Bronze Materials Research Articles

Recycling and Characterization of Metallic Chips Using Powder Metallurgy

In this study, a new metal matrix composite material was produced by sintering from cast iron and bronze shavings made by recycling melting method. In the production of metal matrix composite material, 90% CuSn10 as a matrix material and 10% GGG40 cast iron as a reinforcement material were used. The chips having the same dimensions were mixed in a homogeneous mixture and pre-formed under a pressure of 1146 MPa and then sintered at 875 °C. The mechanical properties and porosity of the produced materials are characterized and the mechanical properties are compared with the mechanical properties of the bronze material in bulk state. According to the results, the mechanical properties of the material produced by the sintering method are very close to that of the bronze material in the bulk state.

Electrochemical corrosion behavior of bronze materials in an acid‐containing simulated atmospheric environment

AbstractThe present work investigates the corrosion behavior of bronze materials under thin electrolyte layers (TELs) in a simulated atmospheric environment containing formic and acetic acid by electrochemical measurements as well as surface characterization. The results show that the corrosion of bronze under TEL is significantly faster than that in the bulk solution, and the corrosion rate of bronze is the highest when the thickness of TEL is about 100 μm. Formic acid is observed to be more corrosive than acetic acid. Copper formate and copper acetate hydrate appear in the corrosion products formed on the surface of bronze, suggesting that the organic acid participates in the corrosion process of bronze materials in the simulated atmospheric environment.

ADATABLE INDUSTRIAL 4.0 : AN IMPROVEMENT DETECTED OBSOLETE BUSHING CONDITION ON RUBBER CURING MACHINE INDUSTRY

Bushing is a part of rubber curing machine that have function as cushion pin joint , generally make from a bronze material. Pin joint have a function to connected with 1 paired linkage arm with rotated crank gear of each via pin joint to get closing force at rubber curing machine when mould closed. When bushing condition at pin joint on rubber curing machine was not good caused by friction. It will make closing force linkage arm left and right ( 1 paired ) on rubber curing machine unbalanced. So it will make closing force to force closed rubber mould undistributed evenly, so it caused mould rubber closed with gap. This condition will make defect rubber product open mould after cured finished. In this case is important to find new methode detection and monitored bushing condition. This research was done by measured vibration around pin joint at linkage arm by taking data of sound and acceleration on the real object research and used 2D software simulator to measured bushing condition good or not. Acceleration measurement was done by measured at axis Y and Z by used accelerometer sensor, and accelero sensor on cell phone via sains journal android application. And collected the data stress value on linkage arm by used nidle dial gauge millimeter scale. By simulation software are measured acceleration at axis X and Y with good bushing condition or vise versa.The actual data that was collected : acceleration, sound vibration and stress value and simulated data by software to be compare the amplitude and choose the biggest amplitude as new methode measurement of vibration to detect and monitor bushing condition.From the result data, detection of vibration around pin joint by acceleration value by used accelerometer sensor measured at axis Y and Z more prefer with the other measurement methode.

Observations of mechanical and manual forging on bronze as a gamelan material

Gamelan is a traditional musical instrument used by Hindu Balinese in religious and cultural activities. The process of making gamelan begins with the manufacture of copper alloy composition (Cu) and lead (Sn), melting, casting, forging and tone forming by grinding on the surface of the blades. The process of forging on the manufacture of bronze gamelan (CuSn) with an open casting method absolutely must be done because the casting results tend to cause the occurrence of porosity. Porosity that occurs in the bronze as a gamelan material will affect the sound produced. The research conducted is to compare the results of manual forging and mechanical means, where the observations are made on the percentage of deformation that occurs, the density, the hardness and the microstructure of the bronze material. The observations show that mechanical forging provides better mechanical properties, deformation rates, and product microstructure.

