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[en] Nickel/titanium alloys having a nickel:titanium atomic ratio between about 1:02 and 1:13 and a vanadium content between about 4.6 and 25.0 atomic percent show constant stress versus strain behavior due to stress-induced martensite in the range from about 0⁰ to 60⁰ C

No abstract available

No abstract available

No abstract available

[en] Experimental and theoretical investigations were made of the nature of energy absorption by a ferrite at a high parametric pump power. The kinetic instability appeared at a pump power exceeding by 18-20 dB the parametric excitation threshold. This instability created nonequilibrium packets of secondary spin waves which were not in resonance with the pump. A theory of the interaction of secondary and parametric spin waves was developed. Measurements were made of the imaginary part of the nonlinear susceptibility of the investigated ferrite as a function of the excess of the pump power above the kinetic instability threshold in magnetic fields from 1,040 to 1,290 Oe. The predictions of the theory were compared with the experimental results

[en] Ti-Ni shape memory alloy thin films were deposited using an RF magnetron sputtering apparatus. The as-sputtered films were heat-treated in order to crystallize and memorize. After the heat treatment, the shape memory characteristics have been investigated using DSC and thermomechanical tests. Upon cooling the thin films, the solution-treated films showed a single peak in the DSC curve indicating a single stage transformation occurring from B2 to the martensitic phase, while the age-treated films showed double peaks indicating a two-stage transformation, i.e., from B2 to the R-phase, then to the martensitic phase. A perfect shape memory effect was achieved in these sputter-deposited Ti-Ni thin films in association both with the R-phase and martensitic transformations. Transformation temperatures increased linearly with increasing applied stress. The transformation strain also increased with increasing stress. The shape memory characteristics were strongly affected by heat-treatment conditions. (author)

[en] Coincident carbon and boron solubility measurements on a carburized Fe-B alloy were used to determine the influence of carbon on boron solubility at temperatures from 800 to 1000 C. Carbon solubility was obtained from martensite hardness. Soluble boron levels were measured using the neutron autoradiography (NA) technique. Quantitative aspects of the NA technique were reviewed, and a model was developed to determine soluble boron levels from track density measurements. A new solid state NA track detector material (CR-39) was shown to provide improved etched track characteristics. Measured boron solubility in Fe indicated that the α/γ/Fe₂B reaction is a eutectoid rather than a peritectoid type. The influence of carbon on boron solubility was evaluated and the results indicate that higher carbon levels result in decreased boron solubility values

[en] An austenitic nickel-chromium-iron base alloy is described consisting essentially of: about 0.04 to 0.09 wt. % carbon; about 1.5 to 2.5 wt. % manganese; about 0.5 to 1.6 wt. % silicon; about 0.035 to 0.08 wt. % phosphorus; about 13.3 to 16.5 wt. % chromium; about 13.7 to 16.0 wt. % nickel; about 1.0 to 3.0 wt. % molybdenum; about 0.10 to 0.35 wt. % titanium; up to about 0.20 wt. % zirconium; wherein for zirconium contents from 0.02 to 0.20 wt. % the carbon and phosphorus contents are selected from the group consisting of about 0.05 to 0.08 wt. % phosphorus and about 0.04 to 0.09 wt. % carbon, about 0.035 to 0.08 wt. % phosphorus and about 0.07 to 0.09 wt. % carbon, and about 0.05 to 0.08 wt. % phosphorus and about 0.07 to 0.09 wt. % carbon; and the balance of the alloy being essentially iron

[en] The shape memory effect is associated to a martensitic transformation in many materials. It consists in the ability of the material to recover its original shape after being deformed through or in the martensitic phase. This shape recovery occurs because the same parent phase is obtained after the retransformation. However, it is shown in this work that under very special circumstances two differently oriented variants of the parent phase can be obtained from a martensite single-variant. This breakdown of the shape memory effect was found after transforming a single-crystal into a unique plate of martensite by single interface-growth. During the retransformation two variants of parent phase appeared which were related to each other by the martensite symmetry operations (symmetry group C_2h). The experimental results consist of those obtained applying the W-L-R phenomenological theory. (Author)