LATTICE-PARAMETERS AND THERMAL-EXPANSION OF TI(CXN1-X), ZR(CXN1-X), HF(CXN1-X) AND TIN1-X FROM 298-K TO 1473-K AS INVESTIGATED BY HIGH-TEMPERATURE X-RAY-DIFFRACTION

The thermal expansion values of the fee phases Ti(CxN1-x), Zr(CxN1-x) and Hf(CxN1-x) with [C+N]/[Me]similar to 1 and TiN1-x with [N]/[Ti]=1.0 to 0.67 were determined from lattice parameter measurements made with high-temperature X-ray diffraction (HTXRD) in the temperature range of 298-1473 K. Stoichiometric titanium carbonitrides, zirconium carbonitrides and hafnium carbonitrides obey the Vegard rule up to 1473 K quite well, i.e. at any temperature up to 1473 K the lattice parameter behaves linearly between TiN-TiC, ZrN-ZrC and HfN-HfC, respectively. The lattice parameter of titanium nitride is also a linear function of the nitrogen/metal ratio in the temperature range investigated.