The influence of phosphorus microalloying on the structure formation of CuZn32Mn3Al2FeNi multicomponent brass

Phosphorus in brass can have both a positive effect, such as improving mechanical properties, increasing corrosion resistance and machinability, and a negative effect, such as adversely affecting weldability and causing cracking. The study of the role of phosphorus in the processes of brass structure formation is of practical relevance, since it helps optimise the properties of the material, reduce the risk of defects, improve treatment processes and control properties and quality. The work covers the study of the role of phosphorus in brass, the need to control its content during production by limiting the share of secondary use. The study revealed the possibility of a positive effect of modifying copper alloys with phosphorus in order to improve performance properties, as well as the prospects of using phosphorus as a safe replacement for lead in brass. The authors assessed the content and distribution of phosphorus impurity at a concentration of 0.005 % in a brass sample of the CuZn32Mn3Al2FeNi grade, studied the nature of its interaction with other components of the alloy and the changes occurring at different temperatures of heat treatment. It has been found that phosphorus actively participates in diffusion processes and forms phosphides in both defective and defect-free blanks. When heated to the hot deformation temperature range, phosphorus redistribution occurs, phosphide locally dissolves, and metastable inclusions form. Due to differences in the concentration of elements in areas adjacent to the phosphide, the brass structure changes leading to the formation of areas different from the matrix β-phase. Manganese phosphide in brass can improve its mechanical properties and cutting ability, but an excess of this compound can lead to problems with strength, crack resistance, and moulding.