theory of metal passivation — страница 2

  • Просмотров 2115
  • Скачиваний 103
  • Размер файла 54

shall designate Pa ar0 , . Their speeds . These values represent quantity of the acts taking place in 1 cm2 of the surface M for 1 sec. They are proportional to superficial concentration na of particles of the given size and probabilities of the elementary acts . Resulting speed of direct and return transitions . At balance state Proceeding from this it is possible to find out Further we shall define A1 and A2. Proceeding from this it is possible to calculate the speed of cluster formation With the help of this formula it is possible to define the laws of formation of the passive layer on the sector II (in pic.1). Then taking in to account the energetic inhomogeneity of metal surface it is possible to find out the integrated current density where - bond energy. To each

pair value of corresponds the certain probability I(, i) of formation of twin cluster and the local degree of filling by them ith platforms of the surface M. With the growth of potential  formation of cluster becomes more and more intensive. And accordingly grows the integrated degree of its filling by cluster, Thus the processing of the first thin superficial layer of metal in oxide is finished. Take place complete passivation of the surface M, the sector II on the curve (fig. 1) is replaced by the sector III, for which the new physical conditions must be taken in account. And further researched may be done. 1