Fabrication and sliding wear behavior of some lead-free bearing materials

The conventional journal bearing material contains varying amounts of lead (Pb) in it. Pb provides the anti-wear and anti-friction properties. However, Pb has hazardous effects on health and the environment. By considering the environmental aspect in mind, Pb free bearing materials are proposed in this paper. A copper-aluminium-nickel (Cu–NiAl) and copper-phosphorous-aluminium (Cu–PAl) materials were developed using the stir casting method and tribological performance of the developed materials was evaluated using a pin on disc experiments. The experiments were performed in fully flooded, starved and unlubricated conditions at a pressure of 0.31 MPa and 4.39 m s−1 sliding speed. Optical micrograph, Energy dispersive spectroscopy (EDS) and Scanning electron spectroscopy (SEM) images were obtained to inspect the wear behavior of the developed materials. For the fully flooded lubricating condition, Cu–NiAl resulted with better wear and friction properties as compared to the conventional Pb bronze material. During the starved and unlubricated condition, Cu–PAl material exhibited better tribological properties as compared to Cu–NiAl and Cu–Pb material.

Certification of ERM‐EB400, the First Matrix Reference Material for Lead Isotope Amount Ratios, and ERM‐AE142, a Lead Solution Providing a Lead Isotopic Composition at the Edge of Natural Variation

Lead isotope amount ratios are commonly used in diverse fields such as archaeometry, geochemistry and forensic science. Currently, five reference materials with certified lead isotope amount ratios are available, namely NIST SRM 981, 982 and 983, GBW‐04442 and NMIJ 3681‐a. Only NIST SRM 981 and NMIJ 3681‐a have approximately natural isotopic compositions, and NIST SRM 981 is predominantly used for correcting mass discrimination/mass fractionation in the applied mass spectrometric procedures. Consequently, there is no other certified reference material available to be used for validation and/or quality control of the analytical procedures applied to lead isotope amount ratio measurements. To fill this gap, two new reference materials have been produced and certified for their lead isotope amount ratios. For both certified reference materials, complete uncertainty budgets have been calculated and SI traceability has been established. This provides the users with independent means for validating and verifying their analytical procedures and for conducting quality control measures. ERM‐EB400 is a bronze material with a nominal lead mass fraction of 45 mg kg−1 and certified lead isotope amount ratios of n(206Pb)/n(204Pb) = 18.072(17) mol mol−1, n(207Pb)/n(204Pb) = 15.578(18) mol mol−1 and n(208Pb)/n(204Pb) = 38.075(46) mol mol−1 with the associated expanded uncertainties (k = 2) given in brackets. ERM‐AE142 is a high‐purity solution of lead in 2% nitric acid with a nominal mass fraction of 100 mg kg−1 and certified Pb isotope amount ratios of n(206Pb)/n(204Pb) = 21.114(17) mol mol−1, n(207Pb)/n(204Pb) = 15.944(17) mol mol−1 and n(208Pb)/n(204Pb) = 39.850(44) mol mol−1 with the associated expanded uncertainties (k = 2) given in brackets. Both materials are specifically designed to fall within the natural lead isotopic variation and to assist users with the validation and verification of their analytical procedures. Note that while one of these reference materials requires the chemical separation of Pb from its matrix (ERM‐EB400), the other does not (ERM‐AE142). As additional information, δ208/206PbNIST SRM981 values are provided for both materials. For ERM‐AE142, a delta value of δ208/206PbNIST SRM981 = −28.21(30)‰ was obtained, and for ERM‐EB400, a delta value of δ208/206PbNIST SRM981= −129.47(38)‰ was obtained, with the associated expanded uncertainties (k = 2) given in brackets.

Structural, electrical and relaxor properties of Sc-In solid solution in tetragonal tungsten bronze ceramics

The electrical properties of a family of tetragonal tungsten bronze (TTB) materials, Ba6Sc1-xInxNb9O30 (x = 0.25, 0.5, 0.75), which display relaxor properties were characterised using high- and low-temperature dielectric spectroscopy. All powders were synthesised at 1250 °C (24 h) + 1350 °C (6.5 h), while the pellets were further sintered at 1350 °C (12 h). At high temperature, the electrical conductivity in all samples is dominated by a single response, attributed to the bulk response, while the subtle asymmetry of the imaginary impedance peak suggests a minor contribution of the grain boundary response. In general, the Sc-In solid solutions samples exhibit similar electrical behaviour to the Sc compound, x = 1 reported previously (Ceram. Int. 2016, 42, 11810–11821). At low temperature all compounds exhibit frequency dependent relaxor behaviour. With increasing the content of In, the dielectric peaks are more asymmetric and the curves flatten more at temperatures above the transition temperature. The dipole freezing temperature, TVF, determined by Vogel-Fulcher (VF) analysis does not simply increase linearly as a function of M3+ (Sc3+,In3+) cation size, the extrapolation of VF-like curves results in considerably different values when compared to those found previously, since the acquired dielectric data are very sensitive to preparative conditions.

