Cu-Ni-Be系合金の研究(第2報) Cu-Be系及びCu-Ni-Be系平衡状態圖

抄録

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.