W-CuO 혼합물을 이용하여 제조된 W-Cu 나노복합분말의 미세구조와 소결거동에 관한 연구

Abstract

Recently, the fabrication process of W-Cu nanocomposite powders has been researched to improve the sinterability by mechanochemical process (MCP), which consists of ball milling and hydrogen-reduction with W- and Cu-oxide mixture. However, there are many control variables in this process because the W oxides are hydrogen-reduced via several reduction stages at high temperature over 800℃ with susceptive reduction conditions. In this experiment, the W-15 wt%Cu nanocomposite powder was fabricated with the ball-milling and hydrogen-reduction process using W and CuO powder. The microstructure of the fabricated W-Cu nanocomposite powder was homogeneously composed of the fine W particles embedded in the Cu matrix. In the sintering process, the solid state sintering was certainly observed around 850℃ at the heating rate of 10℃/min. It is considered that the solid state sintering at low temperature range should occur as a result of the sintering of Cu phase between aggregates. The specimen was fully densified over 98% for theoretical density at 1200℃ for 1 h with the heating rate of 10℃/min.