Sage Journals: Discover world-class research

Abstract

Ni–W–P coatings with different structures were prepared by electroless deposition. The correlation between the coating structure before and after annealing with hardness and corrosion resistance has been examined by microhardness measurement, potentiodynamic polarisation and corrosion weight loss tests, and by quantitative X-ray diffraction technology and scanning electron microscopy observation of the corrosion morphology. The results indicate that incorporation of tungsten (4–5 wt-%) in Ni–P deposits does not change the amorphous structure of the Ni–11·3 P (wt-%) coating or the mixed structure of the Ni–6·8 P (wt-%) coating, but it changes the Ni–5·1 W–9·3 P (wt-%) coating into a critical amorphous structure. The coating with a critical amorphous structure develops a higher degree of crystallisation, larger crystal size and smaller number of Ni₃P crystallites after annealing at >300°C. It also exhibits the highest peak hardness and the poorest corrosion resistance after annealing at 400°C compared with the other two structural coatings (e.g. amorphous and mixed structures).

Keywords

Electroless Structure Microstrain Hardness Corrosion

Get full access to this article

View all access options for this article.

References

Palaniappa

and Seshadri

: ‘Hardness and structural correlation for electroless Ni alloy deposits’, J. Mater. Sci., 2007, 42, 6600–6606.

Tien

and Duh

: ‘Thermal reliability of electroless Ni–P–W coating during the aging treatment’, Thin Solid Films, 2004, 469–470, 268–273.

Liao

, Zhang

and Dryfe

: ‘A study of corrosion performance of electroless Ni–P and Ni–W–P coatings on AZ91D magnesium alloy’, Materialwiss. Werkstofftech., 2011, 42, (9), 833–837.

Palaniappa

and Seshadri

: ‘Friction and wear behavior of electroless Ni–P and Ni–W–P alloy coatings’, Wear, 2008, 265, (5–6), 735–740.

Balaraju

and Rajam

: ‘Electroless deposition of Ni–Cu–P, Ni–W–P and Ni–W–Cu–P alloys’, Surf. Coat. Technol., 2005, 195, (2–3), 154–161.

Balaraju

, Manikandanath

KalavatiNT

and William Grips

: ‘Phase transformation behavior of nanocrystalline Ni–W–P alloys containing various W and P contents’, Surf. Coat. Technol., 2012, 206, (10), 2682–2689.

Ranganatha

and Venkatesha

: ‘Studies on the preparation and properties of electroless Ni–W–P alloy coatings and its nano-MoS₂ composite’, Phys. Scr., 2012, 85, 035601.

Liu

, Guo

, Liu

, Thompson

and Liu

: ‘The effect of processing gas on corrosion performance of electroless Ni–W–P coatings treated by laser’, Surf. Coat. Technol., 2012, 206, (15), 3350–3359.

Jeong

, Erb

, Aust

and Palumbo

: ‘The relationship between hardness and abrasive wear resistance of electrodeposited nanocrystalline Ni–P coatings’, Scr. Mater., 2003, 48, (8), 1067–1072.

10.

Liu

, Guo

, Viejo

and Liu

: ‘Comparison of microstructure and residual stress characteristics of electroless Ni–W–P coatings annealed with a laser and a furnace’, Surf. Coat. Technol., 2012, 206, (8–9), 2380–2387.

11.

Allen

and Vander-Sande

: ‘The structure of electroless Ni–P films as a function of composition’, Scr. Metall., 1982, 16, (10), 1161–1164.

12.

Keong

, Sha

and Malinov

: ‘Crystallisation kinetics and phase transformation behaviour of electroless nickel–phosphorus deposits with high phosphorus content’, J. Alloys Compd, 2002, 334, (1–2), 192–199.

13.

, Luo

and Li

: ‘A transmission electron microscopy study on the crystallization of amorphous Ni–P electroless deposited coatings’, Thin Solid Films, 1988, 166, 273–280.

14.

Keong

and Sha

: ‘Crystallisation and phase transformation behaviour of electroless nickel–phosphorus deposits and their engineering properties’, Surf. Eng., 2002, 18, (5), 329–343.

15.

Martyak

and Drake

: ‘Peak–profile analysis of electroless nickel coatings’, J. Alloys Compd., 2001, 312, (1–2), 30–40.

16.

Balaraju

, Kalavati and Rajam

: ‘Surface morphology and structure of electroless ternary NiWP deposits with various W and P contents’, J. Alloys Compd, 2009, 486, (1–2), 468–473.

17.

Lin

and Hei

: ‘The structures of electrodeposited alloy of nickel–phosphorous systems’, Acta Phys. Chim. Sin., 1984, 33, (3), 302–308.

18.

Wang

, Guo

, Yu

, Sun

and Li

: ‘Microstructure and crystallisation process of electrode posited amorphous Ni–P coatings’, Trans. Mater. Heat Treat., 2009, 30, (1), 145–148.

19.

Marshall

, Lewis

and Bodds

: ‘Electroless deposition of Ni–P alloys with and without the use of superimposed pulsed current’, Surf. Coat. Technol., 1992, 53, (3), 223–230.

20.

, Qian

, Wang

and Liu

: ‘Effects of heat–treat temperature on microstructure of electro–brush plating Ni–P coatings’, Acta Metall. Sinica, 2010, 46, (7), 867–872.

21.

Yan

, Ying

and Ma

: ‘Improved microhardness and wear resistance of the as-deposited electroless Ni–P coating’, Surf. Coat. Technol., 2008, 202, (24), 5909–5913.

22.

Yuan

, Sun

, Yu

and Meng

: ‘Structure and mechanical properties of Ni–P electrodeposited coatings’, Appl. Surf. Sci., 2009, 255, (6), 3613–3617.

23.

Wang

, Chen

and Chen

: ‘Study on post–treatments for electroless Ni–P coating’, Surf. Eng., 2011, 27, (1), 57–60.

Correlation between structure and properties of annealed electroless Ni–W–P coatings

Abstract

Keywords

Get full access to this article

References