The interaction of hafnium boride and chromium in the HfB2–Cr system is studied. Solid-phase interaction occurs at temperatures up to 1650 ± 30°C to form chromium boride (Cr2B) on the chromium side of the HfB2–Cr system. The diffusion of boron from hafnium diboride to chromium is the control link of this interaction process. At 1650 ± 30°C, a liquid phase of eutectic composition with a contact angle on hafnium diboride of 20° shows up in the reaction area. The interaction proceeds with the dissolution of each contacting element in the eutectic, equalizing their concentrations through liquid-phase diffusion. The eutectic nature of the quasibinary HfB2–Cr phase diagram, a small contact angle formed by the eutectic on hafnium diboride, decreasing with higher temperature, and high chromium vapor pressure, promoting uniform chromium distribution over the entire charge through the vapor phase allow chromium to be considered a promising addition that activates the sintering of hafnium diboride.

中文翻译：

---

准二元 HfB2-Cr 体系中的组分相互作用机制

研究了 HfB2-Cr 系统中硼化铪和铬的相互作用。固相相互作用发生在高达 1650 ± 30°C 的温度下，在 HfB2-Cr 系统的铬侧形成硼化铬 (Cr2B)。硼从二硼化铪向铬的扩散是这一相互作用过程的控制环节。在 1650±30°C 时，反应区出现了与二硼化铪接触角为 20° 的共晶组成液相。相互作用随着共晶中每个接触元素的溶解而进行，通过液相扩散平衡它们的浓度。准二元 HfB2-Cr 相图的共晶性质，共晶在二硼化铪上形成的小接触角，随温度升高而降低，铬蒸气压高，