Abstract The quasi-ternary TiB2-CrB2-WB2 was studied by means of hot pressing and pressureless dilatometry in the temperature range between 1650 and 2300 °C. Long-term annealing up to 14 h was necessary for equilibration. Thus, samples were obtained first by densification and then by subsequent cooling to the respective temperature with continuous annealing for up to 16 h in some cases. A large homogeneity range of a (Ti,W,Cr)B2 solid solution has been noticed. A new ternary γ-phase emerges from a critical tie line between (W,Cr,Ti)2B4 and α-(Ti,W,Cr)B2 solid solution at 1950 °C, spreads slightly into both the WB2 and CrB2 direction and decomposes by the peritectic reaction P: γ ⇆ α-(Ti,Cr,W)B2 + (W,Cr,Ti)2B4 + Liquid at 2170 ± 30 °C. At 2050 °C γ reacts with the CrB2-WB2-rich liquid according to the transition equilibrium T: δ-(Ti,Cr,W)B2 + (W,Cr,Ti)2B4 ⇆ γ + Liquid. The γ-phase possesses the composition of (Ti0.31W0.63Cr0.06)B2 expanding slightly towards the TiB2 and WB2-corner depending on temperature. It is clearly characterized by broad 00l x-ray reflections and a small c/a-ratio of 1.005–1.010 which implies a layerwise accumulation and differentiation of Cr and W atoms in the basal plane of the AlB2-type structure. FESEM and TEM studies reveal spinodal decomposition products at nanometer scale as well as coherent platelet-shaped W2B4 and β-WB precipitates of nanometer thickness.

中文翻译：

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TiB2-CrB2-WB2 系统中的新三元相

摘要 采用热压法和无压膨胀法在1650~2300℃温度范围内研究了准三元TiB2-CrB2-WB2。平衡需要长达 14 小时的长期退火。因此，在某些情况下，首先通过致密化然后冷却至相应温度并连续退火长达 16 小时来获得样品。已经注意到 (Ti,W,Cr)B2 固溶体的大均匀性范围。在 1950 °C 时，(W,Cr,Ti)2B4 和 α-(Ti,W,Cr)B2 固溶体之间的临界连接线出现了一个新的三元 γ 相，向 WB2 和 CrB2 方向略微扩散并分解由包晶反应 P: γ ⇆ α-(Ti,Cr,W)B2 + (W,Cr,Ti)2B4 + 液体在 2170 ± 30 °C。在 2050 °C 时，γ 根据过渡平衡 T 与富含 CrB2-WB2 的液体反应：δ-(Ti,Cr,W)B2 + (W,Cr, Ti)2B4 ⇆ γ + 液体。γ 相具有 (Ti0.31W0.63Cr0.06)B2 的组成，根据温度向 TiB2 和 WB2 角略微膨胀。它的明显特征是广泛的 00l x 射线反射和 1.005-1.010 的小 c/a 比，这意味着 Cr 和 W 原子在 AlB2 型结构的基面中的分层积累和分化。FESEM 和 TEM 研究揭示了纳米尺度的旋节线分解产物以及纳米厚度的连贯片状 W2B4 和 β-WB 沉淀物。010 这意味着在 AlB2 型结构的基面中 Cr 和 W 原子的层状积累和分化。FESEM 和 TEM 研究揭示了纳米尺度的旋节线分解产物以及纳米厚度的连贯片状 W2B4 和 β-WB 沉淀物。010 这意味着 Cr 和 W 原子在 AlB2 型结构的基面中逐层积累和分化。FESEM 和 TEM 研究揭示了纳米尺度的旋节线分解产物以及纳米厚度的连贯片状 W2B4 和 β-WB 沉淀物。