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8.93×10~5～1.293×10~6K/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 produced by single-roller rapidly solidification method. Microstructure of the ribbons was studied by TEM, rapid solidification cooling rate was estimated according to the heat transport equilibrium equation. The results show that when the line speed of the roll surface is between 18 m/s and 24 m/s, cooling rate can get to 8.93 × 10~5 ～ 1. 293 × 10~6 K/s, as the cooling rate increases, the thickness of the alloy ribbon decreases. Rapid solidification cooling rate has great impact on the microstructure of the ribbon, since rapidly solidification can increase the solid solubility, reduce the segregation and refine the grain, microstructure of the ribbon becomes much finer to form nanocrystalline. Cooling rate gradient was developed in the melted metal in the direction of vertical to the roll surface because of the rapidly solidification, which results in stress concentration in the inner crystal.
参考文献
| [1] | 岳译新,谭澄宇,郑子樵,李世晨,叶建军.新型Ag-Cu-Ge钎料的性能及钎焊界面特征[J].中国有色金属学报,2006(10):1793-1798. |
| [2] | 黄伯云;李成功;石力开.中国材料工程大典[M].北京:化学工业出版社,2006:471. |
| [3] | 崔大田,王志法,周俊,姜国圣,吴化波.Au-20.1Ag-2.5Si-2.5Ge新型中温钎料的组织与性能[J].中国有色金属学报,2007(09):1501-1505. |
| [4] | 崔大田,王志法,吴化波,刘金文.新型Au-19.25Ag-12.80Ge钎料的制备及性能[J].稀有金属材料与工程,2008(04):690-693. |
| [5] | 崔大田,王志法,周俊,吴化波,刘金文.新型Au-Ag-Ge钎料的性能及焊接界面特征[J].中南大学学报（自然科学版）,2007(06):1050-1054. |
| [6] | Ruhl R C.Theoretical analysis of ribbon formation during melt spinning[J].Materials Science and Engineering,1967(01):313-3320. |
| [7] | 沈宁福;汤亚力;关绍康 等.凝固理论进展与快速凝固[J].金属学报,1996,32(07):673-684. |
| [8] | 杨扬,徐锦锋,翟秋亚.急冷条件下Cu-Sn合金的快速枝晶生长[J].中国有色金属学报,2007(09):1521-1526. |
| [9] | 徐锦锋,魏炳波.急冷快速凝固过程中液相流动与组织形成的相关规律[J].物理学报,2004(06):1909-1915. |
| [10] | 向青春,周彼德,李荣德.快速凝固过程中熔液自旋工艺的比较[J].特种铸造及有色合金,2000(03):46-49. |
| [11] | 张国栋 .单辊成形装置及快冷软钎料的研制[D].甘肃工业大学,1999. |
| [12] | Walker J L;St Piere G R.The Physical Chemistry of Process Metallurgy,Part 2,Interscience[M].New York,1959:845-8853. |
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