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Mittwoch, 15 September 2021 11:59

Black Electrochemical Coatings for Aerospace and Allied Applications – Part 4 – Black Chrome Plating

von
Geschätzte Lesezeit: 15 - 29 Minuten

Chromium is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. While chromium metal and Cr(III) ions are not considered toxic, hexavalent chromium, Cr(VI), is both toxic and carcinogenic. 85 % of the available chromium is used in metal alloys. The remainder is used in the chemical, refractory, and foundry industries. Chromium compounds are used in leather products, dyes, paints, cement, mortar and are anti-corrosives. Chromium salts (chromates) are allergic to some people. Chrome ulcers are often found in workers that have been exposed to strong chromate solutions in electroplating, tanning and chrome-producing manufacturers [1, 2]

Deposit growth, structural characterization and properties of electrodeposited chrome on substrates like copper, steel and aluminium alloys are well studied for several decades [3–51]. Black chrome plating provides a good wear resistance, corrosion protection and high durability. It has been widely used in automobiles, photography, solar energy collectors and optical instruments. The appearance of the black chrome finish depends on the nature of the substrate and the surface treatment adopted prior to electroplating. The finish can be a lustrous, semi-lustrous or a matte. The finish may be waxed or oiled to improve the final appearance. The general specifications for black chrome plating are given in MIL-DTL-14538.

The initial patent related to electroplating of black chromium was granted date back in 1952. Gilbert and Buhman [3] developed a process utilizing aqueous chromic anhydride and acetic acid to achieve a dark gray to black deposit on rifle components, artillery parts and military equipment at the Rock Island Arsenal. Owing to its commercial importance, the process has received an immense interest among researchers during seventies and eighties [7–27].

Highly polished black chrome is employed as a decorative finish on the visible parts of cars and motorcycles, as well as for household fixtures such as faucets. In contrast, matte finish black chrome plating is used inside telescopes and microscopes, and other areas where light reflection would interfere with the operation of the device. Solar selective black chrome coating is one of the well-received solar selective coatings in solar collector systems for the efficient conversion of solar energy into thermal energy because of its thermal stability up to ~ 400 °C [26, 27, 31].

Black chrome electroplates are obtained by replacing the sulphate ion in conventional chrome plating baths by acetate, fluoride, silicofluoride, borate, nitrate or sulphamate ions. In the fluoride or mixed catalyst plating baths, a harder, more corrosion and wear-resistance deposit is obtained with a higher plating efficiency. The fluoride is often added as the SiF62- ion to provide better substrate activation for plating on bright nickel. Some typical bath formulations and operating conditions for black chrome plating are given in Table 4.1 [4, 5, 28, 33].

Tab. 4.1: Typical bath formulations and operating conditions for decorative black chrome plating

Bath constituents and operating conditions

Bath 1

Bath 2

Bath 3

Bath 4

Bath 5

Chromic acid, g/L

250–400

250

250

340

250

Fluosilicic acid, g/L

 

0.5

 

0.34

0.25

Acetic acid, g/L

5–10

 

216

   

Barium acetate, g/L

   

7.6

11

 

Temperature, °C

30

20–25

38

21

32

Current density, A/dm2

80–100

25–30

4–9

20

15–45

The black chrome deposits have a high degree of micro-porosity due to the evolution of hydrogen [39], which gives the coatings the ability to absorb and retain oil and paint films which makes them useful for machine tools. An undercoat of nickel is preferred before black chrome deposition as a barrier coating to improve corrosion resistance [13, 34, 35]. Nickel under coat also helps in lowering the thermal emissivity and enhancing the thermal resistance of black chrome coatings for solar collector applications. Measurements of the spectral reflectance properties of a commercially prepared black chrome and black nickel on steel as a solar selective coating for NASA applications have been reported by McDonald [36].

Black chromium electrodeposition on electrodes modified with formic acid and the corrosion resistance performance of the coating on copper was studied by Surviliene et al. [29]. The current efficiency of black chromium increases on the modified electrode only at the beginning of electrodeposition until the thickness of the deposit reaches 1 μm. The adsorption layer of formic acid (HCOOH) has an effect on the formation of the near-electrode film, this being typical for the chromium deposition process and on the reaction Cr(VI)→Cr(III) as well. The surface modification with an adsorbed layer of formic acid significantly improves the corrosion resistance of black chromium coating. This is primarily due to the formation of a thin, compact, amorphous layer (about 1 μm) under the influence of HCOOH.

