Cu–Mo composite powders obtained by combustion–coreduction process

• Cu–Mo composite powder is prepared by metal oxide coreduction in combustion mode.
• The coreduction mechanism was explored by thermocouple and copper-wedge techniques.
• At using combined Mg/C reducers, carbothermal reduction preceded the Mg reduction.
• Weak reducer (C) reduces CuO to Cu & MoO3 to MoO2 then MoO2 is reduced by molten Mg.
• The presence of carbon allows performing reduction in controlled combustion mode.

Cu–Mo composite powders were prepared by coreduction of CuO and MoO3 oxides with Mg–C combined reducer in combustion process by applying reactions' coupling approach. Combustion peculiarities, interaction mechanism, as well as phase- and microstructure formation laws were explored by thermocouple and copper-wedge techniques combined with XRD, SEM and EDS analysis methods.It was shown that in the reaction's coupling process carbon influences not only on the thermal regime, products phase and microstructure characteristics, but also on the reaction mechanism. The detailed investigation of combustion thermograms and phase composition of quenched products from different areas of combustion wave asserted that carbothermal reduction preceded the magnesiothermal one, as a result of which a sharp decreasing of combustion velocity occurs. Such behavior of reaction system under study conforms to the model for proceeding of two sequential exothermic reactions being spatially separated (so-called splitting mode). The latter allows performing reaction in slow and controlled combustion regime.

Figure optionsDownload as PowerPoint slide