Corrosion behavior of bronze under organic acid‐containing thin electrolyte layer

The corrosion process and mechanism of three kinds of bronze materials under organic acid‐containing thin electrolyte layer (TEL) are investigated by electrochemical impedance spectroscopy (EIS) and Tafel polarization curves. It can be seen from the results that the corrosion rate of three specimens under TELs is lower than that in bulk solution. For bare bronze, the corrosion rate increases with the thickness of TEL, while for Cu2O patina bronze and CuCl patina bronze, there exists a critical thickness under TELs where the patina bronze have the maximum corrosion rate. In addition, the results show that Cu2O patina could increase the corrosion resistance, while CuCl patina, as a harmful patina, can accelerate the corrosion process. The principal corrosion products identified on the surface of bare bronze and Cu2O patina bronze are CuO, Cu(OH)2, and Cu(COOH)2, while the principal corrosion products identified on the surface of CuCl patina bronze is Cu2Cl(OH)3.

Effect of Reinforcement on Density, Hardness and Wear Behavior of Aluminum Metal Matrix Composites: A Review

The driving force for the utilization of Aluminum metal matrix composites over ferrous and nonferrous alloys like brass and bronze materials is due to the economic, performance and environmental benefits. Low noise, low emissions from aerospace vehicles and low consumption of fuel are the benefits in the transportation sector. With constant research in this field, improved fabrication techniques have evolved and this has led to the use of these composite materials instead of most of the monolithic materials in the marine and structural applications. The present studies are based on literature review on the properties like density, hardness and behavior of aluminum metal matrix composites during wear. The density has found to increase with increase in reinforcement of particulate with higher density values. It is found that the wear resistance and hardness properties have been found to increase upon addition of reinforcement material. A consolidated review is made and conclusions are derived.

Experiments, analysis and parametric optimization of cylindrical traverse cut grinding of aluminium bronze

The usage of high-strength wear-resisting aluminum bronze alloys is increasing in various industrial applications. The surface roughness prediction for these materials is increasingly important. The present investigation focuses to investigate the significance of process parameters on surface roughness of cylindrical traverse cut grinding of aluminum bronze material. The roughness data is analyzed with the help of analysis of signal to noise ratio and graphical presentations like main effect and interaction plots. Optimum parametric setting has been obtained by Taguchi method. Further confirmation test of the optimized combination was done to confirm the results obtained from Taguchi method. The results of the present study may provide the knowledge / data base of cylindrical grinding process for prediction of surface finish of aluminum bronze material at given setting of process parameters.

Новые материалы на памятнике позднего бронзового века Ложка-6 в Барабинской лесостепи

Новые материалы на памятнике позднего бронзового века Ложка-6 в Барабинской лесостепи

Experimental Investigation of the Flame Propagation and Flashback Behavior of a Green Propellant Consisting of N2O and C2H4

Regarding the research on alternatives for monopropellant hydrazine, several so called green propellants are currently under investigation or qualification. Aside others, the DLR Institute of Space Propulsion investigates a N2O/C2H4 premixed green propellant. During the research activities, flashback from the rocket combustion chamber into the feeding system has been identified as a major challenge when using the propellant mixture. This paper shows the results of ignition experiments conducted in a cylindrical, optical accessible ignition chamber. During the ignition and flame propagation process, pressure, temperature and high-speed video data were collected. The high speed video data were used to analyze the flame propagation speed. The obtained propagation speed was about 20 m/s at ignition, while during further propagation of the flame speeds of up to 120 m/s were measured. Additionally, two different porous materials as flame arresting elements were tested: Porous stainless steel and porous bronze material. For both materials Peclet numbers for flashback were derived. The critical Peclet number for the sintered bronze material was around 20, while for the sintered stainless steel the critical Peclet number seems to be larger than 40. Due to the test results, sintered porous materials seem to be suitable as flashback arresters.

