Partial Phase Diagram of the Ternary System Co–B–Si in the Co-rich Region

抄録

The ternary system Co–B(<35 at%)–Si(<35 at%) was studied by X-ray diffraction, optical and scanning electron microscopy, and thermal analysis of the annealed alloys.
The isothermal section at 1000°C, the vertical section at 15 at% B and the liquidus surface of the system were constructed.
The principal results were summarized as follows:
(1) No ternary compound appeared in the composition range investigated.
(2) The reactions at main three invariant points were; L(Co-16.5 at% B-5.5 at% Si, 1090°C)+Co₃B=α–Co+Co₂B, L(Co-13 at% B-12 at% Si, 1050°C)+α–Co=ε–Co+Co₂B, L(Co-12.5 at% B-13 at% Si, 1035°C)=ε–Co+Co₂B+Co₂Si.