Microstructural and electrical properties of AlN–CoCrFeMnNi cermet obtained by hot pressing

AlN and equimolar ratio of gas atomized CoCrFeMnNi HEA powders were used to prepare AlN–CoCrFeMnNi cermets by ball milling followed by hot pressing sintering at 1240 °C for 2 h. The microstructure characteristics and electrical properties of the cermets were investigated. The sintered cermet bulks were composed of a FCC-structured CoCrFeMnNi solid solution binder phase, AlN phase, and a small amount of Cr7C3 type carbide. No obvious interfacial reaction occurred between AlN and CoCrFeMnNi HEA. The resistivity of AlN–CoCrFeMnNi cermets nonlinearly increased with increasing AlN content and temperature. A conductivity model of AlN–CoCrFeMnNi cermets at room temperature and 600 oC was established based on the generalized effective medium (GEM) equation. Results indicated that AlN–CoCrFeMnNi cermets had a typical percolation threshold phenomenon, which allowed to continuously regulate their resistivity between 102 μΩ cm to 103 μΩ cm as AlN was in the range of 10–50 wt% under room temperature. Therefore, the AlN–CoCrFeMnNi cermets are promising materials for applications in the e-cigarette field.