Aguilar et al. [30] electrodeposited thin films of black and white chromium on stainless steel substrates. The authors have characterized both the films by XRD, XPS, SEM and spectral reflectance measurements. It was concluded that the black chromium has a lamellar morphology that leads to a strong dispersion level while the white film has a flat morphology. The black chromium film has good selective optical properties that remain practically constant even when heat treated to a high temperature of 400 °C.

Quintana and Sebastian [37] have investigated the influence of various substrate pre-treatments such as mechanical polishing, chemical etching and electropolishing prior to the electrochemical deposition of a black chrome on a copper substrate. XRD and SEM analysis showed that electropolishing of the substrates prior to black chrome deposition results in black chrome coatings with more metallic chromium, while mechanical polishing favours the formation of more oxides of chromium. The films formed after mechanical polishing followed by electropolishing exhibited good solar selective characteristics, whereas chemical etching of the substrates resulted with poor solar selectivity.

A process of black chrome plating on aluminium alloy 6061 with different undercoats was described by Shashikala et al. [38]. The process involves the following sequence:

(a) Ultrasonic solvent degreasing in trichloroethylene for 5 to 10 minutes.

(b) Alkaline cleaning in a solution containing sodium carbonate 20 to 25 g/L, sodium meta silicate 8 to 12 g/L and tri sodium orthophosphate 8 to 12 g/L, at 65 ± 5 °C for 3 to 4 minutes followed by water rinsing.

(c) Chemical polishing [52] in a solution containing orthophosphoric acid 80 % (v/v), nitric acid 3.5 % (v/v), and copper 0.01 % (wt) for 20 to 25 seconds at 90 °C followed by hot water rinse.

(d) De-smutting in an acid solution containing 10 ml/L sulphuric acid, 12 m/L hydrofluoric acid and 25 ml/L nitric acid for 2 to 3 minutes at room temperature followed by water rinsing.

(e) Alloy zincating by immersion the job at room temperature with agitation for 45 seconds in a solution containing nickel sulphate, NiSO4·7H2O, 30 g/L; zinc sulphate, ZnSO4·7H2O, 40 g/L; sodium hydroxide, NaOH, 106 g/L; potassium cyanide, KCN, 10 g/L; potassium bitartrate, KC4H5O6, 40 g/L; copper sulphate, CuSO4·5H2O, 5 g/L and ferric chloride, FeCI3, 2 g/L at room temperature (25 ± 2 °C) [53]. Followed by water rinsing.

(f) Stripping of the relatively loose alloy zincating layer by immersion in 50 % (v/v) nitric acid solution at room temperature for 1 to 2 minutes. Followed by water rinsing.

(g) Re-zincating by repeating step 5 for 1 minute to provide uniform and compact fine grains of zinc alloy layer. Water rinsing.

(h) Alloy zincated specimens were given different under coatings prior to black chrome using following solutions:

Non-cyanide copper plating at 25 ± 2 °C [54]
Cyanide copper plating at 50 ± 2 °C [55]
Nickel plating in Watts bath at 45 ± 2 °C [56]
Electroless nickel plating at 90 ± 2 °C [53]
The undercoated specimens were followed by thorough water rinsing.

(i) Black chrome plating was carried out in a solution containing 400 g/L chromic acid, 15 g/L barium acetate and 180 ml/L acetic acid at 30 °C using current density at 40 to 46 A/dm2 (40 A/dm2 for cyanide and non-cyanide copper undercoat, 42.5 A/dm2 for electroless nickel and 46 A/dm2 for electro-nickel undercoat) for 1 minute. Followed by water rinsing.

(j) Heat treatment at 200 °C in a hot air circulation oven for 1 hour.

When aluminium and its alloys are exposed to the atmosphere, a passive oxide layer is formed which prevents the formation of further coating. Such a naturally formed oxide layer can be removed by zincating, which also protects the formation of further natural passive oxide layer on aluminium. The overall process can be represented by the following reactions:

The dissolution of aluminium:

Al + 3 OH → AI(OH)3 + 3 e

AI(OH)3 → [H2AIO3] + H+

This is followed by the deposition of zinc and accompanied by the evolution of hydrogen:

[Zn(OH)4]2– + 2 e → Zn° + 4 OH

2 H+ + 2 e → H2

In the black chromium plating solution acetate ions act as catalyst. The possible reactions of the process are given below [20, 21]:

Electrolytic reactions:

CrO3 + H2O → H2CrO4 → [HCrO4] + H+

2 [HCrO4] → [Cr2O7]2- + H2O

[Cr2O7]2– + 14 H+ + 6 e → 2 Cr3+ + 7 H2O

Cathodic reactions:

[Cr2O7]2– + 6 H+ + 6 e → CrO3 + 2 H2O + 2 OH-

[Cr2O7]2– + 14 H+ + 12 e → 2 Cr° + 7 H2O

2 H+ + 2 e → H2 ↑ (Side reaction)

Anodic reaction:

