An optimum path to obtain β Cu–Zn–Al by mechanical alloying

• A β Cu–Zn–Al alloy can be obtained from low energy ball milling.
• The temperature of the powder during low energy milling does not surpass 100 °C.
• The optimum path is to mill the three elements simultaneously and continuously.
• A 100% β phase specimen can be obtained after suitable compaction and sintering.
• The martensitic transformation appears only after sintering at 900 °C.

Cu–Zn–Al alloys have been produced by low energy ball milling following six different synthesis paths. In all cases, a mixture of α and β phases have been obtained. Milling for 100 h without interruptions the three elements simultaneously gave the best ratio between the amount of β phase and the milling time. Low temperature thermal treatments to the powders (up to 450 °C) lead to γ phase crystallite growth, with the amount of β phase remaining nearly constant. With anneals at 800 °C the β phase fraction in the powder increased solely to 86%. A sample of pure β phase was obtained only after warm compaction at 680 MPa and sintering at temperatures above 800 °C. In addition, it was necessary to reach temperatures of 900 °C in order to have a material that transforms martensitically.