Lead-free Cutting Brass Developed And Its Performance

Most of conventional freeutting brass is the brass which contains Pb element, such as Ifb59~. HPb63?. Such brass is used in mechanism manufacturing widely. After those leaded parts discard as useless, they will pollute circumstance in mny ways. Recently, the developing of nonleaded free utting brass is very necessity with the demanding of envirorunent protecting.The reason for leaded brass?s excellent cutability is that lead particle has not intension and has the role of lubricating at the same time. Our experiment is based on realizing the mechanism of leaded brass?s cutability, considering using silicon and other elements substitute for lead element, and reduce the content of copper, so we gain (P+y) binary phase alloy. And we try to make second phase?Y phase fine and dispersive distributing, in order to make it take the role of break the chips just as lead particle in leaded brass.The samples are received cutting test, and compare their chips withthose of HPb59?, we find that the cutability of nonleaded freeutting is70?096of that of HPb59?. At the same time, we find that the cutabilityis related to the configuration~ distributing~ amount.. character of yphase.The brass?s structure with Fine, dispersive and uniformity distributing..a suited hardness to basal part?P phase is the key of excellent cutability.The sample of nonleaded freeutting brass containing silicon is observed with electron microscope, we find that there is a clearance in the boundary between basal part?P phase and second phase particle?y phase. This indicate that basal part is not combine with second phase particle tightly, just equal to y phase inlaying P phase?s countless holes, this is the principle of the cutability of nonleaded freeutting brass.Considering its practicability of nonleaded freeutting brass, Our?II ?research examine a few of its other performance. Including heat press property-. wearability-. resisting seawater causticity dezincification-. inipulsion toughness and so on. We find that nonleaded freeæ¢'utting brass has preferable synthetical capability and excellent cutability as well, so nonleaded freeæ¢'utting brass can be manufactured as practicability material.