Rezumat
A possible application of the iron nano- and microparticles as carriers of palladium and platinum catalysts is shown. The increase of efficiency of the catalytic activity by a factor of 2 up to 5 is achieved by micromixing the reactive medium by means of magnetic fields with variable direction of magnetic intensity gradient. It is also possible to prepare such composite materials as iron – silver, iron – gold for application in electrical engineering. Procedures are described for the obtaining of catalytic and conducting materials based on chemical deposition of metals on iron particles. A possibility is shown for using the galvanic and engi- neering methods to form metallic sheathing on particles of magnetic current – carrying materials. The resis- tivity of copper sliding contacts obtained with using of the suggested method and containing graphite and iron microinclusions is ρ = 2–3⋅10-6 Ohm⋅cm, whereas graphite sliding current collectors are of ρ = 800⋅10-6 Ohm⋅cm. At the same time, the wear resistance becomes 12–15 times higher as well as the operation life. It is shown that chemical passivation of the surface of nano- and microparticles of iron can prevent them from reaction with diluted nitric acid. Prospects for the iron particles utilization in X-ray contrasting anatomical preparations of intraosteal blood system have been investigated. To increase the density of capillary net filling with contrast particles it is proposed to apply the magnetic field with variable direction of magnetic intensity gradient in the course of technological process. It enables the density of intraosteal capillary net filling to reach 75% of the nolume.