Fabrication of high performance densified nanocrystalline bulk thermoelectric materials using high pressure sintering technique

摘要

The present invention provides a method for the fabrication of high performance densified nanocrystalline bulk thermoelectric material, comprising: (1) preparing a thermoelectric alloy nanopowders by a ball milling process to achieve an average crystal size of 5 -30 nm, and (2) preparing the nanocrystalline bulk thermoelectric material by high pressure sintering at a temperature of 0.25 - 0.8T m under a pressure of 0.8 - 6.0 GPa for 10 - 120 minutes, to achieve a relative density of 90 - 100 % and an average grain size of 10 - 50 nm. The method is easy to operate and allows the production of a thermoelectric material with a ZT value higher than 2. In addition, the method can ensure both good thermoelectric properties and high density, and therefore have important applications for energy industry.