Low lead brass alloy and method for producing product comprising the same

Abstract

A low lead brass alloy and a method for producing a product comprising the low lead brass alloy are proposed. The low lead brass comprises 0.05 to 0.3 wt % of lead (Pb); 0.3 to 0.8 wt % of aluminum (Al); 0.01 to 0.4 wt % of bismuth (Bi); 0.1 to 0.15 wt % of microelements; and more than 97.5 wt % of copper (Cu) and zinc (Zn), wherein copper is in an amount ranging from 58 to 70 wt %.

1 . A low lead brass alloy, comprising:
 0.05 to 0.3 wt % of lead;   0.3 to 0.8 wt % of aluminum;   0.01 to 0.4 wt % of bismuth;   0.1 to 0.15 wt % of microelements; and   more than 97.5 wt % of copper and zinc, wherein the copper is in an amount ranging from 58 to 70 wt %.   
     
     
         2 . The low lead brass alloy of  claim 1 , wherein the lead is in an amount ranging from 0.15 to 0.25 wt %. 
     
     
         3 . The low lead brass alloy of  claim 1 , wherein the aluminum is in an amount ranging from 0.5 to 0.65 wt %. 
     
     
         4 . The low lead brass alloy of  claim 1 , wherein the bismuth is in an amount ranging from 0.1 to 0.2 wt %. 
     
     
         5 . The low lead brass alloy of  claim 1 , wherein the copper is in an amount ranging from 62 to 65 wt %. 
     
     
         6 . The low lead brass alloy of  claim 1 , further comprising less than 0.8 wt % of phosphorus. 
     
     
         7 . The low lead brass alloy of  claim 6 , wherein the phosphorus is in an amount ranging from 0.4 to 0.8 wt %. 
     
     
         8 . The low lead brass alloy of  claim 1 , wherein the microelements are at least ones of rare earth elements and unavoidable impurities. 
     
     
         9 . A method for producing a product comprising the low lead brass alloy of  claim 1 , comprising the steps of:
 preheating the low lead brass alloy and foundry return to a temperature ranging from 400° C. to 500° C.;   melting the low lead brass alloy and the foundry return to boiling to form a molten copper liquid;   preheating a mold to 200° C. and placing sand core into the mold;   casting the molten copper liquid into the mold at a temperature ranging from 1010 to 1060° C. to obtain a casting part; and   releasing the casting part from the mold.   
     
     
         10 . The method of  claim 9 , further comprising a step of preparing the sand core by mixing one or more selected from the group consisting of rounded sand having particle diameters respectively ranging from 40 to 70 meshes, 50 to 100 meshes and 70 to 140 meshes with a resin and a curing agent. 
     
     
         11 . The method of  claim 9 , further comprising a step of performing a sand washing treatment on the foundry return prior to preheating, so as to remove sand and iron wires. 
     
     
         12 . The method of  claim 9 , wherein the low lead brass alloy and the foundry return are at a weight ratio ranging from 6:1 to 9:1. 
     
     
         13 . The method of  claim 9 , wherein step of melting further comprises adding refining slag. 
     
     
         14 . The method of  claim 13 , wherein the refining slag is preheated to a temperature above 400° C. prior to adding the refining slag. 
     
     
         15 . The method of  claim 13 , wherein the refining slag is added in an amount ranging from 0.10 to 0.15 wt % based on a total weight of the low lead brass alloy and the foundry return. 
     
     
         16 . The method of  claim 9 , wherein the step of casting is performed for 3 to 8 seconds. 
     
     
         17 . The method of  claim 9 , wherein the step of casting is performed in batches, and a casting amount in each of the batches is about 1 to 2 kilograms. 
     
     
         18 . The method of  claim 9 , wherein the step of releasing is performed for 10 to 15 seconds after step (d) is completed or till the casting part is not red and hot. 
     
     
         19 . The method of  claim 9 , further comprising: after the step of releasing, cooling the mold and maintaining the mold at a temperature ranging from 180 to 220° C. 
     
     
         20 . The method of  claim 19 , wherein the step of cooling is performed using a graphite liquid. 
     
     
         21 . The method of  claim 20 , wherein the mold is immersed in the graphite liquid for 3 to 8 seconds. 
     
     
         22 . The method of  claim 20 , wherein a specific weight of the graphite liquid ranges from 1.02 to 1.10. 
     
     
         23 . The method of  claim 20 , wherein the graphite liquid is at a temperature ranging from 25 to 45° C. 
     
     
         24 . The method of  claim 9 , further comprising: after the step of releasing, cleaning the mold and spraying the graphite liquid on a surface of the mold.