The review of the beryllium-copper diagram and the determination of the beryllium-nickel-copper diagram were carried on by means of thermal and X-ray analyses, dilatometric observation and hardness measurement as well as microscopic observation. The experiment on the ternary equilibrium diagram was made in the composition range of alloys less than 13% of Be.
The results obtained on the beryllium-copper diagram are as follows.
(1) The non-variant reaction concerning melt taking place in the range of 4.6-2.2% Be is not the peritectic reaction L+α→β, but is the eutectic reaction L→α+β.
(2) The formation of the minimum point on the liquidus curve of β-phase, which has been shown in many) iteratures, does not exist, the primary crystallization temperature being raised graduallyy with the increase in nickel content.
(3) γ-phase precipitates α-phase at lower temperature till the homogeneous range of γ-phase shifts to the composition more than 12 per cent of beryllium.
The ternary equilibrium diagram of Be-Ni-Cu system is shown in Fig. 4.
(4) The solid solubility curve of α-phase immediately after the solidification lies on the line connecting the following points: 2.0% Ni-0.5% Be, 5.0% Ni-0.3% Be, 10.0% Ni-0.3% Be, 30.0% Ni-0.5% Be, 60.0% Ni-1.4% Be, 80.0% Ni-2.2% Be; and the solubility curve at 500° shifts to the line formed by connecting the points: 2.0% Ni-less than 0.05% Be, 5-0% Ni- less than 0.05% Be, 10.0% Ni-less than 0-1% Be, 30.0% Ni-less than 0.1% Be, 60.0% Ni-0.3% Be, 80.0% Ni-0.7% Be.
(5) The homogeneous β-phase structure is only found in alloys of composition less than 2.0% Ni whatever the, Be-content may be.
(6) The solid solution γ based on the compound NiBe in the nickel-beryllium system form the continuous solid solution with the γ-phase based on CuBe in the beryllium-copper system.
(7) There are three, primary surfaces of α-, β- and γ-phases in the investigated range of composition.
(8) In the ternary equilibira concerning melt there exists only one non-variant reaction, which is the peritecto-eutectic reaction at 868°, L+γ_??_α+β, the compositions of the melt, γ, α and β being 4.4% Ee-0.8% Ni-Bal. Cu, about 13.7% Be-59% Ni-Bal. Cu, 0.8% Be-1.6% Ni-Bal, Cu and about 2% Ni-5.7% Be-Bal. Cu respectively.
(9) The temperatures of the binary eutectoid change of the β phase into α+γ raise with the increase of nickel until the temperature of the above shown peritecto-eutectic reaction is reached.
(10) The change of temperatures of the binary eutectoid reaction was shown by the dilatometric analysis, the formation of the ternary continuous solid solution γ was verified by Zeemann-Bohlin X-ray analysis, and the reactions such as peritecto-eutectic, change were clarified by the microscopic examination.

抄録全体を表示

The relation between the composition and the physical and mechanical properties of heat treated copper base ternary alloys was investigated, and optinum relation in their composition, by which the electrical conductivity and the age-hardenability are especially improved, was found to exist as follows; the ratio of the content of nickel and beryllium in such alloys is nearly 5:1 in weight.
The diagrammatic consideration on the change of the electric conductivity and the age-hardenability due to the vari tion of the composition was carried out, and its relation was clarified; in such alloys as their both conductivity and age-hardenability can be significantly improved, the solid solubility change of the α-phase is not only large, but its purity after tempering becomes high, that is, its composition is gradually approached to the, pure copper by the precipitation of the ternary γ-phase. Besides this fact it must be noted that the ratio of the amount of α-phase to that of γ-phase is enlarged by the addition of small amount of nickel in berylliumcopper alloys, and that, accordingly, the formation of more amount of electrically good conductive α-phase than that in the other alloys can be attained. The results of tensile and impact tests on 0.2% Be-Ni-Cu alloys were also shown. The large variation of the grain size of quenched alloys as well as the age-hardenability by tempering may be the chief causes of the change in impact or elongation values of tempered alloys. The cause of the grain refinement of 0.2% Be-Ni-Cu alloys with the increase in nickel was also considered.

抄録全体を表示

The difference in Age-hardening of Binary alloys of aluminium with 5.11 per cent copper, 1.20 per cent silicon, 9.98 per cent magnesium, and 1.395 per cent (calculated value) magnesium silicide (0.057 per cent excess magnesium) has been studied, at 200° by hardness measurements and microscopic examination.
The principal results of the present investigation may be summarized as follows-
1. There was practically no difference in the maximum hardness of all alloys except Aluminiumsilicon alloy, which was lower than any other alloys.
2. The present resnets are cited to show that the quantity of precipitate is not the criterion of the extent of Age (temper)-hardening. However, the relation between the rate of attaining the maximum hardening and the rate of supersaturation is accurately expressed by a simple empirical equation. That is
ap=0.00545×Hp^1.823
Where, ap=The rate of supersaturation
={(The Concentration of solute at quenched condition, in atomic per cent.)-(The limit of solubility at ageing-temperature 200° in atomic per cent.)}/(The limit of solubility at ageing-temperature, in atomic per cent.) Hp={(The maximum hardness value after aged at 200°)-(The initial-as quenched-hardness value)}/(The initial hardness value)
In other word, the relation between the lagarithm of the rate of maximum age-hardening and the logarithm of the rate of supersaturation is accurately expressed by a straight line.
3. On all alloys, the signs of a precipitate were visible before hardening was well advanced.
4. The anomalous behavior of hardness was observed at the softening process of age-hardening curves on all alloys. And, this “anomaly” could be explained by the aid of microscope. Namely, the softening process was found to occur in three steps, with the growth of oriented precipitate, the devision of oriented precipitate, and the coagulation of shorter, rounded particles.

抄録全体を表示

A new fatigue testing machine specially designed far this test was used. The general principle of this machine is that the inertia force of the fly wheel, oscillated by an eccentric mechanism, is transmitted as an alternating moment to the specimen. This moment can be estimated by calculation from the observed amplitude and frequency of the vibration of the fly wheel. The specimen can be clamped at any angle θ to the axis of the fly wheel. When the angle θ makes 0 degree, cycles of reversed torsionall moment are applied to the specimen and when θ is 90 degree, cycles of reversed uniform bending moment are applied, while any desired combination of bending and torsion is available by an appropriate choice of the 'value of θ. It will be noted that the bending moment and torque are in phase so that they reach their maximum and minimum value simultaneously.
The material used for this test is duralmin D-26 and D-24 shown in table 1, and the following conclusions are obtained.
(1) Fatigue failure of duralmin D-26 and D-24 are in close accordance with the criterions of constant maximum shear stress and constant shear energy respectively.
(2) The criterion has no relation to the limit of the number of. Stress cycles which determines the fatiguee limit.
(3) Every fracture is consistent with failure by maximum shear stress excluding specimens of D-24 at, simple bending.

抄録全体を表示