アークPVD法によるCr-B-N，Cr-C-NおよびCr-O-N系皮膜の耐熱性と微細構造

抄録

Using the PVD arc ion plating method, Cr-B-N, Cr-C-N, and Cr-O-N coatings with different B, C, and O contents, and CrN coatings were prepared. Thermal stability of the coatings during annealing in air at temperatures of 473-1073 K was investigated.
X-ray diffraction measurements showed that all diffraction peaks of cubic CrN phase sharpened and shifted to a higher angle as the annealing temperature increased. At temperatures higher than 773 K, the grain sizes of most coatings became larger, and hardness decreased. The CrN and the Cr-C-N coatings respectively began decomposing at temperatures higher than 773 K and 873 K. As the amount of the third element increased, changes of the diffraction peaks decreased and the decrease of hardness was restricted. The grain size and hardness of the Cr-O-N coating with the most O content changed little after annealing.
TEM observations revealed that the apparent grain growth of the CrN coating occurred during annealing, but fine microstructures of CrB-N, Cr-C-N, and Cr-O-N coatings were almost unaffected by annealing. Nanometer-scale periodic lines of the Cr-O-N coating did not change after annealing.
Subsequent AES analysis revealed that the periodic lines of the Cr-O-N coating indicated a change of O concentration. The period was maintained after annealing at 873 K.