Tig Alın Kaynaklı Alüminyum Birleştirmelerin Mikroyapı ve Mekanik Özelliklerinin SKP ve T6 Isıl İşlemi Yoluyla Kaynak Sonrası Modifikasyonu Üzerine Bir Araştırma

Year 2022, Volume: 63 Issue: 708, 511 - 524, 16.09.2022

Gökçe Mehmet Gençer , Coşkun Yolcu , Fatih Kahraman

https://doi.org/10.46399/muhendismakina.1090266

Abstract

Ergitme kaynağı ile birleştirme endüstrinin her alanında yaygın olarak uygulanan imalat yöntemlerindendir. Özellikle yüksek ısıl iletim ve genleşme katsayısına sahip, sıvı halde hidrojen çözünürlüğü yüksek olan ve yüzeyinde rijit oksit tabakası bulunan alüminyum alaşımlarının ergitme kaynağıyla imalatında iri tane oluşumu, mekanik özelliklerde düşüş vb. olumsuzluklar gerçekleşebilmektedir. Bu nedenle ergitme kaynaklı birleştirmelerin ömürleri ve mukavemetleri açısından kaynak sonrası işlem ile kaynak bölgesinin iç yapı ve mekanik özelliklerinin iyileştirilmesi çoğu uygulama için önemli rol oynamaktadır. Çalışmamızda, tungsten inert gaz (TIG) kaynağı ile birleştirilen AA6082-T6 plakaların kaynak bölgesi özelliklerine kaynak sonrası işlem olarak uygulanan sürtünme karıştırma prosesi (SKP) ve T6 ısıl işleminin etkileri araştırılmıştır. SKP ve T6 ısıl işleminin mekanik özelliklere ve iç yapıya etkileri çekme testi, mikrosertlik testi ve mikroyapı incelemeleri ile araştırılmıştır. SKP ile kaynak dolgusunun işlem gören bölgesindeki (karıştırma bölgesi) dendritik tanelerin parçalanarak ince taneli iç yapının elde edildiği tespit edilmiştir. Bununla birlikte, SKP’nin malzemede oluşturduğu ısıl girdi ile ısıdan etkilenen bölgenin (IEB) genişlemesine ve sertliğin daha geniş bölgede düşmesine sebep olduğu gözlemlenmiştir. Kaynak sonrası uygulanan T6 ısıl işlemi ile kaynaklı birleştirmenin mekanik özelliklerin arttırıldığı ancak tokluğunun azaldığı gözlemlenmiştir.

Keywords

TIG kaynağı, alüminyum alaşımı, alın kaynağı, sürtünme karıştırma prosesi, T6 ısıl işlemi

Supporting Institution

We are grateful to Mustafa SAYAR and Türev Mechatronics employees for their valuable support.

Project Number

-

A Survey on Post-Weld Modification of Microstructural and Mechanical Properties of GTAWed Aluminum Butt Joints Through FSP and T6 Heat Treatment

Abstract

Fusion welding is a commonly applied manufacturing process in all fields of industry. Some imperfections (formation of coarse-grained microstructure, decrease in mechanical property, etc.) can occur especially in the fusion welding-based fabrication of aluminum alloys which have specific features, such as having high thermal conductivity, expansion coefficient, high hydrogen solubility in the liquid state, and oxide layer on the surface. Therefore, the enhancement of microstructure and mechanical properties in terms of the lifespan and strength of the fusion-welded joints is crucial for most applications. In the study, the effects of friction stir processing (FSP) and T6 heat treatment, applied as post-weld processing, on the weld zone properties of the gas tungsten arc welded (GTAWed) AA6082 plates were investigated. The effects of the post-weld processings (FSP and T6 heat treatment) on mechanical and microstructural features were analyzed via microstructural examination and microhardness measurements and tensile strength testing. It was observed that the dendritic microstructure in the processed region (stir zone) of the weld bead was destroyed and fine-grained microstructure was formed via FSP. Additionally, the findings showed that heat input occurred during FSP led to broaden of heat affected zone (HAZ) and decrease the hardness in a wider region. It was also determined that the mechanical characteristics of the GTAWed joint were increased but in contrast, the toughness was decreased through T6 post-weld heat treatment.

Keywords

GTA welding, aluminum alloy, Butt welding, friction stir processing, T6 heat treatment

Project Number

-

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