2 Cr3+ + 3 O2 → 2CrO3 + 6 e

The XRD pattern shows the presence of predominantly bcc chromium and some Cr2O3 (hexagonal). Surface morphology of black chrome was found to influence the solar absorptance of the coating. The enhancement in solar absorptance occurs either by an array of fine particles causing intrinsic adsorption or by reducing the front surface reflections from an absorber surface. Black chrome coatings with all three above undercoats showed spherical particulate morphology. The particle size was, however, greater in the case of black chrome coatings on electroplated nickel and non-cyanide copper substrate as compared to the coatings on electroless nickel and cyanide copper.

A good black coating with good solar selectivity was obtained with a coating thickness of ~ 5 µm. The polarization studies (Icorr values) of black chrome coating with different undercoat were found in the following order: Non-cyanide Cu > Cyanide Cu > Electroplated Ni > Electroless Ni. This clearly indicates the superior corrosion resistance of the electroless nickel undercoating. Thermal stability of the coatings was established up to 250 °C. The α/ε ratio of different coatings was found in the following order: cyanide Cu (4.0) > electroplated Ni (6.0) > non-cyanide Cu (8.3) > electroless Ni (8.45). The process with electroless nickel undercoating provided a high solar absorptance (0.93) and low thermal emittance (0.11) coating with superior corrosion resistance, which is extremely suitable for solar selective applications.

Black chrome coatings were electrodeposited on nickel coated copper substrates by using a Chromonyx type electrolyte by Lee [39]. The substrates were processed for plating with the following sequence:

(a) Surface cleaning with 1500–2000 grit sandpapers, followed by polishing with Buehler 0.05 µm Al2O3 paste.

(b) Cathodic cleaning for 2 minutes in NaOH solution.

(c) Surface activation by immersing in 10 % solution of H2SO4.

(d) Electrodeposition of a thick layer of nickel by standard Watts nickel bath to achieve high infrared reflectance.

(e) Black chrome films electroplating with Chromonyx (Harshaw Chemical Co) electrolyte [40] composed of chromic acid, ~340 g/L, Chromonyx MR, ~26 g/L, Chromonyx AA, ~270 ml/L and barium carbonate, ~7.5 g/L; at a current density of 26–27 A/dm2 for 1.5–2.0 minutes. A Pb-Sn alloy (95–5 %) was used as the anode. The area ratio of the anode to the cathode was kept 2:1 and the distance between the anode and the cathode was maintained at 5 cm.

The film surface exhibited a rms roughness of 55.83 nm. Analysis of the Auger electron spectrometry (AES) and the glow discharge spectrometry (GDS) depth profiles indicated that the black chrome coating is formed due to oxidation of metallic chrome crystallites within the coating to chromium oxide. The black chrome coatings were identified as amorphous. The thermal stability test showed the stability of the coatings up to 350 °C with a solar absorptance value of 0.80 and thermal emittance value of 0.01. Jafari and Rozati [41] deposited black chrome films on bright nickel-plated brass substrates with two different chemical baths and characterized the deposits by SEM, XRD and EDX. The spectral reflectance was also measured in the UV-Vis-NIR and IR regions. The following process of sequence was adopted:

(a) Mechanical polishing with a grinding paper no. 2000.

(b) Cleaning with a hot commercial alkaline cleaner.

(c) Activation in 10 vol % H2SO4.

(d) Bright nickel deposition in nickel sulphate, nickel chloride and boric acid bath, at 50–60 °C, 0.5A/dm2, for 5 minutes.

(e) Black chrome plating with two chemical baths: (i) acetate bath consisting of chromic acid, acetic acid and barium acetate, operating at 50 °C, 3 A/dm2, for 3 minutes, (ii) fluoride-catalysed bath containing chromic acid, fluorosilicic acid and barium carbonate, and operating at 25 °C, 6 A/dm2, for 2 minutes.

The coatings prepared with acetate baths were denser with nano size grains and those with fluoride-catalysed baths were more porous, with micro sized grains. The film formed with fluoride-catalysed baths also showed the better optical properties (solar absorptance 98.5 %) than the acetate bath (90 %).

A solar selective black chromium coating on SS 304 with a mean absorption of 94.6 % and maximum absorption of 96 % in the UV-Vis-NIR range (220 nm to 1400 nm) was reported by Medeiros et al. [42] for an average film thickness of 3.63 µm with a surface roughness (Ra) of 0.05 µm. An electrolyte bath composed of 274 g/L of chromium trioxide and 0.854 g/L of hexafluorosilicic acid, Pb-Sb alloy (95–5 %) anode, anode to cathode distance 5 cm, operating at 24–30 °C, 5 V, for 5 minutes provided the optimum results.

