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采用单辊快速凝固法制备了Au-19.25Ag-12.80Ge合金薄带。利用TEM方法对合金薄带的显微组织进行了观察分析,根据热传输平衡方程对快速凝固过程冷却速率进行估算。结果表明:辊面线速度在18~24 m/s范围内时,快速凝固冷却速率可达8.93×105~1.293×106K/s,随着快速凝固冷却速率的增加,合金薄带厚度有所减小;单辊快速凝固工艺的冷却速率对合金薄带的显微组织有重要影响,由于快速凝固工艺增加了材料的固溶度,减小了成分偏析,细化了晶粒,因此显微组织更加均匀细小,形成了纳米晶,快速冷却工艺在金属熔液内垂直于辊轮方向上产生的冷却速度梯度,造成了晶粒内部应力集中现象的产生。
Au-19.25Ag-12.80Ge alloy ribbons were prepared by single roll rapid solidification. The microstructure of the alloy ribbon was observed and analyzed by using the TEM method. The cooling rate of the rapid solidification process was estimated based on the heat transfer equilibrium equation. The results show that the rapid solidification cooling rate can reach 8.93 × 105 ~ 1.293 × 106K / s when the linear velocity of the roll is in the range of 18 ~ 24 m / s. With the rapid solidification cooling rate increasing, the thickness of the alloy strip decreases The cooling rate of the single-roll rapid solidification process has an important effect on the microstructure of the alloy ribbon. Due to the rapid solidification process, the solid solubility of the material is increased, the segregation of components is reduced and grains are refined. Therefore, the microstructure More uniform and smaller, forming a nanocrystalline, rapid cooling process in the molten metal perpendicular to the direction of the cooling roller speed gradient, resulting in the internal stress concentration phenomenon.