Lead-free free-cutting silicon brass alloy

Abstract

The present invention supplies a lead-free free-cutting silicon brass alloy with high zinc which preferably comprises 35.0 to 42.0 wt % Zn, 0.1 to 1.5 wt % Si, 0.03 to 0.3 wt % Al, 0.01 to 0.36 wt % P, 0.01 to 0.1 wt % Ti, 0.001 to 0.05 wt % rare earth metals selected from the group consisting of La and Ce, 0.05 to 0.5 wt % Sn, and/or 0.05 to 0.2 wt % Ni, and the balance being Cu and unavoidable impurities. The invented alloy is excellent in castability, weldability, cuttability, electroplating properties, corrosion resistance, mechanical properties. The alloy is especially applicable in castings which need cutting and welding under low pressure die casting, such as castings for faucet bodies in the water supply system. The alloy is also suitable for use in components which are produced from casting ingots by die forging.

1 . A lead-free free-cutting silicon brass alloy comprising: 35.0 to 42.0 wt % Zn, 0.1 to 1.5 wt % Si, 0.03 to 0.3 wt % Al, 0.01 to 0.36 wt % P, 0.01 to 0.1 wt % Ti, 0.001 to 0.05 wt % rare earth metals selected from the group consisting of La and Ce, 0.05 to 0.5 wt % Sn, optionally 0.05 to 0.2 wt % Ni, and the balance being Cu and unavoidable impurities, wherein an elongation rate of casting of the alloy is greater than 10%, hardness of the alloy is in a range of HRB 55 to 75, and a bending angle of strip samples of the alloy is more than 55°. 
   
   
       2 . The lead-free free-cutting silicon brass alloy of  claim 1  comprising 39.00 to 42.00 wt % Zn, and 0.1 to 0.3 wt % P. 
   
   
       3 . The lead-free free-cutting silicon brass alloy of  claim 1 , comprising 39.00 to 42.00 wt % Zn, 0.1 to 0.2 wt % Si, 0.15 to 0.3 wt % P, 0.05 to 0.1 wt % Sn, 0.05 to 0.1 wt % Ni and 0.05 to 0.1 wt % Ti. 
   
   
       4 . The lead-free free-cutting silicon brass alloy of  claim 1 , comprising 39.00 to 42.00 wt % Zn, 0.1 to 0.5 wt % Si, 0.15 to 0.25 wt % P, 0.05 to 0.2 wt % Sn, and 0.001 to 0.01 wt % rare earth metals selected from the group consisting of La and Ce, and further comprising 0.05 to 0.4 wt% Mg. 
   
   
       5 . The lead-free free-cutting silicon brass alloy with high zinc of  claim 1 , comprising 40.00 to 42.00 wt % Zn, 0.1 to 0.2 wt % Si, 0.05 to 0.3 wt % Mg, 0.01 to 0.3 wt % P, 0.1 to 0.3 wt % Sn and 0.05 to 0.1 wt % Ni and further comprising 0.05 to 0.3 wt% Mg. 
   
   
       6 . The lead-free free-cutting silicon brass alloy of  claim 1  comprising 40.00 to 42.00 wt % Zn, 0.2 to 0.5 wt % Si, 0.01 to 0.1 wt % P, 0.1 to 0.3 wt % Sn, 0.05 to 0.15 wt % Ni, and 0.001 to 0.04 wt % rare earth metals selected from the group consisting of La and Ce, and further comprising 0.1 to 0.25 wt% Mg. 
   
   
       7 . A lead-free free-cutting silicon brass alloy comprising: 35.0 to 42.0 wt % Zn, 0.1 to 1.5 wt % Si, 0.03 to 0.3 wt % Al, 0.01 to 0.36 wt % P, 0.01 to 0.1 wt % Ti, 0.001 to 0.05 wt % rare earth metals selected from the group consisting of La and Ce, 0.05 to 0.5 wt % Sn, optionally 0.05 to 0.2 wt % Ni, and the balance being Cu and unavoidable impurities. 
   
   
       8 . The lead-free free-cutting silicon brass alloy of  claim 7  comprising 39.00 to 42.00 wt % Zn, and 0.1 to 0.3 wt % P. 
   
   
       9 . The lead-free free-cutting silicon brass alloy of  claim 7 , comprising 39.00 to 42.00 wt % Zn, 0.1 to 0.2 wt % Si, 0.15 to 0.3 wt % P, 0.05 to 0.1 wt % Sn, 0.05 to 0.1 wt % Ni and 0.05 to 0.1 wt % Ti. 
   
   
       10 . The lead-free free-cutting silicon brass alloy of  claim 7 , comprising 39.00 to 42.00 wt % Zn, 0.1 to 0.5 wt % Si, 0.15 to 0.25 wt % P, 0.05 to 0.2 wt % Sn, and 0.001 to 0.01 wt % rare earth metals selected from the group consisting of La and Ce, and further comprising 0.05 to 0.4 wt% Mg. 
   
   
       11 . The lead-free free-cutting silicon brass alloy of  claim 7 , comprising 40.00 to 42.00 wt % Zn, 0.1 to 0.2 wt % Si, 0.01 to 0.3 wt % P, 0.1 to 0.3 wt % Sn and 0.05 to 0.1 wt % Ni, and further comprising 0.05 to 0.3 wt% Mg. 
   
   
       12 . The lead-free free-cutting silicon brass alloy of  claim 7  comprising 40.00 to 42.00 wt % Zn, 0.2 to 0.5 wt % Si, 0.01 to 0.1 wt % P, 0.1 to 0.3 wt % Sn, 0.05 to 0.15 wt % Ni, and 0.001 to 0.04 wt % rare earth metals selected from the group consisting of La and Ce, and further comprising 0.1 to 0.25 wt% Mg..