Studies on crystallization of electroless NiP deposits

doi:10.1016/0924-0136(96)85110-7

Journal of Materials Processing Technology

Volume 56, Issues 1–4, January 1996, Pages 511-520

https://doi.org/10.1016/0924-0136(96)85110-7 Get rights and content

Abstract

Electroless Nickel-Phosphorus deposits with phosphorus content of 4.35, 5.45, 6.80, 8.10 and 9.12 Wt.% P were made, on mild steel substrates. The deposits were annealed at 60, 100, 200, 300, 330, 360, 400 and 600°C for 2 hours. The crystallization process of these deposits was studied using X-ray line profile analysis, differential scanning calorimetry and microhardness. The X-ray diffraction pattern of all the deposits indicated the presence of crystalline and amorphous phases coexisting in the as deposited condition. The lattice disorder in the crystalline phase increased with increasing phosphorus content. Profile refinement techniques have been used to separate the crystalline nickel (111) reflection from the amorphous profile. The separated (111) and (222) profiles of nickel were used for crystallite size and microstrain analysis. The crystallite size of nickel was found to vary from 50Å in the as deposited condition to about 600Å in the fully annealed state (400°C). The crystallite size increased sharply above 300°C, indicating the onset of precipitation. The microhardness values showed typical precipitation hardening type of behavior, increasing from an initial value of about 450 VHN in the as deposited state to the peak hardness of about 825 to 950 VHN, corresponding to a temperature range of 360 to 400°C. Differential scanning calorimetry of these deposits, indicated only one major reaction between 325 to 375°C. Ni₃P has been identified as the final stable precipitate at 600°C.

References (21)

S.L. Chow et al.
J. Elect. Chem. Soc.
(1972)
K. Sugita et al.
J. Elect. Chem. Soc.
(1984)
A.W. Goldenstein et al.
J. Elect. Chem. Soc.
(1957)
Su Hoon Park et al.
J. Mat. Sci.
(1988)
S.V.S. Tyagi et al.
Bull. Mater. Sci.
(June 1986)
Ramesh Chandra Agarwala et al.
Z. fur Metallkunde
(July 1988)
E. Vafaei-Makhsoos et al.
Metall. Trans.
(1978)
Sang-Heon Hur, Jae-Han Jeong and Dong Nyung Lee, J. Mat. Sci, Vol.25, p....
Ramesh Chandra Agarwala et al.
Z. fur Metallkunde
(Aug. 1989)
Ramesh Chandra Agarwala et al.
Z. fur Metallkunde
(March 1992)

There are more references available in the full text version of this article.

Cited by (147)

