Segregation Effect on Solidification Cracking in Spot Welding of the 6XXX Aluminum

Q2 Engineering

Engineering Transactions Pub Date : 2020-11-20 DOI:10.24423/ENGTRANS.1185.20201120

Andrés Ramírez, J. Graciano-Uribe, Diego Hincapie Zuluga, Edwar Torrez Lopez

{"title":"Segregation Effect on Solidification Cracking in Spot Welding of the 6XXX Aluminum","authors":"Andrés Ramírez, J. Graciano-Uribe, Diego Hincapie Zuluga, Edwar Torrez Lopez","doi":"10.24423/ENGTRANS.1185.20201120","DOIUrl":null,"url":null,"abstract":"Solidification cracking is a critical phenomenon, especially in the welding of AA6XXX, due these alloys present a wider freezing temperature range. The amount of liquid at the end of the solidification is a dominant factor in promoting or reducing the number of cracks. This paper proposes to assess the effect of the heat input in controlling the cracking during the spot welding in AA6061-T6. Four deposit conditions, made with GTAW, were assessed, in which the cracking degree was quantified and compared with the resulting microstructure. This work confirms and explains why the heat input governs the constitutional cooling, which simultaneously controls the microsegregation amount. With low heat input, the segregation is interdendritic, and the eutectic liquid gathers within the grains, which reduces the cracking susceptibility. A high heat input promotes the higher accumulation of eutectic liquid at the grain boundaries, facilitating cracks’ formation and growth. A high concentration of eutectic liquid promotes the healing effect, reducing the formation of cracks.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"68 1","pages":"417-431"},"PeriodicalIF":0.0000,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Engineering Transactions","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.24423/ENGTRANS.1185.20201120","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Engineering","Score":null,"Total":0}

引用次数: 1

Abstract

Solidification cracking is a critical phenomenon, especially in the welding of AA6XXX, due these alloys present a wider freezing temperature range. The amount of liquid at the end of the solidification is a dominant factor in promoting or reducing the number of cracks. This paper proposes to assess the effect of the heat input in controlling the cracking during the spot welding in AA6061-T6. Four deposit conditions, made with GTAW, were assessed, in which the cracking degree was quantified and compared with the resulting microstructure. This work confirms and explains why the heat input governs the constitutional cooling, which simultaneously controls the microsegregation amount. With low heat input, the segregation is interdendritic, and the eutectic liquid gathers within the grains, which reduces the cracking susceptibility. A high heat input promotes the higher accumulation of eutectic liquid at the grain boundaries, facilitating cracks’ formation and growth. A high concentration of eutectic liquid promotes the healing effect, reducing the formation of cracks.

查看原文本刊更多论文

6XXX铝点焊凝固裂纹的偏析效应

凝固开裂是一种关键现象，尤其是在AA6XXX的焊接中，因为这些合金具有更宽的凝固温度范围。凝固结束时的液体量是促进或减少裂纹数量的主要因素。本文提出在AA6061-T6点焊过程中，评估热输入对控制裂纹的影响。评估了用GTAW制成的四种沉积条件，其中对开裂程度进行了量化，并与所得微观结构进行了比较。这项工作证实并解释了为什么热量输入控制着结构冷却，同时控制着微偏析量。在低热量输入的情况下，偏析是枝晶间的，共晶液体聚集在晶粒内，这降低了开裂敏感性。高的热输入促进了共晶液体在晶界处的更高积累，促进了裂纹的形成和生长。高浓度的共晶液体可以促进愈合效果，减少裂纹的形成。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Engineering Transactions Engineering-Engineering (all)

CiteScore

1.40

自引率

0.00%

发文量

期刊介绍： Engineering Transactions (formerly Rozprawy Inżynierskie) is a refereed international journal founded in 1952. The journal promotes research and practice in engineering science and provides a forum for interdisciplinary publications combining mechanics with: Material science, Mechatronics, Biomechanics and Biotechnologies, Environmental science, Photonics, Information technologies, Other engineering applications. The journal publishes original papers covering a broad area of research activities including: experimental and hybrid techniques, analytical and numerical approaches. Review articles and special issues are also welcome. Following long tradition, all articles are peer reviewed and our expert referees ensure that the papers accepted for publication comply with high scientific standards. Engineering Transactions is a quarterly journal intended to be interesting and useful for the researchers and practitioners in academic and industrial communities.