4.1 Black Chrome from Trivalent Chromium Salts

Hexavalent chromium compounds have high oxidizing power and are genotoxic carcinogens [57]. Cr(VI) compounds are harmful to the eyes, skin, and respiratory system and may cause lung cancer when inhaled. Hence, their use is heavily regulated [58]. There are constant efforts to replace hexavalent chromium with eco-friendly chemicals including the trivalent chromium which is relatively environmentally benign though has low conductivity [43]. The first patent for trivalent chromium plating dates back to the seventies, Gyllenspetz and Renton [44] of Albright and Wilson were one of the early pioneers for the development of trivalent chromium electroplating baths. The trivalent black chromium processes utilize a chromium (iii) chloride or chromium (iii) sulphate salt as the main electrolyte component, instead of chromium trioxide of hexavalent black chromium. The trivalent baths operate at a pH range of 2-4 while the hexavalent black chromium operates at a pH of less than 1. Comparison of trivalent black chromium and hexavalent black chromium processes is presented in Table 4.2.

Electrolyte and deposition conditions

Trivalent black chromium

Hexavalent black chromium

Electrolyte metal component

Chromium (III) chloride

Chromium (III) sulphate

Chromium trioxide

pH

2–3

3.2–3.8

< 1

Temperature, °C

21–50

50–60

32–60

Current density, A/dm2

7–12

12–14

17.5–30.0

Anode material

Carbon

Precious metal coated titanium

Lead-Tin (7 %)

Anode-Cathode area ratio

2:1

2:1

1:1 to 3:1

Agitation

Mild air

Mild air

Optional

Voltage, V

Up to 12

Up to 12

4–12

Maximum deposit thickness, µm

> 1

0.3

> 5

Deposition rate, µm/minute

0.15–0.25

0.02–0.03

0.10–0.18

Thin films of black chromium on the steel substrates have been prepared by electrodeposition from trivalent chromium salt by Abdel Hamid [46] with an electrolyte containing, CrCl3.6H2O: 266 g/L, CoCl2.6H2O: 15 g/L, H2SiF6: 8 g/L, NaH2PO4: 4 g/L, NaF: 21 g/L, operating at 25 °C, at a current density of ~ 30 A/dm2 for 1 minute. Cobalt was added to improve efficiency of the electroplating bath and optical properties of black chromium coating. A 1-µm thick film was deposited. The influence of fluorosilicic acid concentrations on the trivalent chromium electrodeposition was studied by the potentiodynamic technique. SEM analysis revealed that the black chromium has nano lamellar morphology that leads to a strong dispersion level. The X-ray diffraction (XRD) and X-Ray photoelectron spectroscopy (XPS), results showed that external layers of the films are made of mainly chromium, chromium oxide and cobalt oxide. The black chromium-cobalt alloy film showed good solar absorptance of 0.97 % that remain practically constant even after heat treatment at 400 °C for 24 hours.

The studies related on the microstructures and physical properties of black chrome coatings, were carried out by Moise et al. [47]. The chromium oxide films were deposited on nickel coated copper substrates from a modified tetrachromate bath [8], consisting of 400 g/L of chromic acid, 60 g/L of sodium hydroxide, 7.5 g/L of barium carbonate for sulphate removal, 2.5 g/L of sucrose to produce trivalent chrome, and 0.5 g/L fluosilicic acid; temperature: 25 °C; current density: 20 A/dm2; time: 3 minutes. Lead was used as the counter electrode. Alternative experiments were conductive with direct trivalent chromium salt, e.g., Cr2(SO4)3: 1.5 g/L. A marked difference in the particle morphology has been observed by modifying the source of the trivalent chromium ions from the addition of sucrose to the solution containing hexavalent chromium ions to directly using a trivalent chromium salt, chromium sulphate. The coating morphology altered from polyhedral irregular shape particles to a denser elongated or spherical shape defined particles. A mean value of 0.97 of absorption coefficient was reported.

Bayati and his co-workers [48] finalised the following process conditions for trivalent black chromium plating on 1 mm thick copper plates samples for solar thermal collectors’ applications.

(a) Mechanical polishing with grinding papers no. 600.

(b) Electropolishing in 1.2 M phosphoric acid solution at 30 °C, where a lead plate was used as cathode. First the samples were electropolished at a current density of 35 A/dm2 for 30 seconds and after that the current density was decreased to 9 A/dm2 for 3 minutes.

