新規なニッケルブリー白色銅合金の開発

摘要

It is known that the Cu-24 mass percent Zn-13 mass percent Ni alloy, which is called as Nickel Silver, has been widely used in the manufacture of zippers, button, and spectacle frames. In recent years, it has been reported that Ni may cause skin allergies to those who are in constant contact with alloys containing Ni. In order to develop a new nickel-free copper alloy with the same white color as that for Nickel Silver, we examined the effect of additional elements on copper alloy's color. The color properties, i.e., a*and b*values of the Cu-Zn-Mn and Cu-Zn-Ti alloy can be changed freely by controlling the concentrations of Zn, Mn and Ti elements. The Cu-5 approx 25 mass percent Zn-10 mass percent Mn and Cu-10 mass percent Zn-3.8 mass percent Ti alloys have the same white color as that for Nickel Silver and the lowest season cracking susceptibility which is nearly the same as that for Cu-15 mass percent Zn alloy, in addition to the absence of irritations resulting from Ni.