4 or 5 min. The observed changes were correlated with reorganization of arrangement of lattice defects during annealing. [ABSTRACT FROM AUTHOR]