PREPARATION AND CHARACTERIZATION OF COMPOSITE TIN CHEVREL-PHASE PBMO6S8 AND TIN TITANIUM NIOBIUM CARBONITRIDE TI0.63NB0.34C0.38N0.58

The composite coatings of Sn-PbMo6S8 (PbMo6S8 content 28-88 wt.%), Sn- NbCxNy (NbCxNy content 10-88 wt.%) and Sn-Ti0.63Nb0.34C0.38N0.58 (Ti0. 63Nb0.34C0.38N0.58 content 55-70 wt.%) were electrodeposited from pota ssium pyrophosphate Sn(IV) and Sn(LI) complex salt K-8[Sn(P2O7)(3)], K -6[Sn(P2O7)(2)] electrolytes containing cation active organic substanc es alkylbenzyltrimethylammonium (I) or alkyldiethanolbenzylammonium (I I) chlorides. The structure of the composite coatings was dependent on the conditions of electrodeposition, the disperse phase content and t he thermal treatment was investigated by means of scanning electron mi croscopy. It was determined that pores or crevices which may form, dep ending on the conditions of electrodeposition, can be prevented by mea ns of a thermal treatment for 4-8 h at. 260, 280 and 310 degrees C. Th e composite coatings of Sn-PbMo6S8 obtained with a PbMo6S8 content > 5 4 wt.% are superconductive coatings. The Sn-Ti0.63Nb0.34C0.38N0.58 coa tings are conductive coatings. The Sn-NbCxNy coatings are corrosion re sistive coatings at a temperature of 40 +/- 10 degrees C and relative humidity of 98% The Sn-NbCxNy with NbCxNy content up to 30 wt.% are so lderable coatings at a temperature of 310 degrees C. (C) 1998 Elsevier Science S.A. All rights reserved.