The nonferrous material that is fit for standard block of hardness for industrial purpose is at present 7-3 brass. But it is inefficient at lower hardness because its variation range gets extensively scattered then.
The present research was conducted to control the hardness of brass and its variation range by replacing some of its zinc contents with such metals as beryllium, manganese, aluminium, and silicon, under various draft of cold rolling and heat treatment.
Stable hardness could be attained around HRB 30 with controlling zinc content of lower hardness materials to 3∼5%. The added elements are in the range of 0.3∼1.0%. These ternary alloys are constructed with α-phase only, of which the standard composition is shown in Table I. The working process of homogenizing, initial rolling, intermediate annealing, final rolling, final annealing, etc. is respectively shown in Table II.
The research has proved that beryllium is the most effective as additive element, and aluminium and manganese come after it with their variation range of hardness at around HRB 30∼40.
