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The effect of tin content in the equilibrium phases of the Cu–Zn-based alloys, within the range of chemical compositions with interest to brass producers is described. For this purpose, ternary alloys with copper contents between 55.4 and 67.5wt.% and tin contents up to 5.30wt.% have been studied. The chemical composition of each alloy has been det...
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... composition, the microstructure of Table 2 Expressions, in the form of (%Sn) = A + B × (%Zn), determined by regression analysis indicating the chemical composition of the -phase in the two-phase field ( + ) at different homogenization temperatures the as-cast alloys produced in this work might consist only of the -phase in dendritic form ( Fig. 1(f)), the + phases ( Fig. 1(c) and (d)), equiaxial grains of -phase ( Fig. 1(a)) and + 1 or + 1 ( Fig. 1(e) and (b)), respectively. When the 1-phase is present in the microstructure of the as-cast al- loys, it is preferentially located at the grain boundary and/or at the interdendritic space ( Fig. 1(b) and ...
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... of Table 2 Expressions, in the form of (%Sn) = A + B × (%Zn), determined by regression analysis indicating the chemical composition of the -phase in the two-phase field ( + ) at different homogenization temperatures the as-cast alloys produced in this work might consist only of the -phase in dendritic form ( Fig. 1(f)), the + phases ( Fig. 1(c) and (d)), equiaxial grains of -phase ( Fig. 1(a)) and + 1 or + 1 ( Fig. 1(e) and (b)), respectively. When the 1-phase is present in the microstructure of the as-cast al- loys, it is preferentially located at the grain boundary and/or at the interdendritic space ( Fig. 1(b) and ...
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... (%Sn) = A + B × (%Zn), determined by regression analysis indicating the chemical composition of the -phase in the two-phase field ( + ) at different homogenization temperatures the as-cast alloys produced in this work might consist only of the -phase in dendritic form ( Fig. 1(f)), the + phases ( Fig. 1(c) and (d)), equiaxial grains of -phase ( Fig. 1(a)) and + 1 or + 1 ( Fig. 1(e) and (b)), respectively. When the 1-phase is present in the microstructure of the as-cast al- loys, it is preferentially located at the grain boundary and/or at the interdendritic space ( Fig. 1(b) and ...
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... by regression analysis indicating the chemical composition of the -phase in the two-phase field ( + ) at different homogenization temperatures the as-cast alloys produced in this work might consist only of the -phase in dendritic form ( Fig. 1(f)), the + phases ( Fig. 1(c) and (d)), equiaxial grains of -phase ( Fig. 1(a)) and + 1 or + 1 ( Fig. 1(e) and (b)), respectively. When the 1-phase is present in the microstructure of the as-cast al- loys, it is preferentially located at the grain boundary and/or at the interdendritic space ( Fig. 1(b) and ...
Context 5
... consist only of the -phase in dendritic form ( Fig. 1(f)), the + phases ( Fig. 1(c) and (d)), equiaxial grains of -phase ( Fig. 1(a)) and + 1 or + 1 ( Fig. 1(e) and (b)), respectively. When the 1-phase is present in the microstructure of the as-cast al- loys, it is preferentially located at the grain boundary and/or at the interdendritic space ( Fig. 1(b) and ...
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Analysis of metal objects with portable and handheld X-ray fluorescence spectrometry has become increasingly popular in recent years. Here, methodological concerns that apply to non-destructive, surface examination with XRF instruments of ancient metal artefacts are discussed based on the comparative analyses of a set of copper-based objects by mea...
Citations
... On the other hand, brass with appreciable quantities of tin was used for producing golden metallic pigments. Tin is one of the common alloying elements present in the composition of brasses: its presence improves mechanical properties of brasses in such a way that Cu-Zn-Sn alloys have an excellent cold workability (ASM Handbook 1992; Vilarinho et al. 2004). By SEM-EDS, such discoloured illuminations based on brass alloy pigments as gilding imitations have been identified in Armenian and Persian-Turkish illuminated manuscripts belonging to the sixteenth and eighteenth centuries, respectively, (Banik 1983). ...
