LAUSR

ABSTRACT The 773 K isothermal section of the Dy–Ni–Si ternary system was investigated and constructed by X-ray powder diffraction in this paper. Eighteen ternary phases (DyNiSi, DyNi2Si2, DyNiSi2, Dy2Ni3Si5, DyNiSi3, Dy2NiSi3, Dy3Ni6Si2, DyNi10Si2, Dy4NiSi7, DyNi2Si, DyNi5Si3, DyNi4Si, Dy3NiSi2, DyNi6Si6, Dy8Ni31Si11, Dy3Ni2Si4, Dy4Ni5Si and Dy9Ni2Si14) were confirmed to exist in this work. In those ternary phases, Dy9Ni2Si14 is a new phase, Dy2NiSi3 and Dy4NiSi7 have solid solution phenomena and the solid solution ranges are Dy33.3Ni14.7–18.7Si52–48 and Dy4Ni0.3–1.2Si7.7–6.8, respectively. We constructed 14 two phase regions and 52 three phase regions in the Dy–Ni–Si ternary phase diagram at 773 K. Because the phase relation is not very clear between 66.7 and 50 Si at.% in the Dy–Si binary system, we use dot lines to estimate tentative phase regions in this region.