(c) Black chrome plating in final designed bath containing Cr3+ ion (chromium sulphate): 1M, Co2+ ion (cobalt chloride): 15 g/L, sodium hypophosphite: 0.75 M, sodium dihydrogen phosphate: 4 g/L, sodium fluoride: 0.5 M; temperature: 30 °C; pH: natural 0.5–1.0; current density: 35 A/dm2; 1 minute plating was selected which produced a coating of thickness ~ 2 µm.

(d) Heat treatment at 300 °C for 200 hours in an air atmosphere, followed by air cooling.

Nickel plating before black chromium coating was recommended to increase the thermal resistance. SEM and XRD techniques were employed to characterize the surface microstructure and chemical composition. An absorption coefficient of 0.96 with optimum conditions was reported.

Nunes et al. [49] electrochemically deposited solar selective black chrome on SS 304. The following process was followed:

(a) Mechanical polishing with a grinding paper of 240–600 mesh and polishing paste of 9 µm and 3 µm, to obtain smooth surfaces.

(b) alkaline degreasing in of 10 % NaOH solution for 60 seconds.

(c) Acid activation in 10 % HCl solution for 30 seconds.

(d) Black chrome plating from a chemical bath composed of CrCl3 250 g/L, CoCl2 14.1 g/L, H2SiF6 7.50 g/L, NaH2PO4 3.80 g/L, NaF 19.7 g/L; 40 °C, 2 A, 4 V for 90 seconds.

After deposition, the samples were heat treated at 600 °C for 2 hours for oxidation. The XRD measurements indicated that the structure of the black chromium film mainly consists of crystalline metallic chromium and chromium oxide. The heat treatment was found to enhance the absorptance because of an increase in phase of chromium oxide at 2θ = 35.5º and 2θ = 64.0º. A coating thickness of 18-20 µm resulted in solar absorptance of more than 90.0 % in UV/Vis/NIR regions.

Black chromium on steel and copper plates was electrodeposited from a trivalent chromium bath using a ZnO additive as a second main component by Survilienė and his co-workers [50]. The following bath was used: CrCl3·6H2O: 250 g/L, glycine NH2CH2COOH: 18.75 g/L, H3BO3: 30.0 g/L, NaCl: 60.0 g/L, NaNO3: 3.0 g/L, ZnO: 5.0 g/L; pH = 1.2, temperature: 18–-20 °C; current density: 20–40 A/dm2. The coatings were characterized by XRD and SEM. The XRD data suggested that the phase structure of black chromium may be defined as a zinc solid solution in chromium or a chromium solid solution in zinc depending on the chromium / zinc ratio in the deposit. The role of substrate finish was evaluated through the corrosion resistance and reflectance of black chromium. The samples plated with bright nickel prior to black chromium deposition have shown the higher corrosion resistance. The absorption coefficient of black chromium was found to be over 0.99 for the samples obtained without the Ni undercoat and slightly below 0.99 for those obtained with the use of Ni undercoat. However, the use of nickel undercoat before black chromium plating is recommended because it remarkably improves the corrosion resistance of samples.

Usmani et al. [51] investigated the thermal stability of electrochemically deposited black chrome coatings on nickel plated steel in the presence of graphite encapsulated FeCo nanoparticles. Electrodeposition was carried out on SS strips under galvanostatic condition in a solution containing 275 g/L of CrO3, 0.2 g/L of NaF, 3 g/L of sodium nitrate, operating at a pH of 0.3, in the presence of 0.025, 0.05 and 0.1 % by weight of graphite encapsulated FeCo nanoparticles. The anode employed was sacrificial lead. The electrolyte bath was constantly stirred at 200 rpm to enable the deposition of the nanoparticles along with black chrome. EDX and SEM analysis have confirmed the co-deposition and evenly spread of graphite encapsulated nanoparticles on the black chrome coating surface. A solar selectivity of 8.08 (α = 0.97, ε = 0.12) was reported. The thermal and corrosion stability of the coatings are enhanced after co-deposition of graphite encapsulated nanoparticles. Thermal analysis of the coatings indicated that though initial degradation started at 250 °C, weight loss was not predominant till 350 °C.

Black chrome has emerged as a strong candidate for an absorber surface because of its good solar selective properties and long-term durability. The process, however, has low cathode efficiency, consequently the bath operates at high currents making the cooling requirements mandatory for the efficient operation. In spite of hazardous nature, the hexavalent chromium electrolytes are still widely used to produce thin black chrome coatings due to their versatile properties, viz, excellent corrosion resistance, high hardness, low friction, and resistance to abrasive wear [39, 41].