Art Museums: a Good Context for Outreach Activities on Natural Stones and Heritage

Natural stones have had an important use in sculpture, both as the main material and as suitable bases on which to mount and enhance the artistic pieces. Many pieces of art can be admired in museums around the world standing on beautiful stones. However, in very few cases are the stones given correct recognition or names. In general, they are all labelled as “marble”. Illustrative examples can be provided from museums in Salamanca, Spain: Museum Casa Lis but, also, and, briefly, the museum Mateo Hernandez. The first of these is a very prestigious museum where a superb collection of Art Nouveau and Art Deco sculptures can be admired. Among them are many chryselephantine: sculptures made of ivory, bronze and other materials dating from the European nineteenth century art, placed on plinths of natural stone. Our work has identified, as accurately as possible, those stones. Most of the natural stones used as pedestals consist of onyx, but there are many other stones, ranging from serpentinite to travertine as well as some, as yet, unidentified materials. The second museum, Mateo Hernandez, houses a large collection of sculptures by this local artist. The sculptor used different kind of stones, but mainly “Petit Granit”, from Belgium. Despite the trade name, it is actually a type of limestone, but most museum catalogues have translated the name as “Black Granite”. The aim of our work is to help curators to correctly describe stones. The character of the natural stone is related to the aesthetic qualities and history of the sculpture. But proper identification of the stone can also contribute to important work for earth scientists: to disseminate understanding of the importance of natural stones, historical quarries and geoheritage among the general public.

Anthropology and Historiography: A Deconstructive Analysis of K. C. Chang’s Shamanic Approach in Chinese Archaeology

Abstract The hypothesis of ancient Chinese shamanism popularized by K. C. Chang in the 1980s has long been one of the central problems in the study of Chinese archaeology. By examining the structures that constitute Chang’s shamanic framework, this article argues that the problem centers around two major issues. The first is that Chang follows a tradition in Chinese academic historiography of using late historical texts to interpret Neolithic and Bronze Age materials. The second is that, in order to explore the dynamics of the formation of Chinese civilization, he employs Western theories in his construction of the history of shamanism. This article discusses the problems associated with using textual materials for interpretations of archaeological finds. It also discusses “substratum theory,” the way in which it influenced Chang’s understanding of shamanic civilization, and the manner in which Western anthropological theory was incorporated into Chang’s historiographical model. Accordingly, the author concludes that this shamanism problem in Chinese archaeology actually stems from a mixture of the Chinese historiographical tradition and Western anthropological theories, which together make Chang’s writing develop a meta-narrative that leads directly to two characteristics: generalization and polymorphism.

Finding Hama: On the Identification of a Forgotten Queen Buried in the Nimrud Tombs

Finding Hama: On the Identification of a Forgotten Queen Buried in the Nimrud Tombs

Determination of the Tin Stable Isotopic Composition in Tin‐bearing Metals and Minerals by MC‐ICP‐MS

This study uses MC‐ICP‐MS for the precise analysis of the stable tin isotopic composition in ore minerals of tin (cassiterite, stannite), tin metal and tin bronze. The ultimate goal is to determine the provenance of tin in ancient metal objects. We document the isotope compositions of reference materials and compare the precision of different isotope ratios and the accuracy of different procedures of mass fractionation correction. These data represent a base with which isotopic data of future studies can be directly compared. The isotopic composition of cassiterite and stannite can be determined after reduction to tin metal and bronze, respectively. Both metals readily dissolve in HCl, but while the solutions of tin metal can be directly measured, the bronze solutions must be purified with an anion exchanger. The correction of the mass bias is best performed with an internal Sb standard and an empirical regression method. A series of Sn isotope determinations on commercially available mono‐element Sn solutions as well as reference bronze materials and tin minerals show fractionations ranging from about −0.09‰ to 0.05‰/amu. The combined analytical uncertainty (2s) was determined by replicate dissolutions of reference materials of bronze (BAM 211, IARM‐91D) and averages at about 0.005‰/amu.

