Friction stir welding (FSW) is a solid state joining method for metal and is widely used for

Al-Alloys. In the present work ,temperature distributions were investigated for Aluminum alloy

(7008), the effect of the main welding parameters such as rotational speed (tool speed) and liner

speed (welding speed) on the temperature distribution were investigated .The results show that the

rotational speed has a strong effect on the temperature distribution and this effect increases with

temperature increase, but the linear speed has an (inverse proportion) with the temperature increase.

This effect was less than the rotational speed. Peak temperature was estimated theoretically by

using (Bakingham ) theorem to derivate the relationship between the dimensionless heat input and

dimensionless peak temperature. In this study a mechanical test (tensile test) for welded specimen

was investigated to study the effect of temperature distribution on the mechanical properties of the

alloy, results show that Aluminum alloy (7008) was weldable on the (FSW) process and obtain an

maximum weld efficiency (81%) with parameters (880 rpm) rotational speed and (1 mm/sec)

welding speed. By comparing test results with peak temperature to the Al-Alloy the obtained result

was that the welding process is successful when welding temperature be (75-80%) of melting point

of the used material.