REFERENCES

[1] D. Bregnbak; J.D. Johansen; M.S. Jellesen; C. Zachariae; T. Menné; J.P. Thyssen: Chromium allergy and dermatitis: Prevalence and main findings, Contact Dermatitis, 73(2015)5, 261–280, Doi: 10.1111/cod.12436
[2] D. Basketter; L. Horev; D. Slodovnik; S. Merimes; A. Trattner; A. Ingber: Investigation of the threshold for allergic reactivity to chromium, Contact Dermatitis, 44(2000)2, 70–74, Doi: 10.1034/j.1600-0536.2001.440202.x
[3] L.O. Gilbert; C.C. Buhman: Black chromium plating, U.S. Patent 2,623,847A, (1952)
[4] M.F. Quaely: Black chromium base electroplating, Plating, 9(1953), 982–986
[5] A.K. Graham: A black chromium plating process, Proc. Amer. Electroplaters Soc., 46(1959), 61–63
[6] J.P. Branciaroli; P.G. Stutzman: Black chrome plating, application and deposit characteristics of a new plating process, Plating, 56(1969)1, 37–43
[7] J.P. Branciaroli: Black chrome plating – the practical side, Trans. Inst. Met. Finish., 48(1970)1, 172–174, Doi: 10.1080/00202967.1970.11870150
[8] L. Sivaswamy; S. Gouri; B.A. Shenoi: Electro deposition of black chrome from tetrachromate bath, Metal Finish., 72(1974)3, 48–51
[9] R. Chang; W.F. Hall: On the correlation between optical properties and chemical/metallurgical constitution of Cr2O3/Cr thin films, AlP Conf. Proceedings, 40(1977), 305–310, Doi: 10.1063/1.31152
[10] P.M. Driver; R.W. Jones; C.L. Riddiford; R.J. Simpson: A new chrome black selective absorbing surface, Solar Energy, 19(1977), 301–306, Doi: 10.1016/0038-092X(77)90074-3
[11] K.J. Cathro: Black chrome for solar collectors: Deposition from tetrachromate baths, Met. Finish., 76(1978)10, 57–62, hdl.handle.net/102.100.100/301451?index=1
[12] A.R. Balakrishnan; K.G.T. Hollands; E.C. Shewen; P. Niessen: Optimization Studies on Black Chrome Electroplating Variables for Solar Selective Surfaces, in Renewable Alternatives, Vol. 1, Winnipeg, Manitoba, Solar Energy Society of Canada, Inc., (1978), 1.1.6.1.–1.1.6.11
[13] G.A. DiBari; P.P. Turillon: Effect of corrosion on selectivity of electrodeposited black chromium with and without nickel underlayers, in Sun II, Proceedings of the International Solar Energy Society Congress, Atlanta, May 28 to June 1, 1979, K. W. Böer; B. H. Glenn (Editors), Pergamon Press, New York, Vol. 3, (1979), 1917
[14] S. Berthier; J. Lafait: Black chromium coatings: Experimental and calculated optical properties using inhomogeneous medium theories, J Phys. (Paris) 40(1979), 1093–1103, Doi: 10.1051/jphys:0197900400110109300
[15] G.J. Clark; Z. E. Switkowski; R.J. Petty; J. C. P. Heggie: Analysis of chrome-black solar-absorber surfaces, J Appl. Phys., 50(1979)7, 4791–4793, Doi: 10.1063/1.326540
[16] J. Spitz; T.V. Danh; A. Aubert: Chromium black coatings for photothermal conversion of solar energy, Part I: Preparation and structural characterization, Solar Energy Mater., 1(1979)3–4, 189–200, Doi: 10.1016/0165-1633(79)90037-6
[14] J.M. Behaghel; S. Berthier; J. Lafait; J. Rivory: Chromium black coatings for photothermal conversion of solar energy, Part II: Optical properties, Solar Energy Mater., 1(1979)3–4, 201–213, Doi: 10.1016/0165-1633(79)90038-8
[18] P.K. Gogna; K.L. Chopra: Optical and topographical properties of selective black chrome, Thin Solid Films, 63(1979), 183–187, Doi: 10.1016/0040-6090(79)90123-8
[19] D.M. Fell; L.L. Tongson; S.V. Krishnaswamy; R. Messier; I.S.T. Tsong: Characterization of Commercial Black Chrome Coatings, J Vac. Sci. Technol. 17(1980), 358–361, Doi: 10.1116/1.570387
[20] P.M. Driver: An electrochemical approach to the characterisation of black chrome selective surfaces, Solar Energy Mater., 4(1981), 179–202, Doi: 10.1016/0165-1633(81)90041-1
