Fundamentals of grain coalescence and applications to aluminum alloy industrial solidification processes

晶粒聚结基础及其在铝合金工业凝固过程中的应用

• 批准号: RGPIN-2016-03656
• 负责人: Phillion, Andre
• 金额: $ 2.04万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=638207
• 关键词: Fundamentals; grain; coalescence; applications; aluminum

Near-net-shape casting provides the most cost-effective way to manufacture light metal alloy components of complex shape. However, casting defects such as hot tearing reduce product quality and process efficiency. Hot tearing is characterized as a spontaneous failure of semi-solid metallic alloys due to the rupture of liquid films between grains, and occurs near the end of solidification where deformation becomes localized to the grain boundaries. The occurrence of hot tearing is intimately linked with the semi-solid’s gradual evolution from isolated grains surrounded by liquid to a coherent and percolated solid network, a process known as grain coalescence. If grain coalescence is retarded and therefore finishes at lower temperatures, hot tearing susceptibility is significantly increased.

近终形铸造为复杂形状的轻金属合金零件的制造提供了最经济有效的方法。然而，热裂等铸造缺陷降低了产品质量和工艺效率。热裂的特征是半固态金属合金由于晶粒之间的液膜破裂而自发失效，并且在接近凝固结束时发生，其中变形变得局部化到晶界。热裂的发生与半固体从被液体包围的孤立颗粒逐渐演变成连贯和分散的固体网络密切相关，这一过程称为颗粒聚结。如果晶粒聚结被延迟并因此在较低温度下完成，则热裂敏感性显著增加。