Reactive Magnetron Sputtering of ZrO2/Al2O3 Coatings: Alumina Content and Structure Stability
DOI:
https://doi.org/10.6000/2369-3355.2015.02.02.4Keywords:
Stabilized Zirconia, Thin coatings, Magnetron sputtering, Hardness, thermal treatmentsAbstract
Ternary zirconia-alumina coatings with different compositional ratios, ranging from pure zirconia to 50% alumina content, were deposited by reactive sputtering from two targets, Zr and Al, in argon-oxygen mixtures. The coating composition was controlled by the Zr/Al target power ratio provided by two pulsed-DC power supplies. The coatings were ~1 µm thick and they were deposited on floating potential substrates at a temperature of 650±3K.
XRD indicated that the pure zirconia coatings possessed a monoclinic structure with a grain size of 35-40 nm. Adding alumina to the zirconia coating stabilized the cubic zirconia phase and decreased the grain size to 10-15 nm. The alumina phase in the coatings remained amorphous. The hardness of the nanocomposite structure increased from 11.6±0.5 GPa to 16.1±0.5 GPa for an alumina content of 17%. At higher alumina concentrations, the zirconia phase became amorphous and the hardness decreased to 10-11 GPa.
Structure stability of the zirconia-alumina coatings was studied by measuring the coating structure and hardness after annealing at temperatures up to 1173 K. Pure zirconia (m-ZrO2) coatings had low structure stability; the hardness reached a maximum value of 18±1 GPa after annealing at a temperature of 773-873K; however, at higher annealing temperatures the hardness decreased, reaching a minimum value of 12.3±0.6 GPa after annealing at 1173K. The hardness of the nanocomposite ZrO2/Al2O3 coating with various compositions increased with annealing temperature. The hardness of a coating with an alumina content of 17% reached a high value of 19.2±0.5 GPa after annealing at 1073-1173 K. Measurements of post annealing XRD analyses indicated that the stabilization of the coating structure with c-ZrO2/a-Al2O3 phases is the reason for the higher structure stability. From the analyses of phase stability and hardness before and after annealing, we conclude that adding alumina to the zirconia phase promotes the formation of nanocomposite c-ZrO2/a-Al2O3 coatings with a markedly higher stability than single-phase m-ZrO2.
Highlights:
1. ZrO2/Al2O3 nanocomposite coatings were deposited by co-sputtering from Zr and Al targets.
2. Adding alumina to the zirconia coating stabilized the cubic zirconia phase.
3. ZrO2-17% Al2O3 coatings had a grain size of 10-15 nm and a hardness of 16.1±0.5 GPa.
4. ZrO2/Al2O3 coatings maintained a high hardness after annealing at 1173K with a high value of 19 GPa for alumina content of 17%.
5. The ZrO2/Al2O3 nanocomposite coatings were crack-free after annealing at 1173K.
References
http://dx.doi.org/10.1016/j.surfcoat.2005.08.091
[2] Green DJ, Hannink RHJ, Swain MV. Transformation Toughening of Ceramics, CRC, Boca Raton FL 1989.
[3] Lange FF. Transformation toughening, Part 3: Experimental observations in the ZrO2-Y2O3 system. J Mater Sci 1982; 17: 240-6.
http://dx.doi.org/10.1007/BF00809059
[4] Lange FF. Transformation toughening, Part 4: Fabrication, fracture toughness and strength of AI2O3-ZrO2 composites. J Mater Sci 1982; 17: 247-54.
http://dx.doi.org/10.1007/BF00809060
[5] Musil J, Sklenka J, Cerstvy R, Suzuki T, Mori T, Takahashi M. The effect of addition of Al in ZrO2 thin film on its resistance to cracking. Surf Coat Technol 2012; 207: 355-60.
http://dx.doi.org/10.1016/j.surfcoat.2012.07.017
[6] Jerebtsov DA, Mikhailov GG, Sverdina SV. pahse diagram of the system: ZrO2-Al2O3. Ceram Int 2000; 26: 821-3.
http://dx.doi.org/10.1016/S0272-8842(00)00023-7
[7] Sheng SH, Zhang RF, Veprek S. Study of spinodal decomposition and formation of nc-Al2O3/ZrO2 nanocomposites by combined ab initio density functional theory and thermodynamic modeling, Acta Materialia 2011; 59: 3498-509.
http://dx.doi.org/10.1016/j.actamat.2011.02.023
[8] Barshilia HC, Deepthi B, Rajam KS. Stabilization of tetragonal and cubic phases of ZrO2 in pulsed sputter deposited ZrO2/Al2O3 and ZrO2/Y2O3 nanolayered thin films. J Appl Phys 2008; 104: 113532.