Golden pigments are among the most common colourants used in Persian illuminated manuscripts. In this research, golden pigments were investigated in three eighteenth- to nineteenth-century manuscripts. Initially, scanning electron microscopy-energy dispersive spectrometry analyses showed that different kinds of metallic pigments were present and some of them were ternary alloys made up of copper, zinc and tin, hence copper-based alloys were ascertained as cheap alternatives to gold. Discolouration of the pigment was observable through alteration of the metallic pigments to greenish residues in the manuscripts. Subsequently, the greenish products in the golden pigments were studied by Raman spectroscopy. Copper carboxylates were recognized as degradation products. We inferred that the alteration is a consequence of the interaction between copper alloy pigments and carboxylic acids in conditions of high humidity. Moreover, more progressive degradation has caused the discolouration, brittleness and gradually crumbling of the paper in the painted areas. Signs of damages in the paper were comparable with decomposition of the paper by green copper pigments such as verdigris in historical documents and miniatures.
... Previous studies reported that Cu-Cr and Cu-Fe are age hardening alloys [1,2]. Tin (Sn) is a solid soluble element in brass, and also has an effect on its mechanical properties and the corrosion resistance [3]. However, there is no report about the microstructure and mechanical properties of brass alloyed with Cr, Fe and Sn. ...
The purpose of this research is the development of a high strength alpha-beta brass (Cu-40Zn) with additions of elements of small solid solubility in brass. Cu-40Zn with 0.6 wt.% Tin (Sn), 0.73 wt.% Chromium (Cr) and 0.51 wt.% Iron (Fe) were prepared by casting (Cu-40Zn-CrFeSn). The yield stress (YS) and ultimate tensile stress (UTS) of extruded Cu-40Zn-CrFeSn was 291 MPa and 601 MPa, 23 % and 36 % higher than that of extruded binary Cu-40Zn alloy. Vickers micro hardness of 158 Hv was higher than that of extruded Cu-40Zn alloy (131 Hv). In addition, the elongation of extruded Cu-40Zn-CrFeSn was 35 %. The strengthening mechanisms of these alloys were considered as follows; one was a solid solution strengthening of Cr, Fe and Sn additives which were identified by SEM-EDS. The other was increasing of the area ratio of beta-phase in Cu-40Zn-CrFeSn, compared to that of Cu-40Zn.
... In order to verify the correlation between the coins compositions (obtained by micro-EDXRF) and the major phases observed, an isothermal section of the Cu-Zn-Sn phase diagram at 450 ºC [14,15] was used (see Fig. 8). The microstructural effects of Pb, Fe and As were ignored because they do not seem to influence the α, β or γ phases formation directly. ...
... Due to similar microstructural effect and atomic mass proximity, a Sn equivalent content given by Sn+Sb will be used. Fig. 8. Coin distribution in partial isothermal section of Cu-Zn-Sn phase diagram at 450 ºC (adapted from [14]). Coin no. ...
Twenty brass Chinese cash coins with complex compositions were studied for a better understanding of the metallurgical cash production in China, during the 17(th), 18(th) and 19(th) centuries. Elemental composition was obtained through energy-dispersive micro X-ray fluorescence spectrometry of small cleaned areas on the coins rims. Results showed that these brass alloys (Cu-Zn) frequently contain up to 3% Sn, have highly variable Pb content (from n.d. up to 14%) and Fe, Sb, and As as minor elements. Microstructures were assessed by optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, and preliminary micro X-ray diffraction analysis. All the coins present typical as-cast microstructures although very fine-grained, which are supported by binary (Cu-Zn) and ternary (Cu-Zn-Sn) equilibrium phase diagrams, that explain microstructural differences due to the presence of Sn in these brasses.
... Particularly, brasses with improved mechanical and physical properties can be produced with the addition of a third element, for example Pb (leaded brasses) and Sn (tin brasses) [3]. Tin is one of the common elements present in the composition of brasses [4]. The tin bronzes are principal Cu-Sn alloys produced as casting alloys. ...
... In studies on the influence of tin in brass, the solubility of Sn in the Cu-Zn system that involves α-and β-phases was investigated as a function of zinc content [4]. Rapid dendritic growth in Cu-Sn alloys was studied in detailed [6]. ...
The direct smelting of scrap Copper to produce high-quality brass Alloy not only solves the problem of municipal solid waste, but also realizes the reuse of valuable metals and alleviates the problem of Copper shortage. However, Impurities are not easily controlled, and there are occasional Defects in the surface of secondary brass products such as door handles and mechanical parts. In this paper, Microstructure of the defective samples was studied with Scanning Electron Microscopy (SEM)), energy dispersive spectrometer (EDS), and electron probe microanalyzer (EPMA). The investigation findings suggest that Defects can be attributed to the Formation of γ phase brass, the Wrapped of refining agent or Slag, and the unremoved of impurity elements.
