Structure and properties of new ecological copper alloys for fittings

The article presents the results of studies concerning the selection of the chemical composition of the new ecological copper alloys for fittings. It was analyzed, among other things, the impact of the content of bismuth, aluminum, iron and boron. Their solidification process was characterized on the grounds of thermal and derivative analysis (TDA). Also the microstructure and mechanical properties were analyzed. Casting properties were determined by the castability spiral test. It was found that zinc is an essential component of the tested group of alloys, determining the course of their crystallization, phase composition and microstructure. There was no significant effect from the other elements on the course of crystallization. The obtained results revealed that bismuth is the element of the strongest impact on the castability changes. The formulated alloys surpass the commonly used standardized alloy intended for components of fittings, namely MO59, in terms of casting and mechanical (hardness) properties