A Novel W-Skeleton-Reinforced Al Matrix Composite by Consolidating a Newly Developed Core–Shell-Structured W-Coated Al Powder

A uniform core–shell-structured W-coated Al powder was efficiently prepared by using fluidized bed chemical vapor deposition. The deposited W prevented the defluidization of Al powder and thereby enabled the controlled preparation of core–shell powder with different W-contents. Both the shell and activated sintering of the deposited nano-sized W particles contributed to the formation of a network W-skeleton in the composite. Compared with the W particles and/or aggregates formed from the powder mixture, the formation of W-skeleton which has better interface bonding with the Al matrix may create an excellent and continuous seepage pathway for electrons, resulting in superior electrical conductivity. In addition, the uniform W-skeleton structure led to enhanced tensile strength but a lower ductility. However, the negative response of continuous W-skeleton to the ductility can be ignored when the width of W-skeleton was in the 200 to 300 nm range. The W-content was optimized at 5 wt pct to obtain a good combination of mechanical properties and electrical conductivity.