Microstructure and properties of lead-free brasses using post-processing heat treatment cycles

Abstract

We report the tailoring of the microstructure of lead-free brasses with a view to improving their machinability via the controlled augmentation of the β-phase. This should be performed while keeping the mechanical properties within the EN standard, as β-phase augmentation can lead to embrittlement. Twenty seven heat treatment protocols were performed in order to transform the microstructure and consequently modify the properties of three lead-free brasses. The most successful heat treatment was chosen for each studied alloy according to the above criteria. The selected protocols led to a combination of β-phase augmentation with mechanical properties conforming to standards providing a promising ground for improved machinability performance.

This paper is part of a Themed Issue on Brass Alloys.

Keywords:

• Lead-free brass
• Mechanical Properties
• Heat treatment
• Microstructure
• β-phase
• Fractography

Acknowledgements

The authors wish to express special thanks to the Administration and Quality Division of FITCO S.A. for the continuous support and providing samples for the current investigation. Also special thanks are addressed to Mr A. Rikos for his valuable contribution in the metallographic preparation and Mr A. Vazdirvanidis for the valuable comments and discussion.

ORCiD

G. A. Pantazopoulos http://orcid.org/0000-0002-6416-3760

A. S. Paipetis http://orcid.org/0000-0001-9668-9719