Bronze Bonds Used in Diamond Tools' Manufacture

The bond material used in metal-bonded diamond tools can be Cu-based alloy, Co-Ni alloy, Fe-based alloy and carbide-based alloy. Bronze bond material is a kind of Cu-based alloy, and is widely used in metal-bonded diamond tools’ manufacture.

The bronze bond has high strength and hardness. Its shrinkage is small and it is easy to generate dispersed shrinking holes. In addition, the thermal conductivity of Cu is only lower than the expensive Ag and is higher than other metals. This helps to decrease the temperature generated in the diamond tools’ working process and avoid burns on the workpiece.

The often adopted metal materials in the bronze bond are the powders of Cu, Sn, Zn and Ag. Sometimes some non-metal materials, such as graphite, are also added. As the objects to be processed and their processing requirements vary, the composition of the bronze bond may also be different. According to the number of metal elements in it, bronze bonds can be categorized into binary-alloy series, ternary-alloy series and multi-alloy series.

1) Binary-Alloy Series: In this series, the Cu-Sn alloy is the most common used. Some graphite is also added into the bonds of this kind.

2) Ternary-Alloy Series: This series is composed by adding a third metal element into the binary-alloy series bonds. The third metal element can be Ag, Ni, Zn, Fe, Pb, etc.

3) Multi-Alloy Series: This series bonds base on the Cu element, and have 3 or more other metal elements, such as Sn, Zn, Pb, Ag, Ni, Co, Fe, Cd, Mo, etc.