Structure Formation Processes During Explosive Welding of Copper and Molybdenum: A Research Study

Abstract

The present study investigates samples of Cu-Mo composite material produced through explosive welding. The microhardness of these samples is measured and their structures are analyzed using optical and electron microscopy methods. Copper and molybdenum regions are mapped at the Cu-Mo boundary. The analysis reveals a complex fractal line and dark areas at this boundary, indicating the formation of a new phase.
 Microhardness measurements indicate that the hardness of both copper and molybdenum increases in comparison to standard values for annealed samples of copper and molybdenum, respectively. Furthermore, the hardness of molybdenum increases at the interface with copper, which may also suggest the formation of a new phase.
 The electron microscopy analysis and mapping of copper and molybdenum regions at the Cu-Mo interface confirm the presence of a new phase, which is referred to as "forced eutectic." This is because copper and molybdenum do not typically form solid solutions, eutectics, or intermetallic compounds under equilibrium conditions. The new phase exists only under nonequilibrium conditions.