Effect of Homogenization Annealing on Wear Properties of Thixo-Extrued Copper Alloy

The semi-solid extruded CuSn10P1 alloy bushings were homogenization annealed. The effects of annealing process on the hardness and wear properties of bushings were researched. The results show the Brinell hardness increases firstly and then decreases with the increase of annealing temperature and annealing time. With the annealing temperature increasing, the grinding loss rate and friction factor decrease firstly and then increase. At the annealing time of 120 min, the grinding loss rate decreases from 7% at the annealing temperature of 450 °C to 6% at 500 °C, and then increases from 6% at 500 °C to 12% at 600 °C. The friction factor decreases from 0.54 to 0.48 and then increases to 0.83. At the annealing temperature of 500 °C, the grinding loss rate decreases from 11% at the annealing time of 60 min to 6% at 120 min, and then increases to 15% at 150 min. The friction factor decreases from 0.67 to 0.48 and then increases to 0.72. The best wear performance and Brinell hardness can be obtained at annealing temperature of 500 °C for 120 min.

Non-Destructive In Situ Investigation of the Study of a Medieval Copper Alloy Door in Canosa di Puglia (Southern Italy)

This paper reports the analyses carried out on the medieval copper alloy door (1111–1118 AD) of the mausoleum of Boemondo d’Altavilla in Canosa di Puglia (Southern Italy). The studied door is the smallest medieval bronze door extant in Italy and, unlike the other Byzantine doors, was most probably made in Canosa di Puglia and not in Constantinople. Analyses were performed to assess the chemical composition of the alloy patinas using a portable energy dispersive X-ray fluorescence (ED-XRF) instrument designed at the University of Salento. The experimental results suggested that the two door leaves have the same chemical composition, even if they appear different in both style and size. Furthermore, the alloy used for the door is different from the other previously-analyzed Byzantine bronze doors. The obtained results can be used in the future to compare the chemical composition of other Byzantine doors in order to better understand the manufacture of these precious artifacts.

Highly efficient catalytic oxidation of 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid with bimetallic Pt-Cu alloy nanoparticles catalyst

Bimetallic platinum-copper alloy nanoparticles is a highly active catalyst for the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) under base-free conditions, with a high turnover frequency up to 135...

Investigation of Wear Properties of Microtitanium and CNT Particulates Reinforced Copper Hybrid Metal Matrix Composite

Current engineering applications require materials that are stronger, lighter, and less expensive. Substituting composite structures for conventional metallic structures has many advantages because of higher specific stiffness and strength of composite materials. In the recent days, there is a huge demand for a lightweight material such as composites seems to be a promising solution to this arising demand. These materials have gained attention due to their applications in the field of automotive, aerospace, sports goods, medicines, and household appliances. This study represents the work done by various researchers and their methodologies. In contrast with most metallic materials, copper alloy has many remarkable properties, such as its excellent electrical and thermal conductivities, good strength, and formability, having outstanding resistance to corrosion and fatigue, and others. Due to their excellent properties, copper alloy is widely used in electrical, automotive, architecture, petrochemicals, transportation, and marine industry. In this work the different percentages of CNT and MicroTitanium are reinforced with pure Copper and are studied. The current work investigated the influence of the CNT and MicroTitanium on the wear behavior (tribological behavior) of developed hybrid metal matrix composite. The conventional liquid stir casting technique will be used for the fabrication of the composite materials. The composite was produced considering combination of0.5, 1, 1.5 percentages of CNT and 1, 3, 5 percentages of Micro-Titanium. The specimens were prepared as per ASTM standard size by turning and facing operations to conduct wear test. The specimens for investigation of wear were tested using pin on disk apparatus. Through the results, it is concluded that the hybrid MMC obtained has got better reduction in wear rate. The inclusion of CNT has played a major role in reducing the wear rate and addition of micro titanium has decreased the wear rate to some extent Keywords: Wear, Copper, Micro titanium, CNT, MMC

Electrochemical deposition of tin-copper alloy coatings

Solderable tin-base alloy coatings are widely used when assembling electronic products. The reorientation of production to lead-free technologies sets the task of developing new technological processes for the formation of coatings for electrical contacts with stable electrical properties, high soldering ability, which lasts for a long time. The features of the process of electrodeposition of coatings with a tin-copper alloy were experimentally investigated and the regularities of the influence of the electrolyte composition, current density, and ultrasound intensity on the cathode current efficiency of the alloy, the deposition rate, elemental composition, structure and functional properties of the precipitation were established. For sonochemical treatment an experimental setup developed at Research Laboratory 5.2 of BSUIR, which makes it possible to vary the intensity of ultrasonic vibrations in the range of 0.058– 1.7 W/cm2 , was used. It has been established that the use of ultrasound changes the formation mechanism of the electrochemical alloy, reduces cathodic polarization, increases the value of the limiting current and makes it possible to control the composition and structure of the precipitates. With an increase in the intensity from 0.12 to 0.95 W/cm2 the amount of copper in the coating increases by 4.5 times. The spreading coefficient of the solder is 92.59–98.44 %.

Hitherto Unknown Technology of Bronze Age Inlay

Daggers discovered at Tserovani cemetery of the Bronze Age - prominent specimens of decorative-applied art selected for the new exhibition of the Museum of Archaeology of the State Museum-Reserve of Greater Mtskheta – were submitted to the restoration-research laboratory of archaeological and ethnographic objects of S. Janashia Museum of Georgia of the Georgian National Museum because of repeated corrosion in some areas. Dagger N7232 is composed and its handle is abundantly incrusted with vitreous mass. Most of the incrustation is produced with the method of melting vitreous mass inside a metal cutting. A strange exception is white circular inlay against blue background situated in three triangular cuttings. One of incrustations is damaged. The remnants were found in the cut of damaged incrustation were the vitreous mass and small grey, tubular rods made of 94% tin and 4% copper alloy (pewter) fitted in a wooden remnant. Research allowed us to interpret presumable methods and prominence of producing incrustation: white glass embedded in circular silver partitions against the background of blue glass. The analyses showed that the dagger was made from the typical for the late bronze period alloy- tin bronze. The artefacts, with all signs of historical development (technology, decoration methods, and ornamental motives) belong to the Colchian culture and can date in frame of this culture. Based on the presently available data it can be stated that we are dealing with a completely new technology unknown up to present and that it can be regarded as predecessor of the cloisonne incrustation.