Sodium orthovanadate was tested as a corrosion inhibitor of intermetallic Al2Cu in 1 M H3PO4. The Al2Cu – H3PO4 – Na3VO4 system was studied using the following methods: inductively coupled plasma optical emission spectrometry, scanning electron microscopy with energy dispersive x-ray spectroscopy, x-ray diffraction, electrochemical impedance spectroscopy, polarisation and open circuit potential. It was found that the corrosion rate decreased as the inhibitor concentration increased. The highest inhibition efficiency 99% was obtained when sodium orthovanadate initial concentration was equal to 100 mM, pH = 1.11, due to precipitation of a protective layer of insoluble salt, containing vanadium, phosphorus, sodium and oxygen, on the surface. At pH = 0.76 the protective layer was not formed and inhibition efficiency decreased to 76%. Selective corrosion of the intermetallic phase caused a significant increase of an electric double layer capacitance and decrease of a charge transfer resistance.

The paper presents preliminary results of the investigations of the correlations occurring between the rate of the acoustic emission (AE) events and the plastic deformation mechanisms during channel-die compression of Mg-Li and Mg-Li-Al alloys. as well as the corresponding metallic matrix composites reinforced with short ó Al2O3 fibres. Essential qualitative and quantitative differences in the AE behaviour have been observed in the composites and in the pure alloys. The obtained results are discussed on the basis of the possible dislocation and microcracking processes and also on the basis of microstructure observations using the optical microscopy. It is suggested that the highly jumping character of AE behaviour in two-phase (a+ /3) Mg8Li3AI alloys is related to the twinning in a phase and to the microcracking along the interfaces. while in Mg8Li + bAl2O3 composites also to the fibres cracking and debonding processes, i.e. the loss of cohesion between the fibres and the matrix.

The chemical fundamentals of one variant of the chelate method of combined removal of sulfur and nitrogen oxides from flue gases were described. Special attention was paid for chemical reactions responsible for production of solid wastes. A flow sheet of the technology was presented and the operation of industrial installation of SO2, NOx and dust from combustion gases of two 29 MW, grate boilers each was described. The material balance of the process was made and the quantity of solid wastes produced during 3 weeks test of the technology was presented.