Mechanical and tribological characterization of deep eutectic solvent assisted electroless Ni–P-hBN coating
2023, Ceramics International
Compositions and processing methods govern various characteristic features of electroless coatings. Electroless nickel–phosphorus (Ni–P) composite coatings containing varying amounts of hBN, deposited using a deep eutectic solvent (DES), achieved better tribological properties as compared to the coating of the same composition deposited in the conventional method. This study also attempted to determine the specific concentration of hBN particles in the electroless bath that deposits Ni–P-hBN coating with a superior combination of mechanical and tribological characteristics. Stronger bond formations of hBN particles in the Ni–P alloy matrix ensured by hBN's metallic behavior potentially influence its tribological properties.
Role of surfactants on particle deposition, wear, and corrosion behavior of TaC particle incorporated electroless nickel-phosphorus coating
2022, Progress in Natural Science: Materials International
Citation Excerpt :
The coating's microstructural properties were investigated using XRD, HRTEM, and EDS analysis. ENP coating in its as-coated state has either an amorphous phase or a composition of nanocrystalline Ni and an amorphous matrix phase [19,20]. The XRD data presented in Fig. 3a shows that the Ni–P and Ni–P–TaC coating systems consisted of a broad peak ranging from 40 to 50° and centered around 44.5° in the 2 theta axis, indicating a mixture of Ni nanocrystalline and amorphous NiP phase of the coating matrix.
The coatings prepared by incorporating submicron-sized TaC particles while depositing Ni and P atoms on the steel substrate via electroless method showed mixed results of surface finishing, microstructural properties, mechanical, tribological, and corrosion behavior with the addition of various surfactants during the coating process. The surfactant sodium dodecyl sulfate (SDS) enhanced the microhardness when added during the coating process of Ni–P–TaC composite, whereas the cetyltrimethyl ammonium bromide (CTAB) lowered the microhardness as compared to the surfactant-free coating. Moreover, the TaC particle incorporation was hindered by the surfactants CTAB and Triton X-100. An excellent wear resistance behavior has been observed in the surfactant-free Ni–P–TaC coating in comparison to particle-free Ni–P coating. The Ni–P–TaC coatings showed the dependency of wear behavior on the material properties of the counter sliding surface although this dependency has not been observed in Ni–P coatings. The wear damage in Ni–P coating is immense irrespective of the properties of counter-sliding materials. Various surfactant-used Ni–P–TaC coating surfaces deteriorated much more due to corrosion than surfactant-free Ni–P–TaC coating. Among the various surfactants, the CTAB used Ni–P–TaC coating showed weak corrosion resistance.
Micro-abrasive wear resistance of heat-treated electroless nickel‑phosphorus coatings deposited on copper‑beryllium alloy C17200
2022, Surface and Coatings Technology
Copper‑beryllium alloys are widely used to manufacture thermoplastics injection molds due to their high thermal conductivity. Even though these alloys admit precipitation hardening at temperatures between 250 and 400 °C, they still call for surface coatings to enhance their abrasion resistance. However, application of these coatings can generate over-aging under specific deposition temperature ranges. This phenomenon causes a loss of substrate mechanical properties, making some industrial applications unfeasible, for example: construction of core pins with high slenderness ratio, and cores and cavities injection mold with narrow closure regions. This work proposes a solution to increase abrasive wear resistance of copper‑beryllium alloy C17200 through an electroless nickel‑phosphorus (NiP) coating. Temperature used in heat treatment of the coating was lower than substrate aging temperature. In this work, the heat treatment was carried out at 200 °C for 24 h. Hardness of coating and substrate was evaluated by measuring the cross-sectional microhardness profile after heat treatment. Microstructure, chemical composition, and crystallinity of coating and substrate were characterized using scanning electron microscopy (SEM), glow discharge optical emission spectroscopy (GD-OES), and X-ray diffraction (XRD), respectively. Wear behavior of coating-substrate systems was evaluated by micro-abrasive wear tests optical profilometry and SEM. NiP coating combined with heat treatment increased the surface hardness from 340 HV for uncoated alloy to an average of 997 HV for coated and heat treated alloy while maintaining substrate hardness. The application of this coating reduced the wear coefficient in the order of 3.03 × 10⁻⁶ to 2.04 × 10⁻⁶ (mm³ N⁻¹ m⁻¹). All the conditions analyzed, showed a mixed micro-abrasive wear mechanism with rolling and grooving wear characteristics.
Electrodeposited metallic glasses with superlative wear resistance
2021, Materials Science and Engineering: A
The electrodeposition route to obtain amorphous alloys offers a facile, low-cost, and versatile alternative to conventional melt quenching. However, there are significant knowledge gaps in tribological properties and wear mechanisms for electrodeposited metallic glasses (EMGs). Here, the wear behavior and the scratch response of a model binary amorphous alloy system were investigated. Electrodeposited Ni–P metallic glasses were systematically studied as a function of composition, with amorphous alloy formation over the narrow range of 10 at% to 20 at% phosphorus. The electrodeposited metallic glasses showed hardness values in the range of 6.6–7.4 GPa, modulus in the range of 155–163 GPa, and friction coefficient around 0.50. Among the studied alloys, electrodeposited Ni₈₀P₂₀ showed the lowest wear rate, which was two orders of magnitude lower than electrodeposited pure Ni. The wear mechanism was determined to be extensive plastic deformation along with mild ploughing, micro tears, and formation of discontinuous lubricious oxide patches. Scratch tests showed an increase in critical load for damage initiation with the increase in phosphorus content among the amorphous alloys following the trend: Ni₈₀P₂₀ > Ni₈₅P₁₅ > Ni₉₀P₁₀. The overall wear rate for the electrodeposited metallic glasses was found to be lower than most reported bulk metallic glasses (BMGs). This represents a fundamental study on structure-property correlations in electrodeposited metallic glasses and demonstrates the versatility of electrodeposition in tuning the surface properties of amorphous alloys.
Annealed high-phosphorus electroless Ni–P coatings for producing molds for precision glass molding
2021, Materials Chemistry and Physics
An annealed high-phosphorus electroless Ni–P coating was developed as the mold material for precision glass molding. The coating with a phosphorus content of 11.6 wt% was prepared on heat-resistant stainless steel via an intermittent ultrasonic-assisted electroless plating method. The effects of annealing temperature and heating rate on phase transformation, grain size variation, and mechanical properties were investigated. An annealing temperature of 600 °C with a heating rate of 5 °C/min was determined to be the optimal choice for heat treatment. Microgrooves were machined on the coating surface. After heat treatment, the increased hardness and modulus helped the microgrooves on the coating resist thermal deformation during the PGM process. The PV value decreased from 0.58 to 0.32 μm, and the surface roughness decreased from Sa 104.5 to Sa 62.6 nm. The mold produced by heat-treated coating was beneficial for improving the forming accuracy of precision glass molding.
Electroless NiP coatings over API X70 steel: Effect of composition on the H-permeation and corrosion resistance
2021, Surface and Coatings Technology
The present work discusses the effect of hypo-eutectic, near-eutectic and hyper-eutectic electroless NiP coatings, laid over an API (American Petroleum Institute) X70 grade steel, on their resistance to H-permeation as well as corrosion against chloride attack. The H-permeation was investigated using a Devanathan-Stachursky electrochemical permeation cell. All the three NiP coatings displayed excellent H-barrier property along with good corrosion resistance in comparison to the base metal and even electrodeposited Ni coating. Detailed microstructural investigation using Scanning Electron Microscopy, Transmission Electron Microscopy, X-Ray Diffraction, X-ray Photoelectron Spectroscopy and Differential Scanning Calorimetry revealed the coatings to be primarily amorphous with the presence of a few nano-crystalline areas. The corrosion resistance of the coated steel was also investigated using both dynamic polarization test in freely aerated 3.5 wt% NaCl solution and salt fog exposure test in 5 wt% NaCl solution. Further, the corrosion products formed on these coated surfaces after prolonged salt-fog exposure were characterized with the help of Raman Spectroscopy and subsequently, correlated with their corrosion behavior. The near-eutectic NiP coating displayed higher resistance to corrosion as compared to the hypo- and hyper-eutectic NiP coatings due to the formation of amorphous Fe(OH)₃ and higher α/γ FeOOH ratio in the rust.

View all citing articles on Scopus

View full text

Studies on crystallization of electroless NiP deposits

Abstract

J. Elect. Chem. Soc.

J. Elect. Chem. Soc.

J. Elect. Chem. Soc.

J. Mat. Sci.

Bull. Mater. Sci.

Z. fur Metallkunde

Metall. Trans.

Z. fur Metallkunde

Z. fur Metallkunde