A study of the machinability of leaded brass, with copper content ranging 52∼60% and additional 1∼4% lead ingredient, is reported in this paper, performed with respect to cutting resistance, surface roughness and chip formation among others, with particular reference to the part of copper content and lead content in affecting the machinability of the leaded brass piece which was used in the experiment as free cutting brass.
The results are summarized as follows:
With lead content as small as 1%, cutting resistance is smallest with brass of 58∼59%, copper content where phases α and β are co-existing, while cutting resistance is largest with brass of 53∼56% copper content where the phase is in transition stage from α+β to β. On the whole cutting resistance decreases with increase of lead content, and keeps up nearly constant value regardless of copper content.
Cutting resistance decreases with the rise of side rake angle of tools and keeps up nearly constant value at the side rake angle 20°. With increase of lead content to 3∼4% cutting resistance becomes independent of the side rake angle.
The roughness of the cut surface is fairly within the theoretical roughness of the feeding tool mark. Either copper content or lead content seems to have nothing to do with the surface roughness.