Compaction and sintering response of mechanically alloyed Cu–Cr powder

The present paper discusses the powder processing techniques of mechanically alloyed Cu–Cr powder. Mechanical alloying is required to obtain a nano-scale homogeneous mixture of Cu and Cr. Two processes to prepare Cu–Cr contacts are proposed from the present study for obtaining compacts having better properties. While the explosive compaction of the mechanically alloyed powder forcibly fills the pores to show excellent density and electrical conductivity, application of Cu coating to the mechanical alloyed powder gives a short-circuit diffusion path during sintering and thus, shows the best combination of properties compared to the presently used Cu–Cr compacts. Both the processes show near theoretical density, exceptionally high electrical conductivity and comparable hardness. Moreover, both the processes change the sintering process of Cu–Cr compacts from liquid phase sintering to solid-state sintering, thus making the process more energy efficient.

The paper discusses two novel processes to prepare Cu–Cr contacts, suitable for contact materials. While the explosive compaction of the mechanically alloyed powder forcibly fills the pores, application of Cu coating to it gives a short-circuit diffusion path during sintering to show excellent properties. Both processes show exceptionally high density and electrical conductivity, apart from reducing sintering temperature by 300 K, thus making the process more energy efficient.Figure optionsDownload as PowerPoint slide