Forming of miniature components from powders by combining field-activated sintering and micro-forming

Micro-FAST is a process concept which scales down conventional FAST to the micro-scale process (dealing with miniature an micro-sized components) and it combines the sintering process with a micro-forming process to enable shaping components under coupled multi-fields actions and hence, to achieve high-density, near-net-shaped components with high efficiency. The main techniques developed for overcoming the barriers for the applications of FAST at the miniature/micro-scales include: (i). Directly pressing/forming loose powders in the die without using binders; (ii). Combining heating and shaping to enable complex shapes/features; and (iii). Dedicatedly controlling fusion bonding and material’s plastic flow to enable high-quality forming. Forming from powders without using binders significantly shortened the process cycle, which also led to high-purity of the parts formed; Combining forming and sintering has led to high-density components produced as well as achieving complex-shaped components; Large current density (e.g., >100~400 KA/cm-2) enables very high heating rates and using small volumes of materials results in high cooling rates, leading to much shorter forming/sintering cycles which enables consolidation of micro/nanocomposites into bulk-sized components while also preserving their micro/nanostructures.