[21] O.T. Inal; M. Valayapetre; L.E. Murr; A.E. Torma: Microstructural and mechanical property evaluation of black-chrome coated solar collectors-II, Solar energy mater., 4(1981)3, 333–358, Doi: 10.1016/0165-1633(81)90070-8
[22] N. Vasudevan; V.K. William Gripps; I. Rajagopalan: The present status of black chromium plating, Surface Technol., 14(1981)2, 119–132, Doi: 10.1016/0376-4583(81)90073-X
[23] P.M. Driver; P.G. McCormick: Photothermal degradation of black chrome - a possible contributing factor, J Phys. (Paris) 42(1981)C1, 309–315, Doi: 10.1051/jphyscol:1981121
[24] D.P. Grimmer, R.K. Collier: Black chrome solar-selective coatings electrodeposited on metallized glass tubes, Solar Energy, 26(1981)5, 467–469, Doi: 10.1016/0038-092X(81)90230-9
[25] P.M. Driver; P.G. McCormick: Black chrome selective surfaces I. Deposit growth and properties, Solar Energy Mater., 6(1982)2, 159–173, Doi: 10.1016/0165-1633(82)90017-X
[26] P.M. Driver; P.G. McCormick: Black chrome selective surfaces II. Degradation at elevated temperatures, Solar Energy Mater., 6(1982)4, 381–402, Doi: 10.1016/0165-1633(82)90026-0
[27] R.B. Pettit; R.R. Sowell; I.J. Hall: Black chrome solar selective coatings optimized for high temperature applications, Solar Energy Mater., 7(1982)2, 153–170, Doi: 10.1016/0165-1633(82)90081-8
[28] J. Takadoum: Black coatings: A review, Eur. Phys. J. Appl. Phys., 52(2010)3, epjap2010155, Doi: 10.1051/epjap/2010155. hal-00646463
[29] S. Surviliene; L. Orlovskaja; S. Biallozor: Black chromium electrodeposition on electrodes modified with formic acid and the corrosion resistance of the coating, Surf. Coat. Technol., 122(1999)2–3, 235–241, Doi: 10.1016/S0257-8972(99)00254-6
[30] M. Aguilar; E. Barrera; M. Palomar-Pardavé; L. Huerta; S. Muhl: Characterization of black and white chromium electrodeposition films: surface and optical properties, J Non-Cristal. Sol., 329(2003)1–3, 31–38, Doi: 10.1016/j.jnoncrysol.2003.08.008
[31] C.E. Kennedy: Review of mid-to high- temperature solar selective absorber materials, National Renewable Energy Laboratory, Technical Report: NREL/TP-520-31267, July 2002. www.nrel.gov/docs/fy02osti/31267.pdf
[32] N.V. Mandich; Donald L. Snyder in Modern Electroplating, 4th Edition, M. Schleinger; M. Pavnovic (Editors), Electrochemical Society Series, New Jersey, John Wiley, New York (2000), 326
[33] D.L. Snyder: Decorative chromium plating, Met. Finish., 98(2000)1, 215–222, Doi: 10.1016/S0026-0576(00)80328-1
[34] D.L. Snyder: Metal Finishing 65th Guide book, 95(1997)1A, 211
[35] M. Daryabegy; A.R. Mahmoodpoor: Method of manufacturing absorbing layers on copper for solar applications, Renewable Energy Organization of Iran, 2(2006), 35–39
[36] G.E. McDonald: Spectral reflectance properties of black chrome for use as a solar selective coating, Solar Energy, 17(1975)2, 119–122, Doi: 10.1016/0038-092X(75)90067-5.
[37] J. Quintana; P.J. Sebastian: The influence of various substrate treatments on morphology and selective absorber characteristics of electrochemical black chrome, Sol. Energy Mater. Sol. Cells, 33(1994)4, 465–474, Doi: 10.1016/0927-0248(94)90006-X
[38] A.R. Shashikala; R. Uma Rani; A.K. Sharma; S.M. Mayanna: Studies on solar selective black chrome plating on aluminum alloys, Galvanotechnik, 97(2006)10, 2387–2400
[39] K.D. Lee: Preparation and characterization of black chrome solar selective coatings. J Korean Phys. Soc., 51(2007)1, 135–144. file:///C:/Users/DELL/Downloads/JP-51-1-135.pdf
[40] K.S. Wilson: Process of black chromium plating, U.S. Patent 3,620,935, (1969), Harshaw Chemical Company, Cleveland, Ohio
[41] S. Jafari; S.M. Rozati: Characterization of black chrome films prepared by electroplating technique, World renewable energy congress, 8–13 May 2011, Sweden, (2011), 3999–4005. Doi: 10.3384/ecp110573999
