Effect of Temperature on Surface Cracking Defects in AA7075 Hot Extrusion

Tatsuya Funazuka; Kuniaki Dohda; Norio Takatsuji; Kaito Takano; Ngernbamrung Sukunthakan

doi:10.4028/p-6bfd8v

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HomeKey Engineering MaterialsKey Engineering Materials Vol. 926Effect of Temperature on Surface Cracking Defects...

Effect of Temperature on Surface Cracking Defects in AA7075 Hot Extrusion

Abstract:

Aluminum alloys in the 7000 series are high-strength alloys that are used in a wide variety of products in the transportation equipment and aerospace fields to reduce weight. In particular, the A7075 alloy has the highest strength and is expected to find further applications in a wide range of fields such as aircraft parts and sporting goods. However, low productivity is a problem due to its high deformation resistance, tendency to produce surface defects called tearing on the product surface, and short tool life. Tearing tends to occur under high temperature and high speed conditions, and is thought to be caused by local melting of Zn, an additive element, due to heat generation in processing. In this study, to improve the productivity of A7075 alloy, the profile was cooled during extrusion to prevent recrystallization of extrudate surface grains due to processing heat and to prevent processing heat during forming. In order to investigate the cooling effect, hot extrusion simulation was conducted. The cooling effect successfully suppressed the occurrence of tearing. These results indicate that cooling the extrudate during forming reduces the effect of heat generation during forming and prevents recrystallization of the extrudate surface grains and local melting of Zn.

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Periodical:

Key Engineering Materials (Volume 926)

Pages:

409-415

DOI:

https://doi.org/10.4028/p-6bfd8v

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Online since:

July 2022

Authors:

Tatsuya Funazuka*, Kuniaki Dohda, Norio Takatsuji, Kaito Takano, Ngernbamrung Sukunthakan

Keywords:

7075 Aluminum Alloy, Cooling, Hot Extrusion, Tearing

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Creative Commons CC BY 4.0

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* - Corresponding Author

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