Structure and Properties of Leaded Tin Bronze under Different Crystallization Conditions

Abstract

The influence of crystallization conditions of leaded tin bronze on the obtained microstructure parameters is examined in the paper. Modification of crystallization conditions was realised by varying the cooling rate of the melt with preheating of the casting molds. Quantitative regularities of the influence of the cooling rate of bronze on its phase composition are presented. Data on mechanical properties of the material under investigation are also reported in the paper. It is demonstrated that high cooling rates (casting into mold at ambient temperature) enable obtaining higher mechanical properties in comparison with low cooling rates (casting into mold heated up to 800 °С).

The Analysis of the Morphology of the Saddle-Shaped Bronze Chips Briquettes Produced in the Roller Press

“…Due to its low melting point, lead significantly facilitated the joining of particles under pressure. The addition of lead significantly improves the compactibility of copper powders during sintering [ 54 ]. In the case of its significantly higher content during the briquetting process, it creates bridges that connect loose particles ( Figure 12 d–g), facilitating the consolidation of chips.…”

Investigation of Effect of Casting Rate on Structure and Properties of Bronze Br010S2N3 Rods Prepared by Upwards Continuous Casting

“…Apparently this is connected with an increase in cooling rate with an increase in casting rate. It is well known that for tin-lead bronzes an increase in cooling rate leads to an increase in the proportion of intermetallic phases within the structure [3,[18][19][20][21]. As has been shown, intermetallic γ -Cu 3 Sn provides good wear resistance indices and it is expedient to provide as large a proportion of it as possible.…”

Structure and Properties of Multicomponent Bronze Depending on the Crystallization Conditions

“…Overheating affects the crystallization of the matrix grains only in the presence of suspended in fluid particles of poorly soluble admixtures. As a result of the melt overheating above the temperature of the deactivation, the particles of admixtures dissolve or lose their activity, that is, they lose the ability of nucleation for the liquid [5] surrounding them. At a low temperature of the casting tin particles are forced out by the growing dendrites, collide with each other and form multilink agglomerations not only in melt, but also in the process of crystallization.…”

“…The microstructure of bronze CuPb13Sn10Zn2Ni2 is represented in Figure 1, and it consists of matrix (α-solid solution of tin, zinc, and nickel in copper), eutectoid (Cu 31 Sn 8 + α-solid solution), and lead impurities. The metallographic analysis of the quantitative characteristic of the structure (eutectoid and lead) was carried out using optical microscope MIM-8М, digital photo-camera МDС-1500, and software "KOI System" [5,6], developed at the department of Materials Science and Materials Engineering. Sample hardness was determined according to Brinell hardness with loading 250 kg.…”