[42] I.D.M. Medeiros; K.C. Gomes; R.P.N. Goncalves; G.O. Galvao: Selective solar surface solar based on black chromium: influence of electrodeposition parameters in the absorption of surfaces, Mater. Res., 22(2019)2, e20180625, Doi: 10.1590/1980-5373-mr-2018-0625
[43] V.S. Protsenko; F.I. Danilov: Chromium electroplating from trivalent chromium baths as an environmentally friendly alternative to hazardous hexavalent chromium baths: comparative study on advantages and disadvantages, Clean Technol. Environ. Policy, 16(2014), 1201–1206, Doi: 10.1007/s10098-014-0711-1
[44] J. Gyllenspetz; S. Renton: Trivalent chromium electroplating baths and electroplating therefrom, U.S. Patent 3,954,574, (1976)
[45] R. Macary; D. Tailor: Black Chromium Finishing: Beauty and the Beast, www.pfonline.com/articles/black-chromium-finishing---beauty-and-the-beast
[46] Z. Abdel Hamid: Electrodeposition of black chromium from environmentally electrolyte based on trivalent chromium salt, Surf. Coat. Technol., 203(2009), 3442–3449, Doi: 10.1016/j.surfcoat.2009.05.022
[47] V. Moise; R. Cloots; A. Rulmont: Study of the electrochemical synthesis of selective black coatings absorbing solar energy, Int. J Inorg. Mater., 3(2001)8, 1323–1329, Doi: 10.1016/S1466-6049(01)00154-4
[48] M.R. Bayati; M.H. Shariat; K. Janghorban: Design and chemical composition and optimum working conditions for trivalent black chromium electroplating bath used for solar thermal collectors, Renewable Energy, 30(2005)14, 2163–2178, Doi: 10.1016/j.renene.2005.02.003
[49] R.A.X. Nunes; V.C. Costa; W. Sade; F.R. Araújo; G.M. Silva: Selective surfaces of black chromium for use in solar absorbers, Meter. Res., 21(2017)1, e20170556, Doi: 10.1590/1980-5373-MR-2017-0556
[50] S. Surviliene; A. Cesuniene; R. Juskenas; A. Selskiene; D. Bucinskiene; P. Kalinauskas; K. Juskevicius; I. Jureviciute: The use of trivalent chromium bath to obtain a solar selective black chromium coating, Appl. Surf. Sci., 305(2014), 492–497, Doi: 10.1016/j.apsusc.2014.03.122
[51] B. Usmani; S. Harinipriya; N. Kumar; V. Gupta: Solar selective coatings with enhanced thermal and corrosion stability: electrochemically deposited black chrome on stainless steel in the presence of graphite encapsulated FeCo nanoparticles, Adv. Mater. Res., 875–877(2014) 388–393, Doi: 10.4028/www.scientific.net/AMR.875-877.388
[52] C. Siva kumar; S.M. Mayanna; K.N. Mahendra; A.K. Sharma; R. Uma Rani: Studies on white anodizing on aluminum alloy for space applications, Appl. Surf. Sci., 151(1999), 280–286, Doi: 10.1016/S0169-4332(99)00290-1
[53] A.K. Shanna: Gold plating on aluminum alloys for space applications, Trans. Inst. Met. Finish., 67(1989)1, 87–88, Doi: 10.1080/00202967.1989
[54] C.N. Taramani; B.M. Maruthi; S.M. Mayanna: Development of a Non- cyanide Alkaline Bath for Industrial Copper Plating, Trans. Inst. Met. Finish., 80(2002)2, 37–39, Doi: 10.1080/00202967.2002.11871427
[55] A. Sato; R. Barauskas in Modern Electroplating, 4th Edition, M. Sehleinger; M. Pavnovic (Editors), Electrochemical society series, New Jersey, John Wiley. New York, (2000), 105
[56] G.A. DiBari in Modern Electroplating, 4th Edition, M. Sehleinger; M. Pavnovic (Editors), Electrochemical Society Series, New Jersey, John Wiley, New York, (2000), 147
[57] K. Salnikow; A. Zhitkovich: Genetic and epigenetic mechanisms in metal carcinogenesis and cocarcinogenesis: nickel, arsenic, and chromium, Chem. Res. Toxicol., 21 (2008)1, 28–44, Doi: 10.1021/tx700198a
[58] Occupational Exposure to Hexavalent Chromium, US Dept. of Labor, OSHA (Occupational Safety and Health Administration) Federal Register # 71:10099-10385, 28 Feb 2006

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  • Ausgabe: 9
  • Jahr: 2021
  • Autoren: Dr. Anand Kumar Sharma

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