HfB2 and Hf–B–N hard coatings by chemical vapor deposition
2005; Elsevier BV; Volume: 200; Issue: 22-23 Linguagem: Inglês
10.1016/j.surfcoat.2005.11.040
ISSN1879-3347
AutoresS. Jayaraman, J. E. Gerbi, Yu Yang, D.Y. Kim, Amitava Chatterjee, Pascal Bellon, Gregory S. Girolami, Jean‐Pierre Chevalier, John R. Abelson,
Tópico(s)Boron and Carbon Nanomaterials Research
ResumoHard, dense and conformal hafnium diboride (HfB2) thin films were obtained by CVD from the precursor Hf[BH4]4 at deposition temperatures ≤ 350 °C. As-deposited films were X-ray amorphous but transformed to a nanocrystalline structure after being annealed at 700 °C. Amorphous HfB2 films exhibited a respectable hardness of 20 GPa; the hardness increased in the nanocrystalline state to 40 GPa. Ternary Hf–B–N films, which consisted of a mixture of HfB2, HfN and BN were obtained by adding atomic nitrogen to the growth flux. The formation of the softer a-BN phase produced a drop in the hardness and modulus values. A multilayer HfB2/Hf–B–N exhibited a good combination of high hardness (33 GPa) and low elastic modulus (300 GPa).
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