Hydrogen-reduction behavior and microstructural characteristics of WO₃-CuO powder mixtures with various milling time

Microstructure and hydrogen reduction behavior of WO₃-CuO with different milling time are discussed in terms of characteristic of hygrometry curve and W particle size of reduced W-Cu composite powders. With increased milling time, the peak temperatures for the reduction of CuO and WO₃ in hygrometry curve are shifted to low temperatures and the peaks are changed to sharp shape. Microstructural analysis revealed that the hydrogen-reduced powder with milling time of 20 h showed smaller particle size than that of 1 h. The change of reduction behavior and particle size is discussed based on the refinement of oxide powders and resultant increased surface area as well as reduction process of WO₂ by CVT.