Effect of partial pressure of reactive gas on chromium nitride and chromium oxide deposited by arc ion plating
(1.江西省南昌市江西科技师范学院江西省表面工程重点实验室2.Department of Materials Science and Engineering, Nanchang Institute of Aeronautical Technology, Nanchang 330063, China3.中国科学院金属研究所金属腐蚀与防护国家重点实验室，沈阳110016)
Abstract: The effects of reactive gas partial pressure on droplet formation, deposition rate and change of preferred orientation of CrN and Cr2O3 coatings were studied. For CrN coatings, as nitrogen partial pressure increases, the number and size of droplets increases, the deposition rate initially increases obviously and then slowly, and the preferred orientation of CrN changes from high-index plane to low-index one. For Cr2O3 coatings, with the increase of oxygen partial pressure, the number and size of droplets decreases, the deposition rate decreases and the (300) becomes the preferred orientation. These differences are ascribed to the formation of CrN (with a lower melting point) and Cr2O3 (with a higher melting point) on the surface of Cr target during the deposition of CrN and Cr2O3. Complete coatings CrN or Cr2O3 film can be formed when reactive gas partial pressure gets up to 0.1 Pa. The optimized N2 partial pressure for CrN deposition is about 0.1？0.2 Pa in order to suppress the formation of droplets and the suitable O2 partial pressure for Cr2O3 deposition is approximately 0.1 Pa for the attempt to prevent the peel of the coating.
Key words: chromium nitride; chromium oxide; arc ion plating; reactive gas partial pressure