Effects of B on the Structure and Properties of Lead-Tin Bronze Alloy and the Mechanism of Strengthening and Toughening

High lead–tin bronze is widely used in the selection of wear-resistant parts such as bearings, bearing bushes, aerospace pump rotors, turbines, and guide plates because of its excellent wear resistance, thermal conductivity, fatigue resistance, and strong load-bearing capacity. At present, high lead–tin bronze is used as a material for bimetal cylinders, which cannot meet the requirements of high-strength, anti-wear in actual working conditions under high temperature, high speed, and heavy load conditions, and is prone to de-cylinder, cylinder holding, copper sticking, etc. The reason for the failure of cylinder body parts is that the strength of copper alloy materials is insufficient, the proportion of lead in the structure is serious, and the wear resistance of the material is reduced. Therefore, it has important theoretical significance and application value to carry out research on the comprehensive properties of high-performance lead–tin bronze materials and reveal the strengthening and toughening mechanism. In this paper, The ZCuPb20Sn5 alloy is taken as the main research object, and the particle size, microstructure, mechanical properties, and friction of lead particles in ZCuPb20Sn5 alloy are systematically studied after single addition of B in ZCuPb20Sn5 alloy liquid. This paper takes ZCuPb20Sn5 alloy as the research object to study the effect of adding B on the morphology, microstructure, mechanical properties, and friction and wear properties of ZCuPb20Sn5 alloy lead particles, and discusses the strengthening and toughening mechanism of ZCuPb20Sn5 alloy under the action of B, and prepares a double high-performance lead–tin bronze alloy for metal cylinders. The main research results are as follows: The addition of B elements has an obvious refining effect on the α (Cu) equiaxed grains and lead particles in ZCuPb20Sn5 alloy. The average size of lead particles decreases from 30.0 µm to 24.8 µm as the B content increases from 0 wt.% to 0.1 wt.%. The reason for grain refinement is that B is easily concentrated at the grain boundary during the ZCuPb20Sn5 alloy solidification process, which affects the diffusion of solute atoms at the solidification interface, inhibits the grain growth, refines the grain, and hinders the sinking and homogenizes distribution between dendrites of lead; the tensile strength of the ZCuPb20Sn5 alloy improves. Relatively without B, when the addition of P is 0.1 wt.%, the tensile strength is the largest at 244.04 MPa, which enhances 13%; the maximum hardness gets 75.0 HB, which enhances 13.6%, as well as elongation get the maximum value at 17.2%. The main mechanism is that the addition of B forms a high melting point submicron Ni4B3 phase in the lead–tin bronze alloy. The Ni4B3 phase is dispersed in the matrix and strengthens the matrix. With the increase in B content (more than 0.1 wt.%), the Ni4B3 phase changes from sub-micron degree granular to micron degree block-like, and some defects such as shrinkage and porosity appear in the structure, resulting in a decrease in mechanical properties.

Mineral inclusions in the late bronze age metal objects оf Southern Transurals

The paper is devoted to the determination of copper raw material types based on the analysis of mineral inclusions and the composition of metal objects from the Late Bronze Age settlements of the Southern Transurals (XIX–XIII centuries BC). The composition of alloys, inclusions of sulfdes, oxides and metals of objects was established by scanning electron microscopy. The composition of objects is dominated by copper and tin bronze, with a subordinate role of arsenic bronze. The presence of chalcocite and bornite inclusions in most objects indicates the use of rich ores from secondary sulfde enrichment zone. In comparison with analogs, the low total amount of sulfdes in the Southern Transuralian metal objects may indicate the use of mixed oxide and sulfde concentrates. The high Se and Te concentrations of sulfdes are indicative of using of ores of volcanic-hosted massive sulfde or skarn deposits. Keywords: metal objects, copper, bronze, sulfdes, Late Bronze Age, Southern Transurals

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.

WIELAND B31

Wieland B31 (CuSn2Fe0.1P) is a copper-tin-iron-phosphorus alloy (tin bronze) with coherent precipitates. The lower tin content with small amounts of iron and phosphorus results in an electrical conductivity of at least 30% IACS. Precipitates of iron and phosphorus stabilize the structure, increase the strength, and improve the softening characteristics. Wieland B31 possesses the right combination of formability, conductivity, strength, and stress relaxation resistance to be used for automotive applications at relatively high ambient temperatures. In addition, its strength is similar to that of a 4% tin bronze. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming and heat treating. Filing Code: Cu-926. Producer or source: Wieland-Werke AG.

The Chemical Composition of the Medieval Mirrors from Golden Horde Time Settlements

Introduction. The paper discussed the results of the study concerning the chemical composition of 16 mirrors from the Golden Horde period originating from the settlements Selitrennoe, Vodyanskoe, Uvekskoe Khmelevskoe I, Shirokiy Buerak and stored in the State Historical Museum (Moscow) and Saratov Regional Museum of Local Lore (Saratov). Method. The visual inspection of the items was carried out using the traceology method, XRF and SEM/EDS were used as a method of determining the elemental composition. To compare the results, data on the chemical composition of mirrors originating from other medieval sites in Eastern Europe were used. Analysis and Results. All but one mirror, made with a stone casting mold, were cast using the impression method. Some of the mirrors show traces of post-casting processing. Several types of alloys have been identified. Most of the mirrors were made of tin-lead bronze (7 items) with an increased (more than 20 %) tin content, which correlates with the results obtained on samples from other settlements of the pre-Horde and Horde times. Other large groups are mirrors made from multicomponent (3 items) and tin bronze (4 items). One mirror each is made of tin brass and lead bronze with the addition of arsenic. Mirrors with arsenic in their composition are also known from other samples from a nomadic cemetery of the Golden Horde period and settlement monuments, which indicates a sufficiently active existence of a more archaic metal in the 14th century.

Extraordinary Burial of Trikolsky Burial Ground in the Lower Reaches of the Belaya River

The article introduces into scientific discourse the materials of the burial 15 of the Trikolsky burial ground studied in 1978 by V.A. Ivanov. This burial featured finds unique for the entire Pyany Bor culture – a glass bowl and a cassolette. The burial also contained beads made of single-color and multi-colored glass and glass with a metal inlay, pendants made of adult moose incisors, bronze plaques, openwork overlays, temple pendants, etc. The authors concluded that the unique items came to the Pyany Bor population as a result of contacts with Sarmatian nomads in the 1st century AD. In addition, the study presents data on the manufacturing material of certain items obtained using natural scientific methods. It was determined that the cassolette was made of a sedimentary rock – argillite. Metal items, except a leaf-shaped pendant made of precious metal, are made of tin bronze. A “gum” sample discovered next to a glass bowl contains matter of vegetable origin. Its components are betulinic and tricyclic acids contained in birch bark and conifer resin (oleoresin), respectively.