Characteristics of ZrAl intermetallic crystals during solidification of aluminum wrought alloys

锻铝合金凝固过程中ZrAl金属间化合物晶体的特性

• 批准号: 372063-2009
• 负责人: Chen, XGrant
• 金额: $ 1.68万
• 依托单位: Université du Québec à Chicoutimi
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=483868
• 关键词: Characteristics; ZrAl; intermetallic; crystals; during

Zirconium is often added in aluminum wrought alloys to refine the grains, increase the strength and provide a better resistance to recrystallization. However, the addition of Zr may lead to the precipitation of undesirable zirconium intermetallic crystals and cause a number of casting process related problems and defects in the cast products. It is observed in some cases that interaction of Zr with other alloying elements (Fe, V, Ti and B) and poisoning effect of Zr on the Ti and TiB2 grain refinement have a great detrimental effect on the properties of final products. The main objective of this study is to better understand the effect of zirconium and its intermetallics on the fabrication processes and final product properties. Using thermodynamic calculation and physical experiments under controlled conditions, the formation of zirconium intermetallics and the solubility limit of zirconium in a typical 7xxx alloy will be investigated. The impact of the Zr level and the cooling condition on the nucleation, growth and morphology of zirconium intermetallic crystals will be examined using optical metallography and scanning and transmission electron microscopes. The mechanisms of the interaction of Zr with other alloying elements (Fe, V, Ti and B) in term of intermetallic formation, grain refinement and anti-recrystallization will be systematically studied. After the characterization of zirconium intermetallics in a typical alloy, the research will go through the 7xxx series alloy family to analyze the impact of complex Zr bearing intermetallics and to evaluate the resulted material properties. The information gained through this study can greatly help the aluminum industry to enhance the productivity and product quality for a number of important wrought alloys.

通常在铝合金中添加锆，以细化晶粒，提高强度，并提供更好的抗再结晶性能。然而，添加Zr会导致不理想的锆金属间化合物晶体的析出，并在铸件中引起许多与铸造工艺有关的问题和缺陷。结果表明，在某些情况下，Zr与其他合金元素(Fe、V、Ti、B)的相互作用以及对钛和TiB_2的毒害作用对最终产品的性能有很大的不利影响。这项研究的主要目的是更好地了解锆及其金属间化合物对制造工艺和最终产品性能的影响。通过热力学计算和控制条件下的物理实验，研究了典型的7xxxx合金中锆金属间化合物的形成和锆的溶解极限。利用光学金相、扫描和透射电子显微镜研究了不同的Zr含量和冷却条件对锆金属间化合物晶体形核、生长和形貌的影响。从金属间化合物的形成、细化晶粒和抗再结晶等方面系统地研究了Zr与其他合金元素(Fe、V、Ti、B)的相互作用机理。在对一种典型合金中的锆金属间化合物进行表征后，本研究将通过7xxx系列合金家族来分析复杂的含锆金属间化合物的影响，并对所得到的材料性能进行评估。通过这项研究获得的信息可以极大地帮助铝工业提高一些重要变形合金的生产率和产品质量。