Combustion synthesis of refractory and hard materials: A review

 Guanghua Liu a,, Jiangtao Li a, Kexin Chen b

a Technical Institute of Physics and Chemistry, Key Laboratory of Functional Crystals and Laser Technology, Chinese Academy of Sciences, Beijing 100190, China
b Department of Materials Science and Engineering, State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084, China

Combustion synthesis is widely used for preparing various refractory and hard materials, including alloys,
intermetallics, ceramics, and cermets. The unique reaction condition in combustion synthesis with
extremely-high temperature and fast heating/cooling rate offers the products interesting microstructures
and superior mechanical properties. In comparison with conventional powder metallurgy approaches, combustion
synthesis exhibits the advantages of short processing time, less energy consumption, and lower cost,
thus providing a more efficient way to produce refractory and hard materials.
This article reviews recent progress in combustion synthesis of refractory and hard materials, with an emphasis
on the results reported in the last decade. Both the synthesis of powders and direct fabrication of bulk materials
are discussed. For the synthesis of powders, results in two aspects are reviewed, viz. synthesis of ultrafine and especially
nano-sized powders by thermal reduction reactions or post chemical etching, and synthesis of nitride and
carbide powders in air. For direct fabrication of bulk materials, two techniques are involved, viz. combustion synthesis
with simultaneous densification assisted by amechanical or gas pressure, and combustion synthesis casting
in a high-pressure Ar atmosphere or in a high-gravity field.