6061 forging stock Ti composition 1

[SVanden]

We buy 6061 forging stock, and a vendor is specifying 0.05% max Ti. Our in-house spec calls out 0.05-0.15%, and the ASM handbook calls out .15%. I know that the Ti helps with grain refinement, but to what extent?
It also helps by reducing problems associated w/overheating, doesn't it?
Will reducing it to .05 max make a major difference in our grain structures and/or mechanical properties?

Thanks
Svanden

 

[metengr]

Here are two web sites that contain technical papers on the deliberate additions of Al-Ti-B and Al-Ti master alloys to aluminium alloys and the affects of titanium content. It appears that the reason for the .15% spec is to assure TiAl3 particles exist in the melt for nucleation of grains (grain refinement).

http://www.iisc.ernet.in/~academy/matersci/bmsaug2001/345.pdf

http://www.lsm.co.uk/l_a.htm