Study on Surface Hardness and Microstructure of 2A12 Al Alloy Friction Stir Weld Seam
The present research of friction stir welds focuses on the interior of welded joint while ignoring the surface.The study was developed on the microstructure morphology and microhardness of 2A12 alloy not only about the cross section but also on the surface of the weld seam.Compared with the cross-section,the results show that,the HAZ on the surface is misty.The hardness curves on the cross-section generates the type of "W" but "fang" type on the surface.The TMAZ was narrower and the distortions of its grain are severer and the deformation of grains are tangent to the direction of weld seam.The changes of hardness gradient of TMAZ on the surface is largest and the hardness is lowest.The hardness of the zone is 68.3％ of BM.Affected by top forging force of the shoulder and cooling conditions,the surface hardness is greater higher than that of cross section at the weld center.The TMAZ on the surface is the weakest zone of weld seam.
NETL
NSTL
万方数据
维普
