Abstract
The effect of adding additional elements such as manganese, silicon, zinc, tin, lead, beryllium, phosphorus, magnesium, cobalt, titanium, boron and chromium to the copper-aluminium-nickel-iron quaternary alloys on the microstructure and the mechanical properties have been investigated. From the results it was found that the effects of adding the above mentioned elements are classified into the following three groups from their behaviors:
(a) The elements that dissolve in the α solid solution and, when exceeding the solubility limit, cause the alloy to precipitate the (α+δ) eutectoid and increase the brittleness. Tin, beryllium, silicon, manganese and zinc are in this group, of which tin, beryllium and silicon produce a detrimental effect.
(b) The elements that produce hard spots or deteriorate the castability. Lead, chromium, boron, phosphorus and magnesium are in this group.
(c) No effect was observed when cobalt was added, which was considered to have an effect as a precipitation hardening constituent, perhaps owing to the small amount added.
