Atom probe tomography investigation of sintered transition metal carbonitride - A Zr(C,N) study

Abstract

Zirconium based nitrides, carbides and carbonitrides are highly technological compounds which received during the 1950s and 60s huge interest due to their combination of metal and refractory properties. The interest reiterated recently due to the need of compounds with high electrical conductivity, corrosion and oxidation resistance, and neutron transparency with the rise of mobility electrification and nuclear energy. Sintered Zr(C,N) is investigated with CHN elemental analysis combined with atom probe tomography (APT) to evaluate the composition and homogeneity of carbon and nitrogen from the bulk down to the nanometer scale. Results have shown a strong nitrogen loss and an enrichment in carbon which diffused from the graphite die and punch. Nevertheless, the composition is homogenous in the sample. Atom probe tomography suggests that the sintered alloy is sub-stoichiometric with carbon and nitrogen homogeneously distributed within the grain. The stoichiometry calculated corresponds to the estimation by Vegard’s law.