Hi Svn,

Analyzing this case requires identifying its conditions to find a reasonable sequence for events.

alloy composition?

microstructure (at welded and non-welded regions)?

axial load & rotational torque?

linear & rotational speeds of rotating friction tool?

pressure applied by fixtures (high/moderate/low)?

process vibration (high/low)?

Regards

Hi Mr. Hanuman,

Although your question is not that clear to me according to my understanding, you should apply friction stir welding as first choice. However, you should explore more about the input conditions and tool dimensions within the limits of your FSW machine for obtaining a sound joint. Hugely available FSW data base may help you, please refer open literature.

Best regards

I am totally agree with Heider Y. Thamir & Buchibabu Vicharapu answers where you are needing to mention the experiment conditions to be able to discuss your case.

Fortheremore, there are several researcher studied Al-Zn aluminium alloy such as the below article:

https://link.springer.com/chapter/10.1007/978-3-319-48179-1_85

In this article, an investigation Al-Zn-Mg alloy AA7039 was friction stir welded (FSW) successfully employing a rotary speed of 635 rpm and welding speed of 75 mm/min. The joint efficiency of friction stir welded joint was 85.59 %. 

So that I suggest you try to apply these conditions at first and then check your results.

In some cases, the fixation method for specimens is wrong and bad result can be achieved.

If you think this answer help you, please try to recommend it.

The exact welding parameters will also depend on your tool geometry. Also agree with Mr. Thamir, if you give us more details on your experimental setup we can give you better answers.