Research on microstructure and performance of silicon brass with different phase composition

The test techniques of OM、XRD and TG/DTA were used to study the microstructure, cutting properties and dezincification corrosion resistance systematically of the lead-free silicon brass with different phase composition, namely (α+β), β and (β+γ). Results showed the cutting force of silicon brass with the matrix of (α+β) phases was low enough, however it's chip morphology was dissatisfactory, while the average thickness of dezincification layer was 438.12μm, which was the biggest; while the silicon brass with the matrix of (β+γ) phases had the worst chip morphology and the highest Brinell hardness, namely 273.7HB, which meanses the highest cutting force, increasing tool wear and reducing the tool life; the silicon brass with just single phase β had higher cutting force, but the smaller roll chips, which was the best chip morphology, meanwhile it performed the minimum average dezincification layer, Specifically 262.94 μm, during the dezincification corrosion resistance test. therefore, the silicon brass with just single phase β had the best comprehensive properties, brass with the matrix of (β+γ) phases is not suitable for cutting brass, while the cutting performance and corrosion resistance of the brass with (α+β) phase are yet to be improved.