Eventos Anais de eventos
COBEF 2019
COBEF 2019
THE INFLUENCE OF THERMAL VARIABLES OF SOLIDIFICATION ON THE MICROSTRUCTURE, HARDNESS AND MICROHARDNESS OF CU-8.5 WT% SN ALLOY
Submission Author:
Givanildo Santos , SP
Co-Authors:
Givanildo Santos, Ricardo Aparecido da Cruz, Maurício Nascimento, Antonio Tadeu Rogerio Franco, Vinicius Torres dos Santos, Marcio Silva, Antonio Couto, Gilmar Batalha
Presenter: Givanildo Santos
doi://10.26678/ABCM.COBEF2019.COF2019-0128
Abstract
The Cu-8.5wt% Sn alloy is similar to the UNS C51200 phosphor bronze, a material commonly used in the manufacture of machine elements and electrical contacts. Concomitantly with the solidification of this bronze occurs the formation of a eutectoid mixture (detrimental to subsequent forming processes). In this study was analyzed the influence of the thermal variables of solidification on the microstructure and the (micro)hardness of Cu-8.5wt% Sn alloy. The unidirectional solidification technique was used for the acquisition of thermal data and metallographic analysis was performed with the use of optical microscopy to characterize the microstructure of the material as well as to measure the dendrite arm spacing. Hardness tests were performed on samples from the columnar zone of the casting: six longitudinal samples and six transverse ones. The results showed that the (micro)hardness of the material tends to decrease as the dendrite arm spacing increases, as the tip growth rate decreases or as the cooling rate decreases. There is also a slight decrease in the amount of eutectoid mixture toward locations with higher tip cooling rate.
Keywords
Cu-8.5 wt% Sn alloy, Solidification, Microstructure, hardness, Bronze