Propeller material belt grinding parameters optimisation using Taguchi technique

Belt grinding has been employed to achieve the finished geometry and the surface quality of large marine propeller with manganese bronze material (ZCuAl8Mn13Fe3Ni2). However, it is very challenging to select a group of reasonable belt grinding parameters with the consideration of accuracy, efficiency and economy simultaneously, which is always dealt by trial-and-error actually. This research mainly focuses on belt grinding parameters optimisation utilising Taguchi technique for improving surface roughness, belt wear and material remove rate. Four main factors were taken into account, including abrasive grain size, grinding speed, feed rate and grinding depth. The influences of those factors on grinding process were analysed through S/N ratios and analysis of variance (ANOVA). A number of experiments were conducted on a five-axis computer numerical control (CNC) belt grinding machine according to the parameters orthogonal array (OA). It showed that surface roughness, belt wear and material remove rate have been improved using the optimised belt grinding parameters.

Warm Spraying of High-Strength Ni-Al-Bronze: Cavitation Characteristics and Property Prediction

Bronze materials such as Ni-Al-bronze show exceptional performances against cavitation erosion, due to their high fatigue strength and high strength. These materials are used for ship propellers, pump systems or for applications with alternating stresses. Usually, the respective parts are cast. With the aim to use resources more efficiently and to reduce costs, this study aimed to evaluate opportunities to apply bronze as a coating to critical areas of respective parts. The coatings should have least amounts of pores and non-bonded areas and any contaminations that might act as crack nuclei and contribute to material damages. Processes with low oxidation and high kinetic impacts fulfill these criteria. Especially warm spraying, a nitrogen-cooled HVOF process, with similar impact velocities as cold gas spraying but enhanced process temperature, allows for depositing high-strength Ni-Al-bronze. This study systematically simulates and evaluates the formation and performance of warm-sprayed Ni-Al-bronze coatings for different combustion pressures and nitrogen flow rates. Substrate preheating was used to improve coating adhesion for lower spray parameter sets. Furthermore, this study introduces an energy-based concept to compare spray parameter sets and to predict coating properties. Coatings with low porosities and high mechanical strengths are obtained, allowing for a cavitation resistance similar to bulk material.

Zinc Vapor Trapping Using Copper-Based Materials

As part of the development of a long range solution for zinc vapor capture, a series of experiments utilizing commercially available copper and bronze screen and bronze sheet materials were conducted. The testing used a high-vacuum system in which zinc was vaporized and condensed on the zinc getter material at various temperatures. A fixed zinc vaporization temperature was used and the zinc getter material, and consequently the condensation temperature, was varied. The testing revealed that zinc vapor was captured over a wider range of temperatures on bronze materials than on the copper screens.

Non-matrix-matched determination of lead isotope ratios in ancient bronze artifacts by femtosecond laser ablation multi-collector inductively coupled plasma mass spectrometry

In this study, lead isotopic ratios in bronze artifacts were non-matrix-matched determined directly by femtosecond laser ablation multi-collector inductively coupled plasma mass spectrometry (fsLA-MC-ICP-MS). We evaluated the necessity of matrix matching for lead isotope ratio analyses of bronzes by adopting thallium solution to correct mass discrimination during mass spectrometer measurements. Lead isotope ratios of four bronze reference materials were measured by fsLA-MC-ICP-MS to determine the quality of data when calibrating samples with standards having different physical characteristics and chemical compositions. The average 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb, 207Pb/206Pb and 208Pb/206Pb ratios determined by fsLA-MC-ICP-MS were within 0.06% of that by solution nebulizer MC-ICP-MS (SN-MC-ICP-MS). The results indicate that accurate lead isotopic compositions could be obtained by fsLA-MC-ICP-MS technique after non-matrix-matched standards calibration. Additionally, the lead isotopic compositions are presented for five Chinese bronze reference materials using fsLA-MC-ICP-MS. Homogeneity of lead isotope distribution was expressed as the RSD range from 0.010% to 0.017% for 208Pb/204Pb, 207Pb/204Pb, 206Pb/204Pb ratios. Therefore, the five bronze materials could potentially serve as external calibration standards and quality control samples for in situ lead isotope measurements of ancient bronze artifacts. The fsLA-MC-ICP-MS technique could be applied to differentiate the high radiogenic lead in bronze artifacts from common lead.