Effect of addition of tin on the microstructure and machinability of α-brass

ABSTRACT

This study was aimed at developing lead-free brass alloys with the goal of substituting lead element with tin. For this purpose, lead-free alloys with tin were developed and the microstructure, hardness and machining behaviour of the Cu–30%Zn alloy was compared with Cu–30%Zn–x%Sn (x =  1.2, 3.2, 5.4, 8, 11.4, 13.9, 17.4). The results showed that the addition of Sn to single-α phase brass led to the formation of duplex (α + β′) brass and then the formation of (β′ + Ɣ ) brass both with increased hardness. In addition, the addition of Sn to Cu–30%Zn alloy led to the decrement of equivalent machining forces (F_m), surface roughness and also the promotion of chip fragmentation due to the formation of the β′ phase, which is an improvement in machinability.

KEYWORDS:

• Lead-free brass
• alpha brass
• tin
• hardness
• machinability
• chip formation

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

Hamid Doostmohammadi http://orcid.org/0000-0003-1779-8728