The Effect of Annealing Temperature Treatment and Pb Addition on the Impact Strength of High-Tin Bronze

Abstract

High tin bronze with an alloy composition of 80% Cu and 20% Sn is usually widely used in industries such as components that require high wear resistance and strength such as bearings and bearing bushings. In addition, this material is also known for its good acoustic properties, so it is often used in the manufacture of musical instruments such as bells and gamelan. The weakness of this alloy composition is its brittle nature which can be caused by porosity during the casting process. Efforts that can be made to reduce the brittle nature of high-tin bronze alloys are by adding black lead (Pb) and annealing treatment. In this study, the casting process of high tin bronze alloys was carried out with the addition of Pb with variations of 5%, 10%, and 15% and variations in annealing treatment at temperatures of 400 oC, 500oC, and 600oC with a closed time of 1 hour. The cast material was machined for impact test specimens. The impact test results showed that the higher the impact annealing value, the higher it increased. The highest impact value is found in the 80%Cu-20%Sn alloy without the addition of Pb at an annealing temperature of 600 oC of 0.036 Joule/mm2. While the lowest impact value is obtained in the High-tinbronze + 10% Pb alloy at an annealing temperature of 400 oC of 0.010 Joule/mm2.