Typically, bismuth added in traditional Cu–Zn brass segregates as films or particles along the alpha-beta phase boundary and induces cracks after casting. The present work investigated the bismuth formation in lead-free Cu–Zn–Si yellow brass with various amounts of recycled bismuth–tin (Bi–Sn) solder. The results showed that no bismuth film segregated at the phase boundaries. In contrast, round particles of bismuth formed in the beta phase and at the alpha-beta phase boundaries when added 1 mass% Bi–Sn alloy and the bismuth particles embedded only in the alpha phase when added 2 to 4 mass% Bi–Sn alloy, respectively. The morphology of the fracture surfaces was significantly modified when Bi–Sn alloy content was increased. More importantly, there was no crack observed in as-cast samples and samples did not subject to any heat treatment process unlike the bismuth formation in other work. Thus, this work suggests that the addition of recycled Bi–Sn solder in lead-free Cu–Zn–Si yellow brass is beneficial to avoid cracks in castings and offer an original lead-free brass alloy with superior properties.
The purpose of this research is the development of a high strength α-β brass (Cu-40 Zn) with additions of elements of small solid solubility in brass. Cu-40 Zn with 0.6mass% Tin (Sn) and various contents of Chromium (Cr) and Iron (Fe) were prepared by casting (Cu-40 Zn-CrFeSn). The yield strength (YS) and ultimate tensile strength (UTS) of cast Cu-40 Zn-CrFeSn has 190MPa and 400MPa. Furthermore, the YS and UTS of extruded Cu-40 Zn-CrFeSn was 300MPa and 600MPa, 23% and 36% higher than that of extruded binary Cu-40 Zn alloy. Vickers micro hardness of 158Hv was higher than that of extruded Cu-40 Zn alloy (131Hv). In addition, the elongation of extruded Cu-40 Zn-CrFeSn was 35%. The strengthening mechanisms of these alloys were considered as follows; one was a solid solution strengthening of Cr, Fe and Sn additives which were identified by TEM-EDS and SEM-EDS. The other was increasing of the area ratio of β-phase in Cu-40 Zn-CrFeSn, compared to that of Cu-40 Zn.
The simultaneous electrochemical determination of lead (Pb) and cadmium (Cd) in low-cost jewelry was achieved using differential pulse voltammetry (DPV). The presented voltammetric detection via standard addition shows possible simultaneous analyses of Cd and Pb. The detection limit of 1.13 × 10⁻⁴% m m⁻¹ for lead and 1 × 10⁻³% m m⁻¹ for cadmium were obtained. The recovery rate ranged between 99 and 110% for Cd and 99-105% for Pb. Nine different low-cost jewelry pieces were analysed. Some were purchased from local trade while others were confiscated goods from the police force.
Significant research has been pursued to develop solar selective metallic coatings using a variety of coating deposition techniques, with limited attempts to assess the properties of bulk metallic materials for solar energy applications. In developing bulk solar reflectors with good reflectance in the entire solar range, we report a new class of reflector materials based on Cu–Sn intermetallics with tailored substitution of aluminium or zinc. Our experimental results suggest that the arc melted–suction cast Cu (78.8 at%)–Al (21.2 at%) alloy with nanoscale surface roughness can exhibit a combination of 89% bulk specular reflectance and 83% bulk solar reflectance, together with a hardness of 2 GPa. We show that the present alloy design approach paves the way for further opportunities of tuning the spectral properties of this new class of solar reflector material.
The precipitation hardening behavior of BS40-1.0Ti (Cu40Zn1.0Ti) was investigated with respect to mechanical properties and microstructures. Water atomized BS40 (Cu40Zn) and BS40-1.0Ti (Cu40Zn1.0Ti) alloy powders were used as raw powders. BS40-Ti premixed powder was prepared by mixing BS40 powder with 1.0 wt.% Ti powder elementally. Both BS40-Ti prealloyed and BS40-1.0Ti premixed powders were consolidated at 1073K for 0.6 ks by spark plasma sintering (SPS) and hot extruded subsequently. It was observed that the precipitation response of Ti between BS40 showed significant grain refinement effect on extruded BS40-1.0Ti alloys compared with BS40. Thus, excellent strengthening effect by precipitation hardening was obtained, which responding to yield strength of 345 MPa and 290 MPa, and ultimate tensile strength of 597 MPa and 520 MPa for extruded BS40-1.0Ti prealloyed and premixed alloys, which showed 65.9% and 39.5%, 30.4% and 13.6% higher values than that of the conventional extruded BS40 binary brass, respectively.