http://dx.doi.org/10.1063/1.3040720
[9] Teixeira V, Monteiro A, Duarte J, Portinha A. Deposition of composite and nanolaminate ceramic coatings by sputtering. Vacuum 2002; 67: 477-83.
http://dx.doi.org/10.1016/S0042-207X(02)00235-X
[10] Kim SK, Le VV, Boxman RL, Zhitomirsky VN, Lee JY. Cathodic arc plasma deposition of nano-multilayered Zr–O/Al–O thin films. Surf Coat Technol 2010; 204: 1697-701.
http://dx.doi.org/10.1016/j.surfcoat.2009.10.037
[11] Klostermann H, Bocher B, Fietzke F, Modes T, Zywitzki O. Nanocomposite oxide and nitride hard coatings produced by pulse magnetron sputtering. Surf Coat Technol 2005; 200: 760-4.
http://dx.doi.org/10.1016/j.surfcoat.2005.02.120
[12] Qadri SB, Gilmore CM, Quinn C, Skelton EF, Gossett CR. Stractural stability of ZrO2-Al2O3 thin films deposited by magnetron sputtering. J Vac Sci Technol 1989; A7: 1220-4.
http://dx.doi.org/10.1116/1.576258
[13] Trinh DH, Kubart T, Nyberg T, Ottosson M, Hultman L, Hogberg H. Direct current magnetron sputtering deposition of nanocomposite alumina—zirconia thin films. Thin Solid Films 2008; 516: 8352-8.
http://dx.doi.org/10.1016/j.tsf.2008.04.040
[14] Zukerman I, Zhitomirsky VN, Beit-Ya’akov G, Boxman RL, Raveh A, Kim SK. Vacuum arc deposition of Al2O3–ZrO2 coatings: arc behavior and coating characteristics. J Mater Sci 2010; 45: 6379–88.
http://dx.doi.org/10.1007/s10853-010-4734-7
[15] Aita CR, Scanlan CM, Gajdardziska-Josifovska M. Sputter deposited zircoina-alumina nanolaminate coatings. JOM 1994; 46: 40-2.
http://dx.doi.org/10.1007/BF03222607
[16] Andritschky M, Cunha I, Alpuim P. Thermal stability of zircoina/alumina thin coatings produced by magnetron sputtering. Surf Coat Technol 1997; 94–95: 144-8.
http://dx.doi.org/10.1016/S0257-8972(97)00492-1
[17] Musil J, Satava V, Zeman P, Cerstvy R. Protective Zr-containing SiO2 coatings resistant to thermal cycling in air up to 1400 °C. Surf Coat Technol 2009; 203: 1502-7.
http://dx.doi.org/10.1016/j.surfcoat.2008.11.026
[18] Williamson GK, Hall WH. X-ray line broadening from filed Al and W. Acta Metall 1953; 1: 22-31.
http://dx.doi.org/10.1016/0001-6160(53)90006-6
[19] Ohring M (2002) The Materials Science of Thin Films 2st Ed., Academic Press Inc., San Diego, pp. 547-588.
[20] Koski K, Holsa J, Juliet P. Properties of zirconium oxide thin films deposited by pulsed reactive magnetron sputtering. Surf Coat Technol 1999; 120–121: 303–12.
http://dx.doi.org/10.1016/S0257-8972(99)00501-0
[21] Rickerby DC, Burnett PJ. Correlation of process and system parameters with structure and physically vapor deposited hard coatings. Thin Solid Films 1988; 157: 195-222.
http://dx.doi.org/10.1016/0040-6090(88)90004-1
[22] Koski K, Holsa J, Juliet P. Deposition of aluminum oxide thin films by reactive magnetron sputtering. Thin Solid Films 1999; 339: 240–8.
http://dx.doi.org/10.1016/S0040-6090(98)01232-2
[23] Giannakopoulos AE, Larsson PL, Vestergaarf R. Analysis of Vickers indentation. Int J Solid Structures 1994; 31: 2679-708.
http://dx.doi.org/10.1016/0020-7683(94)90225-9
[24] Musil J. Flexible hard nanocomposite coatings. RSC Advansed 2015; 5:60482-95.
http://dx.doi.org/10.1039/C5RA09586G
[25] ASM Handbook, Vol. 20, Materials selection and design, 1997
[26] Watanabe H, Yamada N, Okaji M. Linear thermal expansion coefficient of silicon from 293 to 1000K. Int J Thermophys 2004; 25: 221-36.
http://dx.doi.org/10.1023/B:IJOT.0000022336.83719.43
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