Cutting Silicon Brass Performance

This paper explore a new type of cutting brass by adding microelement Al, Ni, Sn and La to the Cu-Zn-Si-P alloy for replacing toxic leaded brass and expensive bismuth brass. Meanwhile, the impact of microelement on the alloy structures and properties are discussed, and influence law and mechanism are analyzed. Experimental procedure are listed: (1) The alloy are manufactured by melting—hot extrusion- cold-drawn method; (2) The composition, structure and surface morphology are tested using optical microscope, XRD, SEM, EDS. (3) The hardness, cut ability, mechanical properties are tested by Brinell hardness, tensile testing and machine cutting experiment. (4) The corrosion of the alloy is quantified by sea water corrosion and zinc corrosion. The conclusions are as follows:When the silicon content in the Cu-Zn-Si-P -Sn-Ni-La alloys increase, the strip, needle and clawαphases gradually decreased, but the gray and blackβphase , the white-dot brittle compoundβ′and the compound of Cu9Si gradually increased. It is these hard-brittle phase and the compounds improved the cutting properties of alloys in some extent. When theαphase,βphase, the white-dotsβ` phase and the compound of Cu9Si achieve the best combination, the Cu-Zn-0.5%Si-P–Sn-Ni–La alloy has good mechanical properties, machinability and corrosion resistance.The test results of Cu-Zn-0.5%Si-P–Sn-Ni–La alloy shows: Under extrusion state, the cutting, hardness, tensile strength and elongation are 80%, 140 HB, 602 MPa, 26.67% respectively. The hardness, tensile strength elongation are 165HB,617MPa and 16 % respectively under cold-drawn state, but these test results are 128 HB, 569 MPa and 29 %under the annealed state.After the testing of Cu-Zn-0.5%Si-P-Sn-Ni-La alloy by sea water corrosion and zinc corrosion experiments, we found that the extrusion average weight loss rate and cold-drawn are 0.08 g/m~2day and 0.064 g/m~2 day under sea water corrosion. Under the dezincification: the average dezincify of cast is 40.7μm, extrusion is 96.54μm, cold-drawn is 92.04μm and the annealed is 63.32μm. These results are better than HPb59-1 brass under the same state.Cu-38.24%Zn-0.5%Si-0.1%P-0.4%Sn-1%Ni-0.06%La alloy has a good mechanical properties,corrosion resistance and machinability, which achieved the desired targets and can replace widely-used HPb59-1 brass .