Adding trace amounts of rare earth elements (such as cerium, Ce and lanthanum, La) into the metal matrix of diamond tools enhances their mechanical and overall performance through the following primary mechanisms:

Purifying the matrix alloy interface: The rare earth element Ce can remove impurities such as O, S, and N, and suppress their segregation at the interface, thereby effectively purifying the matrix alloy interface.

Lowering melting points and improving wettability: Ce can lower the melting point of copper (Cu)-based alloys and significantly reduce the contact/wetting angle of liquid copper alloy on diamond, improving the wetting state between the two materials.

Refining grain structure: The addition of rare earth elements functions to refine the microstructure grains, which directly improves the mechanical properties and durability of diamond tools.

Enhancing interfacial bonding: Rare earth La, for example, significantly improves the bonding performance between diamond and the metal matrix, elevating the overall bond strength and operational performance of the tool.