Alloys of the AI -Mg system are characterized by an elevated corrosion resistance and ductility and good casting properties. The strength of these alloys depends considerably on the concentration of the main alloying element, namely, magnesium. Alloying with small amounts of transition metals, for example, Ti, Zr, Cr, Sc, affects markedly the structure and properties of AI -Mg alloys. The present work is devoted to the structure and properties ofAl -Mg alloys alloyed with scandium.Mechanical properties of hardened alloys of the AI-Mg system alloyed with Sc, Ti, Mn, Cr, and Be are presented in Table I. It can be seen that the highest strengthening is attained when the magnesium concentration in the alloy is 8%. The effect of the concentration of scandium on the mechanical properties of the AI -8% Mg alloy is presented in Fig. 1.

The thermomechanical stability of the anion–cation exchange matrix “Polikon AC” on viscose nonwoven materials is investigated. In this work, a molecular model of a solvation environment for experimentally obtained “Polikon AC” mosaic membranes is refined. Mosaic membranes on a viscose fiber base were fabricated by the method of polycondensation filling. The temperature dependence of deformation was investigated for dry and wet anion and cation exchange membrane components at a constant tensile load of 1.5 N and a heating rate of 8 °C/min. The effect of moisture content on the deformation of anionite and cationite fragments under a constant external tensile load of 1.5 and 3 N in a temperature range up to 100 °C was studied.

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All industrial alloys of the AI-Mg system correspond to the region of the a-solid solution of the phase diagram. Domestic alloys AL8 and AL27-1 and foreign alloys 520 (USA) and LM-10 (Great Britain) with a high magnesium content (9 -11%) have high mechanical properties after quenching. However, they possess a high sensitivity to natural aging under conditions of long-term operation or storing, which causes their embrittlement. The aim of the present work consists in developing an AI-Mg-base composition quenched and aged artificially that will possesses a high strength (err = 380-400 N/ram 2) and will not change in operation at a temperature of at most 100~We chose alloy AL27-1, which is the strongest domestic alloy of the AI -Mg system for our study. In order to choose an optimum composition we used the method of experiment design with a Schaeffer simplex lattice of the third order. Figure I presents the dependences of the mechanical properties of quenched alloy AL27-1 (10.2% Mg, 0.08% Ti, 0.11% Zr, < 0.05% Fe, < 0.l% Si, the remainder AI) on the regimes of artificial aging. After quenching from 435 + 5~ (20h) in water with G=100~ the alloy has G = 375 N/mm 2, 8 = 22.0%. An analysis of the obtained results has shown that artificial aging in the studied range of tema t, ~ peratures and hold times does not cause an additional oo ~xyg~ strengthening of the quenched alloy. An increase in the hold temperature and time for every temperature of artificial aging 2 ~ ~ N/ram2 decreases the strength and the elongation of the quenched alloy, i so~/ ~a~ In accordance with triple-phase diagrams we introduced /%N2\ additional elements into the binary AI-Mg alloy in combi-100.,/ ]G.~-----~-N-..,~ nations and amounts that would prevent the formation of an embrittling !3-hase, namely, 6 -16% Mg, 0 -5% Zn (in order so. to increase the strength), O-2% Mn (in order to decelerate 6 27 ~, h 48 the diffusion processes of the decomposition of the solid sot, ~ lution and increase its stability), O-2% Sb (in order to inoo "~ a, crease the stability of the solid solution, improve the corro2oo sion resistance and decrease the crack formation), and 0-~ 0.05% Zr (in order to disintegrate the structure). After the exis0~-~14 x periments and a mathematical analysis of the results we have chosen an optimum composition for the alloy.Ioor 20 ~--~\ We conducted a comparative metallographic and differ-/ ential thermal (DTA) analysis of alloy AL27-1 and an experi-50.L 6 2'7 48