Response to Thermal Exposure of Ball-Milled Cu-Mg/BO Powder Blends.

The response to thermal exposure of ball-milled Cu-Mg/BO powder blends was investigated in the current study to explore the potential of powder metallurgy route to produce Cu-B alloys. Cu-20Mg alloy powder was mixed with BO and subsequently ball milled for 1 hour. Ball milling alone failed to establish a reaction between Cu-Mg compounds and BO. When the ball-milled powder blend was heated, however, BO was reduced by CuMg <773 K (500 °C). The CuMg intermetallic phase, which has survived until 773 K (500 °C), was involved in the reduction of the remaining BO at still higher temperatures, while excess Mg reacted with B to produce MgB and MgB compounds. Cu-Mg alloy with predominantly the CuMg phase must be utilized to take advantage of the capacity of the CuMg (Cu-43 wt pct Mg) compound to reduce BO at temperatures as low as 773 K (500 °C). Once the Cu-43Mg alloy powder is mixed with BO and the powder blend thus obtained is ball milled and subsequently heated at 500 °C, BO is readily reduced by CuMg to yield Cu, B, and MgO. The latter can be easily removed from the powder blend by acid leaching. [ABSTRACT FROM AUTHOR]