Struktura i właściwości warstw kompozytowych na osnowie amorficznego niklu modyfikowanych wolframem lub tlenkiem niklu

• Autorzy: Popczyk M. , Budniok A. , Cybo J. , Służałek G.

Warianty tytułu

EN

Structure and properties of composite layers on the basis of the amorphous nickel modified of tungsten and nickel oxide

• Języki publikacji: PL

Abstrakty

PL

Elektrolityczne warstwy kompozytowe Ni-P+W i Ni-P+NiO+W otrzymano w warunkach galwanostatycznych (j = 0,200 A/cm2), w temperaturze 298 K, z elektrolitu do niklowania, zawierającego w jednym przypadku proszek wolframu, a w drugim - proszek wolframu i tlenek niklu. Dla celów porównawczych otrzymano również warstwy Ni-P, które poddano identycznym badaniom jak pozostałe. Analiza składu fazowego otrzymanych warstw została przeprowadzona na dyfraktometrze Philips, a analiza składu chemicznego - metodą atomowej absorpcji za pomocą spektrofotometru atomowej absorpcji. Mikroskop metalograficzny oraz mikroskop stereoskopowy, profilografometr Form Talysurf i mikroanalizator rentgenowski zastosowano w celu scharakteryzowania zgładów poprzecznych oraz powierzchni otrzymanych warstw. Wprowadzenie proszku wolframu w jednym przypadku oraz proszku wolframu i tlenku niklu w drugim przypadku do elektrolitycznej osnowy Ni-P powoduje otrzymanie warstw o rozwiniętej, chropowatej powierzchni. Warstwy te charakteryzują się miejscowo zróżnicowanym składem chemicznym swoich składników, co może być przydatne podczas ich stosowania jako materiały elektrodowe w elektrochemii.

EN

Electrodeposited Ni-P+W and Ni-P+NiO+W composite layers were obtained in the galvanostatic conditions at the current density//„,, = 0.200 A/cm2 with the following electrolyte (g/dm3): 28 NiSO4 • 7H2O, 32 NaH2PO2 • H2O, 5 NH4C1, 9 H3BO3, 8 CH3COONa, 29 C6H5O7Na3 • 2H2O, 40 W in the one case (Ni-P+W) and 100 NiO and 40 W in the other (Ni-P+NiO+W). Twice distilled water and Analytical grade" reagents were used for preparation of electrolytes. For comparision the Ni-P layer was also obtained and investigated in the same manner. The phase composition of the layers was performed by the X-ray diffraction (XRD) method using a Philips diffractometer and the CuKa radiation. The chemical composition of the layers was determined by the atomic absorption method using a Perkin-Elmer spectrometer. Metallographic microscope, stereoscopic microscope, Form Talysurf - type profilograph and X-ray microanalyser were used for cross-section and surface characterisation of the composite layers. All Ni-P, Ni-P+W and Ni-P+NiO+W layers electrolytically deposited, show good adhesion to the copper substrate. In con­tradistinction from smooth Ni-P layers, obtained Ni-P+W and Ni-P+NiO+W composite layers to characterize of a mat and rough surface, with visible grains of embedded powder. The surfaces of Ni-P+W and Ni-P+NiO+W composite layers are more developed in comparision to Ni-P layer, with proportionate of distribution grains of nickel oxide and tungsten (Fig. 1 and Fig. 2). Linear analysis of distribution of nickel and tungsten in the Ni-P+W and Ni-P+NiO+W composite layers, show o local differentiation of chemical composition of the elements. In the places, where to observe a minimum of capacity of nickel, to observe maximum of capacity of tungsten and inversely (Fig. 3a and 3b). The Ni-P+W layer contains about 71% of nickel, about 14% of phosphorus and about 15% of tungsten. The Ni-P+NiO+W layer contains about 74% of nickel, about 13% of phosphorus, about 5% of nickel oxide and about 8% of tungsten. XRD investigations show that the amorphous structure of the Ni-P matrix is retained in the Ni-P+W and Ni-P+NiO+W layers (Fig. 4a.2 and 4b.2). Besides the wide reflex of Ni-P matrix, characteristic for crystalline tungsten in the one case and the crystalline nickel oxide and tungsten in the other built in the matrix are visible. This confirms unequivocally the composite character of the Ni-P+W and Ni-P+NiO+W layers. XRD investigations after heat treatment at the temperature of 500°C show a crystallization of the Ni-P amorphous matrix to the suitable nickel phosphides (Fig. 4a.l and 4b.l). In this layers, near a new phase of nickel phosphide, are embedded anteriorly composite ingredients, tungsten and nickel oxide. The process of thermal crystallization of the matrix of consolidated their embedde in the layer. The surface image of this layers undergo a change (Fig. la.2, lb.2 and Fig. 2a.2, 2b.2). After heat treatment of the layers undergo a change values of roughness factor Ra surfaces of the composite layers. For the Ni-P+NiO+W layer after heat treatment, to observe the decrease of the of roughness factor Ra surface in comparison to the same layer before heat treatment, however for the Ni-P+W layer after heat treatment, to observe the increase of the of roughness factor Ra surface in comparison to the same layer before heat treatment (Tab. 1). It means, that in results of heat treatment, layers without nickel oxide in the matrix (Ni-P i Ni-P+W) no undergo an agglomeration, and the matrix of crystallize is a causing of increasing development of surface degree. Electrolytic composite Ni-P+W is formed of amorphous matrix and the crystalline tungsten embedded in it, however electrolytic composite Ni-P+NiO+W is formed of amorphous matrix and the crystalline tungsten and nickel oxide embedded in it. Introduction of tungsten powder in the one case, and nickel oxide and tungsten powder in the other to electrolytic Ni-P matrix is a causing of obtaining layers about very rough surface. Thus obtained layers, to characterize a local differentiation of chemical composition of the elements, what maybe useful in application of this layers as electrode materials in electrochemistry.

Słowa kluczowe

PL

kompozyty; warstwa kompozytowa; modyfikacja; wolfram; tlenek niklu; struktura; właściwości

EN

composites; composite layer; tungsten; nickel oxide; structure; properties

• Wydawca: Wydawnictwo Politechniki Częstochowskiej
• Czasopismo: Kompozyty
• Rocznik: 2002
• Tom: R. 2, nr 3
• Strony: 68--72
• Opis fizyczny: Bibliogr. 5 poz.,tab., wykr., rys.

Twórcy

autor

Popczyk M.

• Uniwersytet Śląski, Instytut Fizyki i Chemii Metali, ul. Bankowa 12, 40-007 Katowice

autor

Budniok A.

• Uniwersytet Śląski, Instytut Fizyki i Chemii Metali, ul. Bankowa 12, 40-007 Katowice

autor

Cybo J.

• Uniwersytet Śląski, Katedra Materiałoznawstwa, ul. Śnieżna 2, 41-200 Sosnowiec

autor

Służałek G.

• Uniwersytet Śląski, Katedra Materiałoznawstwa, ul. Śnieżna 2, 41-200 Sosnowiec

Bibliografia

• [1] Scott K., Electrochem. Processes for Clean Technology, Univ. of Newcastle, 33, 34.
• [2] Arul I., Vasu K., J. Appl. Electrochem. 1990, 20, 32.
• [3] Parsons R., Van der Noot T., J. Electroanal. Chem. 1988, 9, 257.
• [4] Fan Ch., Piron D.L., Sur. and Coat. Tech. 1995, 73, 91.
• [5] Keddam M., Seyarich S., Takenouti H., J. Appl. Electrochem. 1994, 24, 1037.