Study on the Microstructures and Properties of the Lead-free Easy-cutting BiAI-brass

摘要

Traditional lead brass products pollute the environment and do harm to the human health.Fabrication of the new kind of the brass without lead is an urgent task.Bi-brass is the most popular lead-free easy-cutting brass.However,its mechanical and hot-working properties are not satisfied.In present paper,aluminum element was added into the Bi-brass alloy in order to improve the alloy's mechanical and hot-working property.Experiment results showed that the aluminum can increase the surface tension of the Bi and change the existing morphology of Bi from film-like into particle-like.Therefore,the ingot's hot-working property is excellent.Experiment results showed that even the extrusion ration reaches 256,the ingot still can be extruded into rod successfully.Experiment results also indicated that the homogenizing annealing treatment on the ingot and addition of the rare earth La did not improve the mechanical properties or the machinability.